22nd March 2015
Revision 1

Including some of the Rainbow Micro Hydro Instruction Manual
Issue #3 October 1995



Chapter 1 .....Safety

Electrical Safety
Turbine Safety
Pipe Suction

Chapter 2 ..... Description

Optimum Power
Battery Based System
Multiple Power Sources
Control Box

Chapter 3 ... Installation

Chapter 4 ... Installing Water Supply

Water Source
Pipe Siting
Gate Valves
Water Hammer
Outlet Drain Plumbing

Chapter 5... Electrical Wiring AC Transmission

Siting Considerations
Lightning Damage
Hydro to Control Box
Short Circuit Protection
Load Dump
DC to Battery
Regulator Interaction
Switching Regulators
Shunt Regulators

Chapter 6... Adjustment

Nozzles page
Nozzle alignment
Power Limit
Control Knobs
Turbine Speed
Generator Voltage
Output Voltage
Output Power
Indicator Lights

Chapter 7 ... Periodic Maintenance

Load Dump
Runner page
Type of Grease

Chapter 8...TroubleShooting

Appendix A... Site Considerations

Selection of Pipe Size
Estimating Power Output
Suggested Pipe Sizes
Internal pipe diameter
PVC pipe

Appendix B ...Pelton Wheel Performance

Appendix C Head Loss

Appendix D imperial/metric units!

Appendix E: Nozzle Combinations

Appendix F: Cable Sizing

Appendix G: Technical Information

Appendix H ... Environmental Impact



Congratulations! You have just bought our well tested micro hydro generator. This is an Australian made product adaptable to a range of sites and not a one-off unit, custom made for your site. As a result, parts are interchangeable and available. There is even a resale option! The standard model has been specially designed to work in a great variety of sites at a respectable efficiency. Many of these units have been running for twenty years as they are well supported and documented.

Please take note of safety issues as discussed below. Chapter 3 provides a point by point summarised installation guide. If you need more information on installation you can refer to the subsequent Chapters.

Chapter 1, Safety.

Some aspects of this turbine/generator present safety hazards unless careful attention is paid to proper installation.

*Electrical Safety

The power from the generator is at voltages comparable to conventional mains power. Contact with a live conductor may be lethal. Particular care should be given to the insulation and protection of the transmission cable. This cable must be installed under the supervision of a licensed electrician, to Australian Standard AS3000 and to the specifications as set out in Chapter 5 (Battery and Electrical). Never perform any work on the transmission cable without turning the water supply to the pelton wheel off (Refer Chapter 5).

*Turbine Safety

An important safety issue concerns the turbine. Children love poking sticks into things which spin around. Bits of the wheel could break off and get in their eyes at high velocity. Loose clothing could also be wound in by the rotating wheel causing injuries to fingers. If the turbine site is likely to be frequented by children then the unit must be kept in a locked shed.

*Pipe Suction

The provision of an intake filter at the water source, while being important to prevent turbine damage and pipe blockage, is also required to stop small animals and children's hands from being sucked into the pipe (Refer Chapter 4). FILTER

*Site safety

The only recorded fatality from micro hydros has been from falling down a waterfall. Creek beds are dangerous. Effort building a safe walking track to the intake and to the turbine site is not wasted.

Chapter 2:

Flowtrack Micro Hydro Description


Turbine Impeller Type: 132mm diam.
pelton wheel Impeller Material: Cast Epoxy Resin Composite
Flow Control: Changeable Nozzles
Maximum Nozzle:4 x 12.8mm Minimum Nozzle: 1 x 2.3mm Maximum
Head: 80m Maximum .... 4m minimum
Flow: 7 litres/second maximum, Minimum Flow: 0.2 litres/second
Generator Type: Capacitively excited 3 phase 4 pole induction motor
(or permanent magnet conversion for low head sites)
Cooling: (TEFC) Shaft mounted fan
Generator Voltage: 350VAC Maximum
Power: 300W Speed Control: Adjustable capacitors
Charger/Control box Type: High frequency switch mode variable ratio
Regulated Output Voltage Range: 12.5 to 16.5 V DC (for 12v version)
Input-Output Electrical Isolation: >2500V
Regulation: Adjustable Shunt Regulator
Load: Air Cooled Element

*Optimum Power Available at Minimal Flow:

The main advantage with the hydro having a battery based system is that you do not need to match the hydro to the current draw of the loads. The hydro output can be significantly lower than the peak power consumption of the loads with the battery acting as storage and capable of handling surges. In this manner, the pelton wheel can be charging the battery when the loads are off, thereby making good use of the continuing water flow. A hydro to operate loads directly would need to be a much larger unit to cope with peak loads and hence would require a much greater water volume.

*Battery Based System:

With the energy stored in the battery carrying short duration heavy loads such as power tools, washing machines, vacuum cleaners and irons. The turbine can appear to be 10 times the size as one with no storage. This is the reason our unit uses so little water compared to more conventional 240 volt micro-hydro generation systems which have no battery storage.

* Multiple Power Source Integration:

Another advantage of having a battery centred system is that it facilitates the incorporation of other charging systems into the one network. Solar panels, gen-set, wind generators, or other power sources can be simply connected into the same battery bank and will all power your system whatever the weather.

* Regulation of Other Power Sources:

Note that the voltage regulator in the hydro unit will only control hydro power and cannot dump surplus power from other sources. Their regulation must be independently looked after by using a general purpose shunt regulator with diode or switching regulator to take care of solar panels. The trend in PV installations is to use very clever controllers that try to optimise battery management. This can lead to classic "two controller" arguments and the solar controller can be tricked into thinking that the battery does not need a boost charge. Also these controllers boast "depth of discharge" and daily amp-hour displays which can be upset if the hydro current is not routed through the same shunt as the solar power.

* Maintenance:

The only wearing parts are the nozzles and the runner which are easily replaced and the two standard ball races which are very lightly stressed. There are no brushes to wear out and the machine is able to run for years without overhaul. Short periods of inundation are tolerated if the generator is soon taken apart and dried and has bearings repacked. The rotor has extra paint as it takes very little rust to jam the 1/2mm air gap. Stainless 6204 ball races are availiable if the generator is expected to go underwater very often.

* Hardware:

The welded aluminium chassis makes this pelton wheel unit very quiet and accurate construction makes vibration imperceptible. You will notice that the water actually flows THROUGH the spray chamber chassis walls which are constructed from rectangular extruded aluminium. This avoids the cost of complicated plumbing to distribute the water to the nozzles. It also increases rigidity, reduces noise, retains air to dampen water hammer, and even acts as a final gravel trap. The wheel itself is brittle, but wear resistant. The light weight of the resin pelton wheel is actually an advantage as bearing loads and imbalance are reduced. Its lack of flywheel effect is of no consequence in a continuously running machine like this.

* Generator:

The generator is a three-phase 415 volt induction motor which works even better as a generator. After ten years experimenting with many types of generator, we have decided that this is the best for versatility, robustness, efficiency, cost, availability and lifespan.

* Control Box:

The control box serves the multiple purpose of exciting the generator, reducing the voltage to 12, 24, 48 or 100, shedding excess power not wanted by the battery, and acting as a control box with ampmeter, voltmeter, fuse, indicator lights and connectors for the output wires. To prevent the output voltage from rising past that set on the regulator knob, the power is redirected to the dump load which is an electric water heating element surrounded by aluminium air heating fins. This seems to many an unconscionable waste of energy, and some other load diversion could be arranged, or some means of reducing the water pressure, but the method we have adopted is cost- effective and reliable. It is perhaps best thought of as a voltage control of last resort. (the permanent magnet option for very low head uses a Flowtrack Downconverter as the controller)

* Performance:

There are detailled tables in Appendix B, but the performance of any hydro-electric system is of course no better than its supply of water, so read on!

Chapter 3: Installation

1/ Select a suitable site for the turbine. It should be located to provide the most pressure and optimum flow for the most cost effective combination of pipe and transmission cable. Cable is cheaper than pipe, so optimise the penstock.
2/ Ensure the site is not subject to flooding.
3/ Facilitate access for both water and electrical wiring.
4/ Clear the area of weeds and obstructions.
5/ Consider having the hydro in a shed or enclosure to reduce noise and provide extra protection against the environment and/or having the hydro bolted down onto a floor or fixed structure.
6/ Provide a tail water drain to prevent flooding and erosion damage by the spent water.
7/ Install the water pipes, connectors, gate valve etc. WARNING - A poorly designed penstock may cause pressure surges resulting in damage to the turbine or pipe. Full detailed instructions on the proper installation of a penstock are given in Chapter 4. We urge you to study this information before purchasing or laying the pipe. Pay particular attention to the selection of pipe sizes and methods of avoiding airlocks.
8/ Fit an intake filter. WARNING: Failure to use an intake filter may result in damage to the turbine or pipe.
9/ Assemble the supplied gate valve, pressure gauge and Camlock fitting as shown in the diagram on this page.
10/ Using suitable bushings or adaptors (not supplied) to fit this assembly to the end of the penstock. The Flowtrack Micro Hydro comes equipped with a 2 1/2" BSP fitting.
11/ Fill the penstock with water, flushing to ensure all air has been expelled. Follow the procedure as set out in Chapter 4.
12/ Fit the camlock to the pelton housing. Use grease to make this easier.
13/ Install the control box close to the battery to minimise battery cable loss. This is particularly important with the 12 and 24 volt systems but is not so critical with the 48 and 100 volt systems. Refer to Appendix F for cable sizing data.
14/ Ensure ample ventilation for the battery, control box and particularly the load dump resistor. Place all electrical fittings clear of corrosive fumes emitted from the battery. Refer to Australian Standards AS 2676.1, AS 3000, and AS 3011.1 for additional information.
15/ Ensure the battery is suitable for the supplied unit (12, 24, 48 or 100 volt).
16/ Connect suitable cables between control box and battery (see Chapter 5).
17/ Connect the power transmission cable to the generator and fit the supplied plug at the control box end. This work must be performed by a qualified electrician.
Closely follow the detailed instructions and advice given in Chapter 5.
18/ Proceed with operation and adjustment of the machine as described in Chapter 6.

Components of the Water Supply:

Hydro electric generators have specific requirements for the method of water delivery to ensure a cost effective working head and a consistent, reliable water supply free of gravel and debris. The standard components of the water supply include intake, headrace, forebay, penstock and tailrace although for many micro-hydro applications the intake and forebay are one and the same without a headrace separating them.

head definition The intake is the structure which diverts water from the stream in order to supply water for the hydro. The intake should be designed so that enough water can pass through to keep the pipeline full and to prevent air from being drawn into the pipeline. A trashrack to keep out floating debris and stones is often included. Usually this consists of vertical steel bars across the intake channel. In order to minimise the intake of bed-load, the intake should be placed above the level where a natural sediment deposition tendency exists. It must be placed however sufficiently below the water surface that intake vortices do not occurr as air sucked in will cause air locks and rough, noisy turbine running. It is also important that the intake structure is "monotonically descending" so that air in the pipe can rise and escape out the untake.
The headrace if used is a pipeline or canal that conveys the water from the intake to the forebay, useful in some creeks to site the penstock better and to get air out of the water.
The forebay is a final settling area, with trashrack, just before the water enters the penstock. The depth of the forebay must be sufficient to prevent the formation of a vortex at the penstock entrance. A filter should be installed with a large surface area and sufficiently fine to prevent the intake of particles too large to pass through the nozzle of the hydro. A good trashrack may prevent stones and floating debris from clogging up the filter. Two stage filters are a good idea.
The penstock is the pipe used to convey water from the forebay (or intake) to the turbine. This pipeline is of great importance to the performance of a micro-hydro power plant. The size of the penstock and its ability to withstand the pressure of the water must be carefully selected in order to optimise the performance of the hydro and to prevent problems during operation.
The tailrace is after the turbine where the water is usually returned to the stream downstream of the headrace.

Chapter 4: Installing the Water Supply.

The first essential is to have enough water and enough head. The reliability of this supply is also a factor and if it fails at the dry time of year, then there will have to be a substantial back-up system such as solar, wind, diesel, etc.

* Water Source.

Ideally there will be a small dam at the source of the water. The dam serves several useful purposes:
1. It stores enough water to fill the pipe in one go without sucking air.
2. It stores enough water to flush the pipe of air and silt.
3. It secures the pipe well in floods.
4. It allows time for sand to settle and air bubbles to rise before being sucked into the pipe.
5. If installed as per diagram above, it is self priming and eliminates the need for a syphon.
Often only the cement powder needs to be carried to the source as sand and rocks are usually present in the stream bed. Preferably the wall of the dam is on bedrock for adhesion. The rock must be roughened with a hammer or pick before attaching the cement, otherwise the thin layer of moss and algae present on stream rock will prevent the cement sticking. The water can be kept away from the wet cement with a big syphon pipe, or by setting in a short length of pipe through the wall at the lowest place and later capping it or turning it off.

Headwall construction is obviously easier to do when the creek is low, but still surprisingly possible when there is lots of water. Plastic bags full of mortar are useful for poking in between rocks in fast-flowing sections. Mortar made dryish with 1:1 mixture can be made to stay in place under water and will set well without cracking because it is continuously wet. Allowing the mortar to 'gel' for half an hour will improve its resistance to washing away when applied under water. Addition of fast set compounds such as Cemquick can also help. Alternatively the water can be diverted with hessian sacks or plastic bags filled with dirt.

* Filter

There MUST be a filter at the inlet of the pipe. The most common cause of power failure in micro-hydro- electric systems is a clogged water intake! Gravel passing down the pipe will block and damage the nozzles. Getting rotten eels out of the pipe-work is difficult and very unpleasant! Platypus have been drowned by being sucked onto the ends of filterless pipes. Children's hands can also get stuck in pipes. If holes in the filter are too small they block too quickly. If the area of the filter is too small, blocking will be a problem. The sum of all the holes must have an area about ten times that of the end of the pipe. A coarse screen before a finer one is a good idea as leaves are caught by the first screen and don't stick over the fine mesh. In a big filter leaves will rot faster than they collect. Many people have theories about the stream washing rubbish off the filter. There is little evidence that filters are cleaned in this way.

Sometimes the bottom, or the top, of the filter will work better, subject to a variety of factors. Keep the filter midway between the bottom and the surface so that mud, silt and sand are not sucked up or too much floating debris is sucked onto the filter. A cover over the top of the filter can prevent a vortex from forming and sucking in air and floating debris.

The filter must also be STRONG so as to resist floods which roll rocks down stream beds. Location of the filter to one side of the stream can keep it out of the main force of the flooded stream. There are a number of commercially available filters suitable for the purpose. Contact your local pumping and filtration specialist for help.
Don't use galvanised wire or bolts on a filter. They last a remarkably short time in aerated acid water. Copper, stainless, brass and plastic are the materials to use.

* Pipe Siting & Layout

If at all possible, attempt to lay the pipe down a steep gradient immediately after the water source so as to develop sufficient pressure to overcome any humps or dips thereafter. Without such an initial gradient the suction can cause enlargement of air bubbles, collapsing of polypipe, and the suction of air through fittings. It is generally better practice to take the pipe down monotonically, ie with no humps and dips. Humps will tend to develop by themselves if any air is in the system as lower parts fill with water and lie lower because they are heavier, particularly if the pipe is on a soft surface, or hung between points like this: Pipe lays The diagram above illustrates how to lay a pipe so that air can get out the ends. Using a little extra length of pipe is better than having a pipeline which has a permanent air pocket losing head, or a pipe which keeps stopping. airlock The drawing above illustrates a common problem. The head lost directly subtracts from power at the turbine whatever the water flow, unless it is enough to entrain air and wash bubbles out of the line. Some pipes have insufficient gradient to achieve this flow rate, so the air lock remains as a fixture!

Even after all these precautions some pipes can refuse to start. Big pipes with slow gradients (1 in 10) are the hardest. One trick is to place joiners or "T" joints with gate valves every time there is an unavoidable hump as shown below.
flushing Stainless screws to let out air are another trick. Successive flushing from the source down can start even the worst of pipe runs. Silt and gravel can also be so cleared out, but usually pipes are blocked by air pockets. Special fittings that automatically dispel air are available.

* Syphons

Many people successfully run pipe intakes with a syphon as drawn below: SYPHON Systems like this are not necessarily self starting. If air gets into the pipe for any reason, such as the turbine exceeding the flow of the creek, turbulence washing bubbles into the intake, or dissolved air coming out of the water where the pipe lies in the sun, then the water can cease flowing and require complex measures to restart. Some of the methods used are:
1. sucking on the end of the pipe, 2. blowing into the end of the pipe, 3. driving water into the bottom of the pipe with a pump or another pipe, 4. wriggling the pipe, 5. filling the pipe with water using a bucket or another portion of pipe above the dam, 6. constructing a small dam so the inlet and first portion of the pipe are below the water level, 7. or simply leaving it alone in the hope that temperature variations will cause air in the pipe to expend and contract and start the syphon.

* Floods

Don't locate the turbine on a flood plain! It is tempting to do this to get all possible head, but this is false economy. If the whole turbine has been inundated in flood water the most sensitive parts are the bearings. The generator windings withstand submersion quite well (we give them an extra vacuum impregnation with varnish). Dry out the generator at the earliest opportunity as rusting quickly sets into the ball races, and the silicon steel laminations. Not much rust is needed to clog up the air gap and make disassembly a sledge hammer job! A rusted generator can be an expensive and difficult problem to solve.

It is an inherent problem with Pelton turbines that the tail water fall is wasted, unlike in axial flow tubines for example. Theoretically one could scavange up to ten metres of tail water fall by running a well proportioned exhaust pipe to below tail water level thus creating a vacuum in the spray chamber thus adding to the pressure drop accross the nozzles. There would of course be the danger of spray chamber flooding and you would have to put a moderately airtight seal on the generator shaft rather than the labyrinth thrower that we use to minimise friction.

* Weeds:

Grass can choke the generator fan and prevent rotation or obstruct cooling air. Unwanted tenants can take up residence. Black ants, slaters and cockroaches can get through small cracks and they all conduct electricity and leave remains which promote corrosion. In low power sites the fan can be removed. This improves efficiency, keeps the generator drier and also cleaner.
These problems can be avoided if the unit is housed in a small shed. This will also control that enemy of pelton wheels - COWS! They trip over pipes and cables and horn strange objects in their paddocks.

* Gate Valves.

gatevalve We will discuss below in more detail that gate valves should be operated slowly to prevent water hammer. A surprising point is that they can actually be damaged if they are left turned off incompletely. Cavitation under the gate can eat away the brass so that they will leak forever. This is not a catastrophic failure, but it is irritating when water squirts everywhere while you are trying to screw on a nozzle. Plastic globe valves have become cheaper than brass gate valves, but we dont recommend them. They are hard to operate smoothly, and have been found to break.

* Water Hammer.

If a pocket of air goes through the nozzle there is temporarily little obstruction to water flow and the often considerable mass of water in the pipeline accelerates (becasue air passes the nozzle far more easily than does water). It is quite common to have 200 kg of water travelling at 20 kph. When this hits the obstruction of the nozzle there is a sharp pressure surge against the nozzle. This water hammer creates forces up to 10 times the static head of the water and can burst pipe junctions, break fittings, blow off the nozzle caps or burst the casing.
The best remedy is to operate valves slowly taking 10 seconds to turn off the water. Anchorage of the pipe is also an important factor. Whipping of the pipe is the most destructive effect so the end of the line should be terminated in some manner as below.
treetie The tree takes most of the forces transferred down the pipe which relieves stresses on the intake manifold.

* Outlet Drain Plumbing

If the turbine is sitting on gravel, rocks or concrete the water can simply fall out of the spray chamber and run away, but in most installations there must be a pipe attached to the outlet, or a gutter of some sort constructed, otherwise run-off water will cause nuisance or erosion. Land slides, road damage and noise can also be produced by uncontrolled outfall.

When using too small a pipe for the exit water (less than 100 mm ID) there is a danger of water not getting away fast enough from the spray chamber. This can cause flooding of the chamber and wetting of the generator because the thrower fails. The wheel also has trouble spinning freely. It is important to install the outlet pipe with as much possible fall or gradient. It should be kept clear of weeds etc and regularly checked.

Some installations catch the waste water by locating the turbine on top of a tank and use a float switch in combination with an electric solenoid valve to turn off the water when the tank is full. If there are several households and/or an irrigation system using the water below then this may be a worthwhile measure to conserve water and at least still have some power during dry periods. There has often to be a compromise in the head used in order that the tank outlet is high enough to be useful. There may be in the order of 20,000 litres per day flowing into the tank if the turbine runs continuously. It may even be beneficial to the water system as the turbine and tank will act as a pressure reduction system.

Chapter 5: Electrical Wiring

*AC Transmission.

WARNING: The generator produces potentially lethal voltages. Any work on the transmission line must be performed under the supervision of a licensed electrician.
The electricity produced by the generator can be transmitted more than a kilometre with minimal loss. High voltage transmission is good from an efficiency point of view as there is very little energy loss. It is conventional to have the control box at the house or battery room so an eye can be kept on it.

* Siting Considerations

The pelton wheel should usually be located in the best place for plumbing, with the power transmission being treated as a secondary consideration. Electricity will go uphill without any resultant power loss!
Three phase wires and one earth wire of approximately 1mm˛, insulated to 600VAC standards are required. Flowtrack recommends the use of sheathed insulated cable for ease of installation and maximum protection. Underground wiring is preferable, but properly installed overhead wiring is acceptable. NB: All wiring should conform to Australian Standard AS 3000.

* Lightning Damage

Overhead wiring is more susceptible to lightning damage than underground, but all transmission lines are vulnerable. Direct hits are rare, but nearby strikes can induce damaging voltages. The control box incorporates reasonable protection, provided correct earthing procedures are followed. We offer a lightning hardened "dumb" controller which has the disadvantage of being very heavy and more site specific. Some locations have extreme lightning exposure and this has being the only option.

It is important to use an earthed neutral wiring system to reduce susceptibility to lightning induced surges and suppress radio interference. It is important for the earth connection (on the rear of the hydro control box) to be grounded. Do not earth the generator as well! Proper earthing will ensure consumer safety and proper operation of the lightning surge protection. Lightning protection is a complex issue. Refer to Australian Standard AS 1768.

* Connecting Hydro to Control Box

Connection to the control box is through a 4 pin plug and socket. The plug should be fitted to a flexible 600V rated sheathed lead. generator plug The colours shown on the instruction sheet with the plug are for IEC standard cables. Connection to the generator is made in the integral conduit box, which is part of the moulding of the generator housing. The wiring is usually "star" configuration as wired at the motor factory. If your site has greater than 50 metres head, then we recommend a "delta" configuration as shown below. This will improve the performance of your hydro with greater than 50 metres head.

* Short Circuit Protection

Short circuits either in the DC or the AC supply from the turbine will cause the generator to simply de-excite and pass only a small current into the short. When the short is removed the voltage should immediately come back up and damage is unlikely to have been caused. Re-excitiation is a property not all induction motors posess and some brands require "flashing" after a "soft" short. This can be done with a 12 volt battery. (see appendix G, part 4)
For this reason a disconnection switch is not needed on the wires from the generator. If the plug is pulled out of the control box then the generator ceases producing voltage after about 0.1 second.
The connection plug appears to be the wrong gender, but this is intentional as there is a chance of a shock from charge remaining on capacitors in the control box after the generator is disconnected.
NB: All wiring should be completed to the appropriate installation clauses of Australian Standard AS 3000.

* Load Dump

This finned aluminium heatsink disposes of surplus power by converting electrical energy into heat and dispersing this heat into the surrounding air. Note that the load dump is a 750W 240V hot water heating element and any alterations to this must be carried out by a licensed electrician. The voltage on the blue and brown wires can be as high as 350 volts DC, so correct installation and care is needed. It is tempting to connect the dump circuit to some low priority useful 240 volt load such as a water pump. This will not usually work as the dump is DC at varying voltages. The "dumb" version of the controller does not have a shunt and relies on having a regulator on the 12 volt output.
WARNING: The Load Dump gets hot during normal operation. Mount securely in upright position. Ensure free flow of cooling air. Keep out of reach of children. Keep flammable materials away, even though the design of the dump limits temperatures to below the flash point of most substances.

The load dump needs to be installed upright to encourage chimney effect. Cobwebs or anything obstructing free air movement around the Load Dump should be periodically removed. It can be located in a drying cupboard if you wish to use the surplus heat energy.
Note: the hydro Load Dump can only control energy from the turbine. Surplus energy from other power sources connected to the DC circuit (eg solar panels) cannot be disposed of by the hydro Load Dump, because the dump works in the AC voltage circuit before the power is converted to DC volts.
WARNING: The Load Dump connects to a Lethal Voltage. Do not disconnect when hydro is running. Any alterations to the Load Dump must be carried out by a qualified electrician.

* DC to Battery

Connecting Control Box to Battery The Control Box has two connectors for connection to the battery (of whatever voltage the control box is designed for). Connect the (red "+") terminal on the control box to the positive terminal of the battery and the negative (black "-") terminal to the battery negative using suitable insulated copper wire. Refer to Appendix F for cable sizing. Battery negative is normally earthed to reduce electrical interference and to ensure that the battery does not become live with respect to earth as a result of faulty power equipment. Refer to Australian Standards AS 3000 and AS 1768.

* Interaction with other Regulators

The hydro generator may be used in conjunction with other forms of energy production on the same battery. However, correct connection of this equipment and associated regulator depends on several factors. If another charging source forces the battery voltage above that set on the hydro regulator the control box will initiate a full dump causing the generator to de-excite. The turbine becomes unloaded allowing it to exceed normal operating speed. This may damage the unit, creates excessive noise and should be avoided.

* Switching Regulators.

Some types of solar switching regulators will cause this de-excitation to occur in cycles each time the panels are switched on. The interactions are quite complex and vary with battery type, state of charge, solar array size and hydro power output. Placing a suitable diode between the hydro and battery will prevent the interaction, but at a cost of energy lost in the diode. Also the voltage drop (typically over half a volt) will cause the hydro voltage meter to read slightly above the real battery voltage.

* Shunt Regulators.

Shunt regulators also show various problems with interaction. Care must be taken to ensure the hydro energy is not dumped by the solar shunt regulator unless it is large enough to control both the solar and hydro input. Small shunt regulators may be protected by a diode. Connect the solar shunt regulator to the panels and feed the power to the battery through a diode as shown. This will cause an error equal to the diode drop between the regulator voltage and the true battery voltage. When a diode is used in this way the blocking diodes supplied with some solar panels are not required.

Regulators supplied with wind generators are generally a shunt type. These are best treated similarly to small solar shunt regulators by connecting the generator and regulator and feeding the power through a diode to the battery.
If you are having difficulty combining the hydro with other systems please contact your dealer for advice. Our technical staff will also be happy to help if you contact us directly.

Chapter 6: Adjusting Pelton Wheel Nozzles

The Flowtrack pelton wheel has 4 nozzles. The maximum efficient nozzle size on this wheel is 12.8 mm diameter, so to get more water on the wheel at low heads we have used multiple nozzle locations. To get maximum power with a dynamic head of less than 25 metres you will need to use multiple nozzles. If you wish to either increase or reduce the water throughput or power output, refer to the nozzle sequence listed in Appendix E. (or just rely on trial and error!)

It may seem that the bigger nozzle will give more power, but this is true only up to a point. The benefit of more water consumption can be offset by reduced pressure if your pipeline is insufficiently large (see graphs page 19, 20). There will be an intermediate nozzle size which gives best power. The pressure gauge mounted on the gate valve will indicate failing pressure when too big a nozzle or too many is/are being used, or if there is some other pipeline problem. Lack of water, blocked filter, or persistent air locks will all reduce the pressure. Typically the maximum power is when about a qwuarter of the head is being wasted in pipe losses (eg the guage drops from 200 to 150 kPa when you turn on the valve).

* Nozzle Alignment.

There is a best angle for the water jet to hit the wheel, but this depends somewhat on the size of the nozzle. Very small nozzles may even work better when they are aimed to miss the centre divide in the pelton wheel cups! (wetted area reduction)
As the chazzis of this turbine is made of soft aluminium the alignment can be trued by simply bending the 25mm pipes holding the nozzles. This is done before sale, but exposure to high pressure or water hammer can upset the accuracy. There is a special tool for bending these pedestals without distorting the threads holding the nozzles to an oval shape. If you find the aim of the nozzles is poor then contact Flowtrack. (or if you dont need all four nozzles use the best ones). A 20 cent piece will block off unwanted nozzles.

* Sample Flow Rates

Power Limit: WARNING
If your site has good pressure and you have a generous pipe, it is possible to exceed the power rating of your pelton wheel unit. This will cause the fuse to blow. If you install the wrong fuse you may do damage to generator or electronics. When first setting up the unit, start with a small or medium nozzle and watch the ampmeter. With the voltage setting turned up to maximum, ensure that the amps don't go higher than 20 on the 12 volt model, 10 with the 24 volt model, 5 on the 48 volt model or 2.5 on the 100 volt model. There will be a maximum safe nozzle size, so take all nozzles larger than this and HIDE THEM!

* Control Knobs

The voltage regulator knob controls the float or maximum voltage of the battery. It sets the maximum voltage out. The speed and trim knobs are to adjust the hydro to the site. With the unit operating adjust the knobs to achieve maximum amps (see below).

* Turbine Speed

After selecting the correct nozzle(s), the control knobs on the control box can be adjusted. First turn the voltage regulator knob (refer to diagram of control box) fully clockwise (to 16 volts for a 12V unit, 32 volts for a 24V unit, 64 volts for a 48V unit or 128 volts for a 100 volt unit). The "SPEED" knob matches the turbine speed to the water speed. Efficiency is best when the speed is nearly half that of the water, so higher speeds match with higher pressures. Select one of the four positions on the switch which gives the most amps.

* Generator Voltage

The trim knob can now be set. Its function is to find the optimal generator voltage which depends on speed and power level. There are three marked positions on the switch with distinct clicks between positions which are not connected to avoid shorting the control box if the switch is operated while the generator is running. We recommend against rapidly switching between positions. The lower positions will allow more output at low power levels, while the higher positions will give more output from greater power levels.
Simply set the knobs for maximum amps. It is quite likely that position #1 will be best with a small nozzle, while position #3 may yield several more amps when a big nozzle is installed.

* Visual Adjustment

You can see at a glance whether the turbine is running at an efficient speed. The water will come off the wheel with minimum speed and sideways near the axle. If it continues forward as if straight through the wheel, then the wheel is too fast. If it deflects back towards the nozzle then it is too slow. The turbine noise will also be low at optimum speed. With familiarity the pitch of the noise is also an indicator of good tuning. Note that the trim knob will also affect the turbine spray pattern.

* Regulator

During the adjustment of the speed and trim knobs there may be a limitation due to the fact that the battery is fully charged. The amp meter shows current into the battery which will be reduced if the unit is regulating. When making these adjustments, the red regulating light should be off. Turn on some loads, if necessary, to reduce the voltage so that you have a full charging current to work with.
The inbuilt regulator can be manually adjusted to limit the current from the hydro when the battery voltage exceeds the voltage setting on the voltage regulator knob. If another shunt regulator is used to regulate your solar input for example, it is important that it is protected from the hydro output with a diode on the positive line (as per diagram).
Some "argument" may be seen between the hydro regulator and other regulators on the system (eg solar regulator). This erratic cutting in and out will not do any harm, setting the hydro regulator above or below the other will make it stabilise. Contact RPC for further advice if needed.
Next adjust the voltage regulator knob to a suitable float level for your batteries.
The generator will charge a battery up to the float voltage set on the "voltage control" knob at the top of the panel. The best float voltage depends on the type of battery, its condition and use regimen. This should be discussed with your battery supplier. For a 12V bank we recommend about 13.5 to 14 volts for lead-acid batteries and 14.5 to 15 for nickel cadmium batteries. The pelton wheel can actually be operated without a battery at all, but if loads greater than the wheels power output are connected then the voltage level will fall and some appliances such as inverters may interact in a very strange way. Even a small capacity battery will stabilise the system operation allowing surge loads and high currents to be carried without damage.
After a deep discharge it is advisable to increase the voltage by half a volt for a day or so. This should also be done once a month to equalise the cells and stir up the stratified electrolyte by bringing the batteries up to a gassing voltage. This is particularly important if the battery bank has been lying idle for a few months. The tiny bubbles created when charging a battery creates a stirring action which mixes the denser electrolyte at the bottom of the battery with the less dense electrolyte at the surface to make the overall mixture more uniform.
When the voltage limit is reached (as set on the voltage regulator knob) the power is diverted into the Load Dump and the regulating light will come on.

* Output Power

The power you can expect is indicated by the graph below. OUTPUT CURVES Note that the vertical scale is dynamic head, ie the real head minus the pipe losses. Pipe losses will be discussed later.

Depending on the operating point (head and flow at your site) the wheel is about 70% efficient, the generator about 75% and the control box and rectifier about 85%. The overall efficiency is the product of all 3 figures at every operating point. 40% efficiency is not achieved over a very big range of head and flow. Our machine excels in the enormous range of head and flow over which it will work. Most hydro-electric systems perform very badly at low power levels and many published performance graphs display extrapolated rather than measured data. The relatively low looking efficiency numbers we claim must be viewed in light of the fact that there is neglible transmission loss after the generator, and that there is a large operating area of head and flow the one machine can cover. "All year" efficiency is more important than peak efficiency. Also with renewable energy systems it is the output per dollar that matters as the fuel is free!

* Meters.

Both the output voltage and current are displayed on good quality meters so that electrical performance is easily seen.

* Indicator Lights.

DC Present (Top Green Light):. This light is on whenever there is DC voltage present in the Control Box. This is an indication that the battery bank is connected and the fuse isn't blown. (when the turbine is not running - otherwise it could be the source of the DC)
The voltmeter reads voltage at the cable terminating screws where the battery is connected, and so will continue to read the battery voltage when the fuse is blown. If the voltmeter and the green light disagree (light on with meter reading zero, or the other way around) then either the fuse is blown, the meter is stuck or the light is not working.

*AC Voltage

(Centre Orange Light): This light indicates that there is more than 70 volts present in the generator. At low generator speeds it will flicker with the cycles. This is normal.
It may extinguish while the machine is running on position 1 of the trim knob when the battery is under 10 volts. It will also extinguish if there is insufficient speed for build-up of the magnetism, or the trim knob is between positions.
Excitation speed is altered is altered by the position of the speed knob. Other causes of failure to excite may be a fault, such as shorted or open wires to the generator, slipping wheel, shorted transistors in the control box or load shed circuit, shorted output, clogged jet in nozzle, etc.

*Regulating (Bottom Red Light):

This light indicates when power is being dumped in the Load Dump. The amps on the amp meter will decrease when this light is on as the dump is disposing of power.


The fuse holder used requires the 3AG type fuse with a small amount of grease, petroleum jelly or other means of protection against tarnishing and developing a bad contact. For the 12 volt unit this should be a 25 amp, for the 24 volt unit a 15 amp, for the 48 volt unit a 7 amp or for the 100 volt unit a 4 amp fuse is used. Oversize fuses will fail to protect the electronic circuits. Note that the fuse will NOT blow if you short circuit either the DC output to the battery (without the battery connected) or the 240 volt output between the generator and the control box. Induction generators inherently will not pass much current into a low voltage (such as when there is a short circuit) as they lose excitation.

Chapter 7: Disassembly and Routine Maintenance.

*Load Dump Warning:

When the turbine is running, the wires to the load dump carry a dangerous voltage. Any work performed on the load dump should be carried out by a qualified electrician. Shut the turbine down and disconnect the battery before any disassembly is carried out.
You will find the Load Dump connected by a high voltage cable. If you need to disconnect this, the junction block may be accessed by removing the base from the heat dump. This reveals the wire terminals on the element. The green and yellow wire (earth) is meant to be connected to the case of the element. Do not connect it to either of the live pins!
It is essential that the machine is not run without the dump being connected, so screw the wires into the connector block carefully, making sure that the plastic coating on the wire is not preventing electrical contact.

* Runner.

The pelton wheel runner itself can be removed with a screwdriver and spanner to fit an 8 mm nut. The plastic of the runner is intentionally hard so as to resist sand which may be present in the water, and to help to reduce fatigue with age. This makes it brittle!
After long periods of time, the pelton wheel assembly may become hard to remove from the motor shaft. Take care not to damage the pelton wheel. If the assembly cannot be removed by gentle persuasion use the following instructions to remove the assembly safely. 1. Carefully study the diagram on the next page. 2. Find a suitable piece of timber (minimum 40mm thick) to use as a "pulling block". Ensure it will not damage the window seal, and drill a 10mm hole through the centre of it. 3. Remove the clamps, window and long 8mm bolt that secures the pelton wheel assembly. 4. Place a pile of rags or similar inside the spray chamber to soften any accidental dropping of the wheel. NB The pelton wheel is brittle and the shaft may release suddenly during this exercise! 5. Insert the 10mm long bolt supplied with your hydro through the wooden pulling block and carefully screw it into the end of the pelton wheel shaft until the bolt head starts bottoming on the wooden pulling block. Slowly continue to tighten the bolt until the pelton wheel assembly is pulled of the motor shaft. 6. Once the assembly is removed, use a wooden drift to separate the wheel from the shaft by gently tapping the shaft through the centre of the pelton wheel.
PS: The reason that this problem exists is that the shaft extension is fitted snugly to avoid runout, and it is made of aluminium which can cause corrosion against the mild steel shaft of the generator if it gets wet. Reassembly of the shaft extension should be with copious amounts of grease, preferably Neverseize. Some units have brass shaft extensions which are better, but VERY expensive.

* Generator.

Once the runner bolt has been withdrawn the generator can be unbolted and removed. The bearings can be accessed by unbolting the end bells from the generator with an allen key to fit 6 mm bolts. Tap the bells off with a drift and don't use a screwdriver to open up the crack as the very tight fit will be interfered with. This will upset the close air gap of the motor which could compromise build-up of voltage. The bearings can be removed from the shaft if necessary with a puller.

* Maintenance of Bearings.

The generator has a bearing housing of the fully enclosed type without lubricating nipples. The lubrication carried out prior to delivery is sufficient for several years service. The bearings should also last for several years. We suggest that the maintenance below be carried out by a mechanic or fitter.
Some bearing types have excessively tight seals and this costs considerable output power. Removing the garter springs is a good idea, and even removing the seals completely from the tail end causes no trouble so long as there is plenty of grease in the bells. Turbines dont usually live in dusty environments!
If the generator has become submerged in flood water the windings usually survive, but the grease washes out of the bearings if they are run wet and they rust up very quickly. Where flooding is likely we supply stainless steel bearings. The seals in ball races seem to keep water IN rather than OUT :=(
Another cause of failure from flooding is if there is a blockage in the drain holes we drill in the end bells. This causes a pool of water in the generator to reach the height of the rotor and the very small clearance between rotor and stator rusts up causing the generator to seize.
Before fresh grease is added, the bearing housing must be opened and cleaned of all old grease and traces of soap, which constitute the broken-down products of the grease.
Type of Grease A multi-purpose lithium based grease is recommended such as SHELL ALVANIA EP2, or CASTROL EPL2.

* Reassembly.

When reassembling the generator a small amount of grease on the machined surfaces of the bells will allow a more easy fit and delay corrosion. Some people heat up the bells a little to facilitate assembly. Be careful to notice the little drain holes in the end casting. These are to drain any water and if they are inadvertently put at the top they can allow the motor cavity to fill with water.
The only wearing parts in normal use are the two generator bearings. These are easily available ball races, Usually 6203 and 6204.
A "V" seal is located on the shaft and pushed up to the front bell of the motor. Note that the feather edge goes against the motor casting. Its function is to keep dirt out of the bearing, and water off the motor shaft which is mild steel and vulnerable to rusting.
The thrower behind the runner is efficient enough to keep the shaft quite dry and the only way water will get on the front bearing in normal use is through condensation while the machine is not running. This will evaporate when the machine is run as the generator produces warmth and air movement. Much of the energy loss in the generator is in its rotor and the heat is conducted out along the shaft, keeping it dry. When re-assembling the pelton wheel assembly, ensure that all surfaces are clean and liberally apply a high quality anti seizing compound before re-fitting.


The water filled housing (frame) of the machine simplifies the plumbing. The quick connect intake manifold makes for very easy assembly of the fittings on the end of the penstock (pipeline from creek). The gate valve supplied has a pressure gauge installed on the penstock side of the gate valve. This means that with the gate closed it reads static head and with the gate open it reads dynamic head. If this is less than 70% of the static head it indicates either too many nozzles or too large a nozzle is being used, or a loss of pressure due to a blocked intake filter, or air locks.

When changing nozzles be very careful that the new ones sit properly on their pedestal. If the nut does not screw down all the way it can be ejected by a pressure surge and hit the wheel, so breaking off a cup. A less catastrophic error is the nozzle not being aligned. The water jet will then not be aimed correctly and water leaking around the rim of the nozzle could hit the jet of water and spoil its focus as well.

Chapter 8: Trouble Shooting

If the pelton wheel unit stops charging, it is not always obvious which part of the system is at fault. It could be the water supply, mechanical problems, electronic problems, or cable faults. We have built into our machine a number of indicators to help locate problems quickly. As indicators themselves are prone to failure, we have also gone to some effort to protect them from the hostile environment in which they must work for many years.

The flow chart on the next page shows the questions you must ask, and the information you must use in arriving at a diagnosis of the problem. We start with the assumption that there is no power being generated by the pelton wheel unit, ie there is no current flowing in the output wires. Go to the centre of the chart where it says START. **************************************************************
faultfinder ********************************************************************

Appendix A: Site Considerations

* Measuring Head.

The height of the water source vertically above the turbine site can be assessed by:
1. Reading a contour map in hilly country. Contours are usually drawn in every 10 metres of altitude.
2. If a pipe already exists then a pressure gauge connected to the end of the pipe will give the height: just divide the reading in kPa by 10 and you will get the head in metres. The size or length of the pipe makes no difference to the pressure, so long as it is totally full of water and there is no water flowing through it (ie a tap on somewhere).
3. Alternately, the head can be measured by walking up the water course with a spirit level, or jar half fullof water! Hold the level with the bubble central and look along the top edge. The patch of ground you sight is the place you stand next. The number of times you do this before arriving at the source multiplied by the height of your eyes (say 1.7 metres) will give the head. survey
In very rough country the head can be estimated by comparing the height of rapids and waterfalls with adjacent trees, or by hanging a rope over! Quite accurate altitude measuring devices can now be bought. Even the GPS feature on a mobile phone may be sufficient.
Electronic devices that look like pocket calculators are used by surveyors and measure differences in height down to one metre. Similar devices are used by glider pilots and are called altimeters. The elevation of the turbine site is subtracted from the elevation of the water source to obtain the available head. Company staff are available to perform site assessments.

* Measuring Flow

The flow of water in a small stream may be measured by taking a plastic bucket (10 litres) to a small waterfall or narrows in the creek and timing how long it takes to fill. Try to direct the entire creek flow into the bucket.
A 10 litre bucket filled in 10 seconds means one litre per second, which is a practical flow. This measurement should be made at a time when the flow is average or in the dry season and not just after rain. There is no point installing a turbine that only works for two weeks a year!

*Selection of Pipe Size and Calculating Friction Loss.

Friction of water in pipes varies enormously with pipe size. Double the pipe diameter gives you 32 times the water! Another way of saying this is that one pipe size too small gives you half the electricity, and one size too big wastes considerable amounts of money on pipe.

What is the optimum pipe size? 1. Measure available (static) head by any of the methods as set out above.
2. Work out the length of pipe needed.
Measuring or pacing out the distance is the most reliable, but if the country is really rough you may have to use trigonometry! (or phone GPS) 3. Use the pipe size recommendations as set out on page 19 or contact Flowtrack p/l for performance predictions for given or advised pipe sizes.
NB: If your available head is in the order of 7 metres, any loss will cause disproportionate power loss as the generator efficiency is failing below this pressure.

* Estimating Electrical Output.

Now that the flow and the static head are both known, the dynamic head can be calculated by subtracting the friction losses of the pipe (relative to flow rate, pipe length and pipe diameter). The output from the machine can be read from the graphs on page 20. There are spreadsheets availiable from Flowtrack to help with optimisation.
If the hydro unit will produce four amps at 12 volts or 2 amps at 24 volts and accumulating over a 24 hour period each day, it will compete with more than four solar panels in most sites and charging when the sun isn't out! Less power may still be valuable when you consider that the hydro can run 24 hours per day in overcast periods when solar panels may not produce much power at all.

Suggested Pipe Diameters are tabled below, the principle being not to buy more plastic than necessary. Also it assumes there is not a shortage of water muchof the year, so it is a guide only. (OD):
( OD = Outside Diameter, assuming the use of standard metric polyethylene class 6 pipe.)


15 20 25 30 35 40 45 50 60 70 80 90 100 -> head<P>
pipe length
40 metres 90 75
50m 100 90 63
60m 100 90 63 50
70m 100 90 63 63 50
80m 100 90 63 63 50 50
90m 100 90 63 63 50 50 50
100m 100 90 75 63 63 50 50 40
120m 100 90 75 63 63 50 50 50 40
140m 125 100 75 63 63 50 50 50 50 40
160m 125 100 75 63 63 63 50 50 50 40 40
180m 125 100 75 75 63 63 50 50 50 40 40 40
200m 125 100 90 75 63 63 50 50 50 40 40 40 32
250m 100 90 75 63 63 63 50 50 50 40 40 40 32
300m 100 90 75 75 63 63 50 50 50 40 40 40 32
350m 90 75 75 63 63 63 50 50 50 40 40 40
400m 90 75 75 63 63 63 50 50 50 40 40 40
450m 90 75 63 63 63 63 50 50 40 40 40
500m 90 75 75 63 63 63 50 50 40 40 40
600m 75 75 63 63 63 50 50 50 40 40
700m 75 75 63 63 63 50 50 40 40
800m 75 63 63 63 50 50 50 40
900m 63 63 63 50 50 50 40 0
1Km 63 63 50 50 50 50
1.5 Km 63 50 50 50
2 Km 63 50 50

Note All the above pipe diameters are in millimetres (outside diameter) class 'B' polyethylene. The sizes are to give between 90% and 100% of maximum 300 W performance.
Where near maximum performance from the pelton wheel would never be required, a pipe diameter of one size smaller may be selected. Never select a pipe diameter of two sizes smaller as this may render the pelton wheel virtually useless.
One size bigger in pipe diameter is often more effective than two pipes operating in tandem. A section of smaller diameter pipe can undo most of the benefit of the larger pipe before and after it, depending on the relative pipe sizes and how much of the smaller pipe is used.
Between 5 metres and 10 metres head, 300 W is not achievable regardless of nozzle size and pipe size. Despite not being able to operate at close to maximum power the hydro would still be a valuable asset at these low heads.
Pipe sold in metric units is usually measured in outside diameter (OD) whereas pipe sold in imperial units is measured by inside diameter (ID).

* Internal Diameter.

Obviously it is the inside diameter (ID) of a pipe which determines its friction to the water. Pipe diameter measurement has been confusing because of conflicting conventions between ID and OD measurements and adopted standards for metric conversions. Unfortunately, the accepted standard for measuring 'metric' pipe is by OD whereas the 'imperial' convention has always been ID measurement. Some installations which have performed below expectations have resulted from this confusion. We recommend you actually measure the ID of the pipe to be used. Any fittings which the water must traverse will also have an effect on resultant pressure loss.
A factor often forgotten is that many plants and animals can cling to the walls inside the pipe. These make it thinner and rougher and can easily halve the output of the machine. To get an indication of this effect look at stones in the creek bed or ask neighbours, local poly-pipe suppliers, Department of Agriculture etc. If there is a crust on the rocks or there does seem to be a problem in your area then this must be allowed for and subtracted from the pipe radius.
Pipe friction is very counter-intuitive. The effect of diameter is fifth power, which means too small a pipe is much worse than you think. Also it means that a short section of thinner pipe or fittings with narrow ID will cost you more than you think in head.

*PVC versus Polyethylene.

When above 50mm OD it becomes very awkward transporting and laying poly pipe, particularly if it is in the higher pressure rating, making it stiffer, heavier and harder to install fittings. Also because it comes in a roll it can be hard to avoid undulations in the lay and these can become collection points for air which robs head. (airinpipe.gif)
PVC is easier to install and lies straighter. Its price has become competetive. Drainage standard pipe (DWV) is cheap but only good to about ten metres. Also it is liable to suck flat if the filter clogs! A snorkel can be used to minimise this risk. (snorkel.gif). PVC pressure pipe is much more expensive but practical. There are issues with it being fragile and UV sensitive. Fittings are often not available but the plastic and be made plastic (duh) by immersion in hot oil. Acrylic paint will stick to the surface to provide sun protection and camouflage.
There are possibly more environmental impacts with manufacturing PVC compared to Polyethylene.

Appendix B: Dynamic Head

The theoretic head is the elevation difference between the water intake and the turbine. Unfortunately, when the water is flowing through the pipe the pressure seen at the nozzle reduces. This actual head is called the dynamic head. The pressure loss is caused by pipe friction and by persistent air locks. The pipe friction loss depends strongly on the water consumption, the air lock loss less so. Pipe friction can be read from diagrams (nomographs) from the pipe supplier.
It is a shame that pipes are not transparent, as there usually are parasitic sections of air costing head in most systems. Air causes slow swinging of the pressure guage needle when you turn off the gate valve...

Appendix C:

*Pipe Performance Curves

Head Loss (metres per 100 metres) Polyethylene Pipe - Type 50 - Class 6 | PVC Nominal Pipe Diameter (OD for Metric and ID for Imperial)

Sheet 1

PIPE TYPE: 25mm 1" 32mm 1 1/4" 40mm 1 1/2" 50mm 2" 63mm 2 1/2" 75mm 3" 90mm 100mm 125mm
FLOW l/s
0.10 0.57 0.28 0.16 0.11 0.05 0.04 0.02 0.01 0.01 0 0 0 0 0 0
0.20 2.05 1.01 0.60 0.39 0.20 0.14 0.06 0.03 0.02 0.01 0.01 0 0 0 0
0.30 4.34 2.14 1.26 0.83 0.41 0.29 0.14 0.07 0.04 0.02 0.02 0.01 0.01 0 0
0.40 7.39 3.64 2.15 1.41 0.70 0.50 0.23 0.12 0.07 0.04 0.03 0.02 0.01 0.01 0
0.50 11.17 5.50 3.25 2.14 1.07 0.76 0.35 0.18 0.11 0.06 0.05 0.02 0.02 0.01 0
0.60 15.66 7.72 4.56 3 1.49 1.06 0.49 0.26 0.15 0.08 0.06 0.03 0.03 0.02 0.01
0.70 20.83 10.27 6.06 3.99 1.99 1.42 0.65 0.34 0.20 0.11 0.09 0.04 0.03 0.02 0.01
0.80 26.68 13.15 7.76 5.10 2.54 1.81 0.83 0.44 0.26 0.14 0.11 0.06 0.04 0.03 0.01
0.90 33.18 16.35 9.66 6.35 3.16 2.26 1.04 0.55 0.33 0.18 0.14 0.07 0.05 0.03 0.01
1 40.33 19.88 11.74 7.72 3.85 2.74 1.26 0.67 0.40 0.22 0.17 0.08 0.07 0.04 0.01
1.10 48.12 23.72 14 9.21 4.59 3.27 1.50 0.79 0.47 0.26 0.20 0.10 0.08 0.05 0.02
1.20 56.54 27.87 16.45 10.82 5.39 3.84 1.77 0.93 0.56 0.31 0.23 0.12 0.09 0.06 0.02
1.30 65.57 32.32 19.08 12.55 6.25 4.46 2.05 1.08 0.65 0.35 0.27 0.14 0.11 0.06 0.02
1.40 75.22 37.08 21.89 14.39 7.17 5.11 2.35 1.24 0.74 0.41 0.31 0.16 0.12 0.07 0.02
1.50 85.48 42.13 24.88 16.36 8.15 5.81 2.67 1.41 0.84 0.46 0.35 0.18 0.14 0.08 0.03
1.60 96.33 47.48 28.04 18.43 9.19 6.55 3.01 1.59 0.95 0.52 0.40 0.20 0.16 0.09 0.03
1.70 - 53.12 31.37 20.62 10.28 7.33 3.37 1.78 1.06 0.58 0.44 0.22 0.18 0.11 0.03
1.80 - 59.06 34.87 22.93 11.43 8.15 3.74 1.98 1.18 0.65 0.49 0.25 0.20 0.12 0.04
1.90 - 65.28 38.55 25.34 12.63 9.01 4.14 2.19 1.30 0.72 0.55 0.27 0.22 0.13 0.04
2 - 71.79 42.39 27.87 13.89 9.90 4.55 2.41 1.43 0.79 0.60 0.30 0.24 0.14 0.05
2.10 - 78.58 46.40 30.50 15.20 10.84 4.98 2.63 1.57 0.86 0.66 0.33 0.26 0.16 0.05
2.20 - 85.65 50.57 33.25 16.57 11.82 5.43 2.87 1.71 0.94 0.72 0.36 0.29 0.17 0.06
2.30 - 93 54.92 36.10 17.99 12.83 5.90 3.12 1.86 1.02 0.78 0.39 0.31 0.18 0.06
2.40 - - 59.42 39.07 19.47 13.88 6.38 3.37 2.01 1.11 0.84 0.42 0.34 0.20 0.07
2.50 - - 64.09 42.13 21 14.97 6.88 3.64 2.17 1.19 0.91 0.46 0.36 0.22 0.07
3 - - 89.84 59.06 29.44 20.99 9.65 5.10 3.04 1.67 1.27 0.64 0.51 0.30 0.10
3.50 - - - 78.58 39.17 27.93 12.83 6.78 4.04 2.22 1.69 0.85 0.68 0.40 0.13
4 - - - - 50.16 35.76 16.44 8.69 5.18 2.85 2.16 1.09 0.87 0.51 0.17
4.50 - - - - 62.39 44.48 20.44 10.81 6.44 3.54 2.69 1.36 1.08 0.64 0.21
5 - - - - 75.84 54.07 24.85 13.14 7.82 4.30 3.27 1.65 1.32 0.78 0.25
5.50 - - - - 90.48 64.51 29.65 15.67 9.34 5.14 3.90 1.97 1.57 0.93 0.30
6 - - - - - 75.80 34.84 18.41 10.97 6.03 4.59 2.31 1.84 1.09 0.36
6.50 - - - - - 87.91 40.40 21.36 12.72 7 5.32 2.68 2.14 1.26 0.41
7 - - - - - - 46.35 24.50 14.59 8.03 6.10 3.08 2.45 1.45 0.47
7.50 - - - - - - 52.67 27.84 16.58 9.12 6.94 3.50 2.79 1.65 0.54
8 - - - - - - 59.36 31.37 18.69 10.28 7.82 3.94 3.14 1.85 0.61
8.50 - - - - - - 66.41 35.10 20.91 11.50 8.75 4.41 3.51 2.08 0.68
9 - - - - - - 73.83 39.02 23.25 12.79 9.72 4.90 3.91 2.31 0.76
9.50 - - - - - - 81.61 43.14 25.70 14.13 10.75 5.42 4.32 2.55 0.84
10 - - - - - - 89.74 47.44 28.26 15.54 11.82 5.96 4.75 2.80 0.92
11 - - - - - - - 56.60 33.71 18.55 14.10 7.11 5.67 3.35 1.10
12 - - - - - - - 66.49 39.61 21.79 16.57 8.36 6.66 3.93 1.29
13 - - - - - - - 77.12 45.94 25.27 19.21 9.69 7.72 4.56 1.49
14 - - - - - - - 88.47 52.70 28.99 22.04 11.12 8.86 5.23 1.71
15 - - - - - - - - 59.89 32.94 25.05 12.63 10.07 5.94 1.95
16 - - - - - - - - 67.50 37.13 28.23 14.24 11.34 6.70 2.19
17 - - - - - - - - 75.52 41.54 31.58 15.93 12.69 7.49 2.46
18 - - - - - - - - 83.95 46.18 35.11 17.71 14.11 8.33 2.73
19 - - - - - - - - 92.80 51.04 38.81 19.58 15.60 9.21 3.02
20 - - - - - - - - - 56.13 42.68 21.53 17.15 10.13 3.32

Appendix D:

Pressure Conversion

The most common pressure measurement used is the kPa - kilopascal.
But also you see psi : pounds per square inch.
Sometimes you get bar - air pressure at sea level.
one psi = 6.89kPa
Most important for pelton wheel installations is that a pipe full of water will produce nearly 100 kPA for every 10 metres of height. This is about 14 psi, and about one bar, and corresponds to about 32 feet of altitude in a pipe full of water.

Appendix E: Nozzle Combinations

Our Pelton Wheel housing has provision for four nozzles.
The optimum number of nozzles depends on the water consumption and pressure.
Obviously there are an enormous number of combinations possible and one could simply proceed with trial and error, lookign for the maximum output of electricity.

However there are principles that will lead to an optimum arrangement quickly:
Nozzle efficiency falls above 10 mm and below 4mm. Water consumption is largely a matter of the combined nozzle area.
So for example a single 10 mm nozzle will be almost identical in performance to two 7 mm nozzles.
Four 9mm nozzles will consume about the same water as two 12 mm nozles, but will be more efficient.
One 4mm nozzle will work better than two 3mm nozzles.
Optimal nozzle sizes will be different for other brands of pelton wheel that may have bigger cups for example.
Twenty Cent coins will work to block off unwanted nozzle sites. All four nozzles are only needed for the extreme low head region of the output curve. The reason for our generous 2 1/2" manifold is to extend performance in this region.

As an indication of the likely water consumption and power achieved by different nozzle combinations the following table might be useful. The "Hydraulic Power" is used as an indication of output only. Actual power can vary between 40% of this and none at the extremes of low flow and head :-(
The table does however indicate that the turbine is useful at heads as low as 4 metres and flow as low as 1/3 litre per second. These figures are calculated, not measured. Theoretical water consumption can be wrong in underestimating wetted surface friction in small nozzels, and beam contraction in big ones.



HEAD kPa velocity 1 nozz Hyd. 1 nozz Hyd. 1 nozz Hyd. 1 nozz Hyd. 1 nozz Hyd. 1 nozz hydraulic
____ of water 4mm POWER 5mm POWER 7mm POWER 10mm POWER 12mm POWER 13mm POWER(w)
m/s litres/s l/s litres/s litres litres/s litres/s
1 9.80 4.43 0.05 0.44 0.07 0.69 0.14 1.35 0.28 2.76 0.41 3.97 0.48 4.66
2 19.60 6.26 0.06 1.25 0.12 2.28 0.20 3.83 0.40 7.81 0.57 11.24 0.67 13.19
3 29.40 7.67 0.08 2.29 0.14 4.19 0.24 7.03 0.49 14.34 0.70 20.65 0.82 24.24
4 39.20 8.85 0.09 3.53 0.16 6.45 0.28 10.82 0.56 22.08 0.81 31.80 0.95 37.32
5 49 9.90 0.10 4.94 0.18 9.02 0.31 15.12 0.63 30.86 0.91 44.44 1.06 52.15
6 58.80 10.84 0.11 6.49 0.20 11.86 0.34 19.88 0.69 40.57 0.99 58.42 1.17 68.56
7 68.60 11.71 0.12 8.18 0.22 14.94 0.37 25.05 0.75 51.12 1.07 73.61 1.26 86.39
8 78.40 12.52 0.13 9.99 0.23 18.25 0.39 30.60 0.80 62.46 1.15 89.94 1.35 105.55
9 88.20 13.28 0.14 11.92 0.25 21.78 0.41 36.52 0.84 74.53 1.22 107.32 1.43 125.95
10 98 14.00 0.14 13.97 0.26 25.51 0.44 42.77 0.89 87.29 1.28 125.69 1.51 147.51
11 107.80 14.68 0.15 16.11 0.27 29.43 0.46 49.34 0.93 100.70 1.35 145.01 1.58 170.19
12 117.60 15.34 0.16 18.36 0.29 33.54 0.48 56.22 0.98 114.74 1.40 165.23 1.65 193.91
13 127.40 15.96 0.16 20.70 0.30 37.81 0.50 63.40 1.02 129.38 1.46 186.31 1.72 218.65
14 137.20 16.57 0.17 23.13 0.31 42.26 0.52 70.85 1.05 144.59 1.52 208.21 1.78 244.36
15 147 17.15 0.17 25.66 0.32 46.87 0.53 78.57 1.09 160.36 1.57 230.91 1.84 271.00
16 156.80 17.71 0.18 28.26 0.33 51.63 0.55 86.56 1.13 176.66 1.62 254.38 1.90 298.55
17 166.60 18.25 0.19 30.96 0.34 56.55 0.57 94.80 1.16 193.47 1.67 278.60 1.96 326.97
18 176.40 18.78 0.19 33.73 0.35 61.61 0.59 103.29 1.19 210.79 1.72 303.54 2.02 356.24
19 186.20 19.30 0.20 36.58 0.36 66.81 0.60 112.01 1.23 228.60 1.77 329.19 2.07 386.34
20 196 19.80 0.20 39.50 0.37 72.16 0.62 120.97 1.26 246.88 1.81 355.51 2.13 417.23
21 205.80 20.29 0.21 42.50 0.38 77.63 0.63 130.16 1.29 265.63 1.86 382.51 2.18 448.91
22 215.60 20.77 0.21 45.57 0.39 83.25 0.65 139.57 1.32 284.83 1.90 410.15 2.23 481.36
23 225.40 21.23 0.22 48.71 0.39 88.99 0.66 149.19 1.35 304.47 1.95 438.43 2.28 514.55
24 235.20 21.69 0.22 51.93 0.40 94.85 0.68 159.02 1.38 324.54 1.99 467.33 2.33 548.47
25 245 22.14 0.23 55.20 0.41 100.84 0.69 169.07 1.41 345.03 2.03 496.84 2.38 583.10
26 254.80 22.57 0.23 58.55 0.42 106.95 0.70 179.31 1.44 365.94 2.07 526.95 2.43 618.44
27 264.60 23.00 0.23 61.96 0.43 113.18 0.72 189.75 1.46 387.25 2.11 557.64 2.47 654.46
28 274.40 23.43 0.24 65.43 0.44 119.53 0.73 200.39 1.49 408.96 2.15 588.91 2.52 691.15
29 284.20 23.84 0.24 68.97 0.44 125.99 0.74 211.22 1.52 431.07 2.18 620.74 2.56 728.50
30 294 24.25 0.25 72.57 0.45 132.56 0.76 222.24 1.54 453.55 2.22 653.12 2.61 766.51
31 303.80 24.65 0.25 76.23 0.46 139.24 0.77 233.45 1.57 476.42 2.26 686.05 2.65 805.15
32 313.60 25.04 0.25 79.95 0.47 146.03 0.78 244.83 1.59 499.66 2.29 719.51 2.69 844.42
33 323.40 25.43 0.26 83.72 0.47 152.93 0.79 256.40 1.62 523.26 2.33 753.50 2.73 884.31
34 333.20 25.81 0.26 87.56 0.48 159.94 0.80 268.14 1.64 547.23 2.36 788.00 2.78 924.81
35 343 26.19 0.27 91.45 0.49 167.04 0.82 280.06 1.67 571.54 2.40 823.02 2.82 965.91
36 352.80 26.56 0.27 95.39 0.49 174.25 0.83 292.14 1.69 596.21 2.43 858.55 2.86 1007.60
37 362.60 26.93 0.27 99.40 0.50 181.56 0.84 304.40 1.71 621.23 2.47 894.57 2.90 1049.87
38 372.40 27.29 0.28 103.45 0.51 188.97 0.85 316.82 1.74 646.58 2.50 931.08 2.93 1092.72
39 382.20 27.65 0.28 107.56 0.51 196.48 0.86 329.41 1.76 672.27 2.53 968.07 2.97 1136.14
40 392 28.00 0.29 111.73 0.52 204.09 0.87 342.16 1.78 698.29 2.57 1005.54 3.01 1180.12
41 401.80 28.35 0.29 115.94 0.53 211.79 0.88 355.07 1.80 724.64 2.60 1043.48 3.05 1224.65
42 411.60 28.69 0.29 120.21 0.53 219.58 0.89 368.14 1.83 751.31 2.63 1081.89 3.08 1269.72
43 421.40 29.03 0.30 124.53 0.54 227.47 0.91 381.37 1.85 778.31 2.66 1120.76 3.12 1315.34
44 431.20 29.37 0.30 128.90 0.55 235.45 0.92 394.75 1.87 805.61 2.69 1160.08 3.16 1361.49
45 441 29.70 0.30 133.32 0.55 243.53 0.93 408.28 1.89 833.23 2.72 1199.86 3.19 1408.16
46 450.80 30.03 0.31 137.79 0.56 251.69 0.94 421.97 1.91 861.16 2.75 1240.07 3.23 1455.36
47 460.60 30.35 0.31 142.30 0.56 259.94 0.95 435.80 1.93 889.39 2.78 1280.73 3.26 1503.08
48 470.40 30.67 0.31 146.87 0.57 268.28 0.96 449.79 1.95 917.93 2.81 1321.82 3.30 1551.30
49 480.20 30.99 0.32 151.48 0.58 276.71 0.97 463.91 1.97 946.76 2.84 1363.34 3.33 1600.03
50 490 31.30 0.32 156.14 0.58 285.22 0.98 478.19 1.99 975.89 2.87 1405.29 3.37 1649.26
51 499.80 31.62 0.32 160.85 0.59 293.82 0.99 492.61 2.01 1005.32 2.90 1447.66 3.40 1698.99
52 509.60 31.92 0.32 165.60 0.59 302.50 1.00 507.16 2.03 1035.03 2.92 1490.44 3.43 1749.20
53 519.40 32.23 0.33 170.40 0.60 311.27 1.00 521.86 2.05 1065.03 2.95 1533.64 3.47 1799.90
54 529.20 32.53 0.33 175.25 0.60 320.12 1.01 536.70 2.07 1095.31 2.98 1577.25 3.50 1851.08
55 539 32.83 0.33 180.14 0.61 329.06 1.02 551.68 2.09 1125.88 3.01 1621.27 3.53 1902.74
56 548.80 33.13 0.34 185.08 0.62 338.07 1.03 566.79 2.11 1156.72 3.04 1665.68 3.56 1954.86
57 558.60 33.42 0.34 190.06 0.62 347.17 1.04 582.04 2.13 1187.85 3.06 1710.50 3.59 2007.46
58 568.40 33.72 0.34 195.08 0.63 356.34 1.05 597.43 2.15 1219.24 3.09 1755.71 3.63 2060.52
59 578.20 34.01 0.35 200.15 0.63 365.60 1.06 612.95 2.16 1250.91 3.12 1801.31 3.66 2114.04
60 588 34.29 0.35 205.26 0.64 374.93 1.07 628.59 2.18 1282.85 3.14 1847.30 3.69 2168.01
61 597.80 34.58 0.35 210.41 0.64 384.35 1.08 644.37 2.20 1315.05 3.17 1893.67 3.72 2222.44
62 607.60 34.86 0.35 215.60 0.65 393.84 1.09 660.28 2.22 1347.52 3.19 1940.43 3.75 2277.31
63 617.40 35.14 0.36 220.84 0.65 403.40 1.10 676.32 2.24 1380.25 3.22 1987.56 3.78 2332.63
64 627.20 35.42 0.36 226.12 0.66 413.04 1.10 692.49 2.25 1413.25 3.24 2035.07 3.81 2388.39
65 637 35.69 0.36 231.44 0.66 422.76 1.11 708.78 2.27 1446.50 3.27 2082.96 3.84 2444.58
Pressure limit beyond this area
NB: calculated not measured data. ..Kali 22/3/ 2015

These figures are for each nozzle, so total water consumption and power can be arrived at by adding up the numbers relating to each nozzle, For example four 12mm nozzles at four metres head will consume 3.6 litres per second and yeild 127 watts of hydraulic power.
At this operating point a permanent magnet alternator would be needed bcause of the slow speed.

Note also that in the right lower area of the table the maximum power of the generator would be exceeded, and the spray chamber could flood if multiple nozzles were used. The figures are only included for perspective.

Cable Sizing

The cable from the generator to the control box is almost never an energy loss. Mere practicality ususally leads to a choice of at least 1 sq mm wire for the voltage rating and mechanical strength. At the voltage of the generator (100v to 300v) there is virtually no loss and runs of a kilometre are feasible.
The control box is placed close to the battery bank in most circumstances and that is the concept of course. Even in a 12v system there is not a problem sending 20 amps for a few metres.
In extreme cases however the calculations might have to be made. Resistance of a run of wire is :
r = 1.7 x length /100 A
where length is meters, A is square millimetres of copper, and r comes out as ohms. The voltage loss is of course then calculable by the classic Ohms Law:
v = Ir ....where I is the amps. Note that two wires imply two voltage drops!
Obviously voltage drop matters a lot more in a 12 volt system. As there are three phase wires leading from the generator it works out that you have to use the amps value i=power/volts*1.7*0.7

Appendix G: Additional Information for Electronic Technician


The electronics provides four important functions which have been condensed into the control box.
1. Excitation and speed control of the generator.
Induction generators require capacitors to supply the magnetising current and to tune out the winding reactance. The size of the capacitor effects speed, current and voltage of operation. Our circuit adds capacitors in four steps by adjusting the speed knob so as to match the speed of the generator to the best operating speed of the pelton wheel.
2. Load Dump.
This both regulates battery charge and limits over-voltage events if the battery is disconnected. The Load dump is attached by a 240V cable with 3 conductors. One is green and yellow, one is brown and one is blue. The green and yellow wire must be connected to the exposed metal parts of the dump for safety. If the machine is run with the output disconnected then there is the risk of the generator voltage and temperature becoming excessive. Surplus energy from other power sources connected to the 12 or 24 volt circuit (eg solar panels) cannot be disposed of by the hydro Load Dump because the dump works in the high voltage circuit before the power is converted to 12 or 24 volt.
The voltage on the blue and brown wires can be as high as 350 volts DC, so correct installation and care is needed. It is tempting to connect the dump circuit to some low priority useful 240 volt load such as a water pump. This will not usually work as the dump is DC at varying voltages.
If the generator voltage reaches 430 volts peak the Load Dump circuit acts to stop it going any higher by passing current to the Load Dump element. If the voltage control knob is turned lower than the battery voltage the current will also fall to zero and the red light will come on indicating that the power is being diverted away from the battery. If the battery is disconnected the total load must of course be diverted and the red light will come on.
To control over-voltage a transistor passes current to a resistor (750 watt immersion heater) sandwiched in an assembly of aluminium heat sinks. This reliably conducts the heat from the element and reduces the maximum temperatures reached to safe levels.
This load shedding function is also activated through an opto-coupler from the 12 volt side of the circuit if the output voltage has reached the level preset on the top (voltage) knob. The voltage being supplied to the resistor is DC varying from 0 to 240 volts according to the amount of power to be shed. There are no jumps or steps in its operation as the power fed to it has been chopped at 20 kHz with a varying mark/space ratio, and then filtered.
Many customers are offended by the "waste" of power in this energy dump resistor. There IS the possibility of using the power in a hot water heater, but elements over 1 kW may damage the control transistor. Also the element may burn out if there is a loss of water from the hot water tank. This may lead to the destruction of the pelton wheel electronics, or the overcharging of the batteries. One customer famously set the dump element in a rock wall of his house.
A better way of using surplus power is to sequence loads on the battery side with low priority loads turning on as the batteries reach full charge. Items like water pumps, hot water heating, ceiling fans or refrigerators can all be allocated a priority. A problem with many loads is that they are either switched on or off (all or nothing) and may cycle on and off frequently unless the control system is sufficiently intelligent.
If there is water storage at the source it is sometimes worth considering a solenoid to turn off the water to the pelton wheel when the battery reaches a preset level. Here again there is risk of cycling if sufficient time delays are not built in.

3. Rectifier and control box.
The power from the generator is 3 phase AC which is good for transmission over distance, but it is almost useless in this form. The voltage will vary from 100 to 300 and the frequency from 15 Hz to 100 Hz according to the setting on the control panel. Even if by chance the machine WAS running at 50 Hz 240 volt there would be little surge capacity past the continuous power the machine was running at, and most practical loads would not be carried - the generator would simply de-excite.
To avoid the frequency problem we rectify the generator output first to high voltage DC, then convert it to 12, 24, 48 or 100 volt using a ferrite transformer running at 20 kHz. This approach is used so as to avoid the use of three heavy, inefficient, expensive, low frequency transformers which would also worsen the build-up characteristics of the generator. (but we have to resort to this technology for the "dumb" lightning hard controller)
Driving into a bridge and converter the generator sees little load until it reaches 100 volts, so that little "over-speed" is necessary to make it excite.
This over-speed margin of typically 30% limits the minimum operating head as a situation can exist where charge would commence if sufficient speed could be attained to make the generator excite. With heads below 7 metres, or after the generator has been disassembled it may need a small pulse of current through the windings while it is stationary to reinstall residual magnetism. A torch battery is sufficient! Simply touch any two generator wires to the contacts of the battery for a second. This is called flashing, and is performed with other sorts of self excited generators also. Low head sites are better served by a permanent magnet generator which we make by altering the rotor of the usual generator. Unfortunately in a permanent magnet generator the field is not alterable so the machine cannot be tuned to suit different nozzle sizes or different heads. Changing the rotor would be the only option.
When the machine is used with long transmission wires with connections exposed to the weather excitation problems can be more common. The residual magnetism of the generator may only produce 1 volt, which may not pass dubious connections. If the 4 pin plug in the back of the control box is removed and a 12 volt battery applied across any two pins a small spark will indicate continuity and clean up any dubious contacts. This should make the machine build up when the plug is re-inserted.

4. Power Point Match.
The control box has voltage ratios available, controlled by the trim knob so as to allow the generator to operate at the most efficient voltage for a given power level. With too low a voltage there is predominant copper loss (and aluminium too in the rotor!) while too high a voltage means unnecessarily high flux levels and iron losses. The optimum can be approximated using the three taps on the transformer winding selected with the trim knob.

MPPT (maximum power point trackers) are now ubiquitous and cheap and well worth while for PV systems. It would be wonderful if they could be used on our water turbines as construction of our controller is not very economic and there is now no second source of these units. Also the devices only optimise voltage and not independently turbine speed; they cant optimise accross both dimensions. They also have been confused by the time delay a turbine takes to settle at an operating point. (Solar panels are fairly instantaneous in their reaction to a change in voltage.) This makes them tend to race to the lowest operating voltage.
B It is possible that MPPT units currently used on small wind turbines might work as they also have load dump options. (eg Windyboy)

* Fuse Protection.

The function of the fuse is to protect the diodes in the control box in the event of reverse battery connection or from excess current. The wires to the battery will also be protected if the diodes in the control box fail, allowing current to flow in reverse. The diodes can fail if exposed to very high voltage on the battery line (32 volt in a 12 volt system), or more likely as a result of lightning surges.

* Speed Knob.

This knob brings into operation different excitation capacitors on positions 3, 2 and 1. The effect of this is to reduce the speed of the generator by 30% each step. The actual speed is dependent on power level, and to a lesser extent on the trim knob setting; but for the purpose of finding an optimum point of operation the interaction is unimportant.
The capacitors are added to different phases so as to provide some measure of symmetry, but symmetry is not very important for the performance of induction machines and the higher ripple produced in the output is still low enough to cause no observable problems. The switching of high voltage capacitors is very hard on switch contacts which tend to spot weld together. Coils have been installed in the current paths to limit the 'make' currents to tolerable levels. Even so, we do not recommend excessive operation of this control while the machine is running.

* Electrical Subassemblies.

The control box has no user serviceable parts inside and does contain dangerous voltages. As it only weighs 3.5 kg it is intended to be sent back to the manufacturer or qualified repairer in the event of damage or failure. If, however, a competent electronics technician wishes to attempt a repair, we will supply subassemblies to simplify the job.
The oscillator and driver board is easily removed and it is only necessary to correctly sequence the wires to effect a repair. The transformer, heatsink and rectifier subassembly can be easily detached, but here there are several flying leads to get right.

* Spare Parts

Wherever possible we use common components that are readily available. Components that we make such as the coils, circuit boards, chokes and transformers are all available, and we feel it is very important to keep your system down-time as short as possible. There is no point spending great design effort on an efficient machine if it spends lengthy periods not operating. While several machines have operated for twenty years there are always the attacks from age, flood and lightning. One even succumbed to a shotgun.

Schematics of the controller are posted on the Flowtrack web page
They are in scems.zip and are readable with the DOS program SCHEDIT, the later Protel packages, or the Flowtrack open source program schematux on the DOWNLOADS page. (there is also an inferior windows version "Schemat3.exe" there).
Relevant files are: hydrocon.S01, hcomplet.S01, hdrive6.S01, hdrive7.S01, hydrodum.S01, hcomplet48.S01.
If anybody wanted to remake any of the PC boards it is likely that RPC would release the .PCB files - google Rainbow Power Company.

With the passage of time there has of course been great change in semiconductors and far better transistors are around since the first meagre BUZ41A and then the MPT6060. The most recent schematic diagram lists current devices, including, surprisingly, a dump catch diode based on silicon carbide semiconductor!

* Radio Frequency Interference (RFI).

High voltage DC is chopped up at 20 kHz by high voltage MOSFETS. These are wonderful switches as their drive power requirements are almost zero. They are cheap, they don't suffer from second breakdown and they are fast. Necessarily also, they generate lots of radio noise up to 10 MHz. We have taken great trouble to reduce this with snubbers, slow drive, filters and bypass capacitors, but still some noise gets out.
Earthing of the control box chassis will reduce this problem considerably. Earthing of your battery negative may also help. Schemes of earthing all to one point help a lot, particularly if there are long runs of transmission wire in your system which is the right length to radiate magnificently on the AM band. Our machine is not alone in creating this problem however.
Computers, alternators, wind generators, electric fences, low voltage fluorescent lights, electric motors, and inverters are all guilty to various extents. A contributing factor is that in many bush areas radio reception is very poor, and with the radio amplifying flat out to get a signal, it has very poor selectivity to shut out noise.
Often it is easier to put up a decent outdoor antenna to get a better signal, rather than persevere with reducing interference.
One thing in favour of our control box is that Schottky Barrier Rectifiers are used on the 12 volt side. As well as halving the energy loss at rectification, they don't have a "hard recovery" when the voltage across them reverses so you don't get the "door slamming in the wind" phenomenon that makes car alternators so noisy.

* Safety.

The power from the generator is enough to kill. In the typically wet circumstances of a hydro installation a good contact is likely. In the interests of safety, the high voltage is totally isolated from the DC output in the same manner as a battery charger. It is also isolated from the case of the electronics, and from the case of the motor. Earthing arrangements are so left up to the consumer, and will depend on the installation. If power is being transmitted any distance at AC, then isolation of the high voltage circuits is not possible because of capacitive coupling to ground, and the Multiple Earthed Neutral system (MEN) should be adopted. The negative of the battery bank should also be earthed. As previously noted, this work must be done by a qualified electrician.

Appendix H

* Environmental Impact.

It became a fashionable rumour that so many of the "alternate" sources of energy required more energy to produce than they ever could repay in their life-span. This made them a sort of non-rechargeable battery rather than a generation system. This may have been the case with early solar panels, but things have come a long way since then. Our pelton wheel stands up well to criticism. In a 10 year life span it would have produced the electricity otherwise requiring 15 tonnes of coal to be burned.
Even this sells it short, because really the energy cost of the grid reticulation which we are comparing with should include lots for the transmission lines - their manufacture, erection and protection. The grid infrastructure level is indicated by the $50,000+ connection cost that is typical, compared to the less than $2,000 cost of polypipe and cable for a micro-hydro installation. The costing is of course complicated by the fact that the mains option supplies more of the house systems than does a small hydro system and that other environmental impacts are made necessary by it, such as a gas stove. At the end of the sums, pelton wheels win easily.
The more local environmental issues are often the deciding arguments. Many people find power lines very offensive because of cleared forest under the wires, 4WD tracks to cause soil erosion, and unsightly poles and wires across the view. Underground lines are usually too expensive and impractical in rough country.
A frequent concern is that the water used by the turbine is "wasted" and that the usual watercourse will be deprived by the flow through the penstock. Water flow in the creek is certainly reduced, but the effect is less than might be expected. During dry times the pipe stops as there is no point running the turbine at 1/10 litre per second. The only time there is a noticeable difference is when the creek is lowish. No animals will be high and dry and no plants affected as they rely on ground-water. Water continually joins a creek bed on the way down so the proportion of water used for power is small.

Tail water from a hydro system must be controlled properly, otherwise soil erosion, land slips and dead trees can result. Anything from pipes to old sheets of iron can easily solve this problem. Our pelton wheel unit is predominantly made of aluminium which has a high environmental cost of production. Its long term environmental impact is modest however as its life is indefinite and it is recyclable. The lifespan of the machine is usually limited by damage in transit or during floods. Please tie it to an immovable object if there is any chance of a flood covering the site. The biggest risk to a turbine is being washed away.

Revised 21/3/2015 by Kali McLaughlin
Flowtrack p/l