Wind/Solar Hookup Basics and Beyond.

Three phase wind turbine wiring diagrams

Page 6



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The image above shows the recommended wiring diagram for a 3 phase wind turbine or water hydro.


We are asked daily -- How do I connect a 3 phase A/C wind turbine to a D/C battery bank (or charge controller?) -- Or The Controller that came with my 3 phase wind turbine failed, what do I need in order to make it work with your controller? Well it's really pretty simple, you just need a 3 phase rectifier! Yet, it's those details, breakers, switches, meters, loads and such, that are really needed to make everything work as they should. Shown above is how it all comes together, and hopefully the text below should leave you pretty knowledgeable.

The controller depicted is the Coleman Air C150-SMA. This is a solid state PWM controller, well suited for both wind and solar. The C150-SMA controller is capable of running in battery based systems of 12, 24 or 48 volts. Please check the specification of your controller before installing it.

The turbine is mounted on a pole, preferably 30' or higher above the tallest object that is within 100 feet (300' is preferred) from the turbine. The three wires are normally routed through the inside of the pole. Most turbines do not require slip rings as the turbine will go one direction about as much as it goes the other. Often a #12 gauge outdoor extension cord is used from the turbine to the ground, as these cords are quite flexible and durable.

Be sure to ground your turbine and pole using a copper ground rod hammered deep into moist earth. Failure to properly ground your turbine WILL almost certainly result in equipment loss due to lighting and static discharges.

The 3 phase wiring can be smaller than the D/C wiring as each wire only carries 66% of the total current being generated by the turbine. On the D/C side, each wire (two wires) carries 100% of the total current (What comes in, must go out.) See our wire size calculator for more information about wire size.

Inside the battery/controller room, the turbine is connected to a 3 phase disconnect/brake. This allows the turbine to be disconnected from the rectifier/battery by simply flipping a switch. In the full down position, the 3 phases (wires) of the turbine are shorted together, causing a large load to be placed on the turbine, significantly restricting it from spinning in most winds. In very high winds, the turbine may overcome this short circuit load and spin (perhaps quite fast), even with a full brake applied. It is not recommended to apply the short circuit brake during a high wind event unless the brake can be applied during a low. The best way to know when the winds are a bit lower is to incorporate a amp meter in your system (as shown.) The brake should always be applied before you service the turbine. In addition, tying or otherwise restricting blade movement during turbine installation/service is essential to safety. A spinning turbine blade can slice though a skull like a knife though butter -- be safe!!

Leaving the turbine/disconnect switch, the 3 wires are routed and terminated to the 3 phase input of a suitable 3 phase rectifier. The 3 phase rectifier depicted above is the Coleman Air - R150 rectifier, your system may not require such a large rectifier. Smaller rectifiers are readily available as well. The 3 phase rectifier, rectifies (converts) the pulsing A/C (alternating current) into D/C (direct current). The D/C output voltage (of the rectifier) will be 1.3 times higher than the RMS A/C that is entering the rectifier. For example, if you measure the incoming A/C voltage on any two A/C wires, and your meter reads 18 volts A/C, then you can expect to see about 23.4 volts D/C leaving the rectifier (on the D/C terminals). A rectifier does not downshift or up-shift the voltage. The 1.3 times is simply because you have three current carrying wires coming in, verses two leaving. There are other factors including the conversion from RMS (root mean square), but to keep it simple, 1.3 times any incoming pair will equal the D/C out.

Leaving the rectifier, the D/C current is routed though a shunt resistor for the matching amp meter. A shunt resistor causes a very SMALL voltage drop which is directly proportional to the current flowing though it. This small voltage drop is measured by the amp meter. Thus the amp meter displays the current flowing through the shunt (which of course is the current from the turbine to the battery bank). Analog amp meters are are also a valid choice and can be more economical. Dual voltage/amperage meters can be used as well if your controller does not have a voltage meter. An amp meter is not required but not having one really puts you in the dark when it comes to knowing how your turbine is performing. Also, as mentioned above, applying a brake in very high winds can actually destroy the turbine, so an amp meter can be used to know when to apply a brake.

About Breakers: Leaving the shunt, we route our positive wire to a breaker or fuse. The purpose of this fuse is not really to protect the battery (or anything else) from the turbine, but to protect everything (including the battery) from the battery. Batteries are capable of supplying massive amounts of current (in excess of 900 amps!) that can weld metal, start fires and given the right conditions, electrocute people. Basically, anytime you run a wire from the positive post of the battery it should go though a breaker or fuse. The fuse should be rated higher than the anticipated current that the leg will handle. If your turbine is capable of producing 50 amps in the best of conditions, then you might consider an 80 amp breaker or fuse. This ensures that the breaker will never trip due to normal currents from the turbine, but only trip if something really wrong has occurred (like you accidentally touch the positive wire to a ground.) -- If you are installing your system based on local/state codes, you almost certainly will be required to have breakers and disconnects in your system. Not having them is REALLY REALLY DANGEROUS!

Note: The Coleman Air - C150-SMA does have an internally mounted battery breaker, yet we have shown an additional externally mounted breaker between the battery and controller, why?. Even though this controller has a battery breaker, it is really better to have an externally mounted breaker as well, for safety reasons. The internal breaker does provide protection to the controller, but not to an operator that may be servicing the controller, as the "hot" wires coming into the controller will remain "hot", even if this breaker is off. Many installation codes require a breaker to be accessible without having to open up an enclosure where the operator can contact any current carrying wires or busses. A small breaker box (sold at the hardware store) can be a really handy item when you have multiple wires leaving your battery bank. Wiring your battery to the top of the breaker box, you then run your turbine to a breaker, your controller to a breaker, your inverter to a breaker, etc. Please note there are differences in D/C current Vs A/C current when it comes to breakers. The use of an A/C breaker box may not pass mustard with your inspector. You can Google this subject for more information.

The breakers depicted above have both automatic and manual disconnects along with manual resets. This allows the breaker to be used as a switch, in addition to providing over-current protection. Please check your code restrictions on using a breaker as a switch.

Leaving the breaker, we finally arrive at the battery, where the turbine's energy charges the battery (as long as the turbine's voltage is higher than the battery voltage of course.)

See our FAQ's about turbine voltages and currents.


The Controller:The basic operating philosophy of a diversion controller is quite simple. Monitor the battery voltage, and if it should rise to a predetermined level, connect a diversion load or "Dummy Load", of sufficient size, to the battery or energy source to prevent the battery voltage from increasing any further. This is a very simple, yet very effective way of preventing battery overcharging. See the discussion on controllers for more information.

The Diversion Load: The Diversion load or real world load is routed to the controller via a breaker or fuse. Again, this fuse should be sized larger than the amperage you expect the diversion load (or working load) will draw on a normal basis. If you have a 60 amp load, then a 80 amp breaker should be fine.

Diversion controllers work by diverting excess energy from the wind turbine to a diversion or "dummy load". This diversion allows the turbine to remain under a load at all times. A solar panel may be safely disconnected from the batteries, but an active wind turbine should never be disconnected from its load (battery/diversion load). When a wind turbine is not loaded, it can easily speed out of control in high wind events, which can lead to catastrophic failure of the turbine as well as the possibility of damage and injury to other property and people. It is very important that your turbine has a very reliable load at all times. Please see the full discussion on diversion loads.

That's pretty much it. Your inverter (if you have one), will hookup to your batteries (via a breaker or fuse of course). The charge controller does not control the inverter, and the inverter does not control the charge controller. The size of the charge controller is not conditioned upon the size of the inverter and visa-versa. They are independent in the sense they both do their own thing. The diversion controller's job is to prevent battery overcharge, and maintain a proper battery voltage to extend the life of the batteries. The inverters job is to convert the stored D/C energy into A/C energy that can be used to power household items or if you elect to purchase a grid-tied inverter, slow your meter down (or run it backwards). But that is a topic for another day.

Three phase wind turbines are by far the most popular stator (the inside of the motor/alternator) design used by the larger turbine manufactures, and increasingly by the smaller turbine vendors. They can be very efficient, can be very long lasting (no brushes), can offer very good current handling both in and outside of the stator due to the 3 wires Vs 2 wires.) Given a choice between a three phase system and a single phase A/C or D/C system, the 3 phase system should hold the advantage, all other things being equal of course.


Enjoy your projects, stay safe!! Turbines can turn into growling monsters, take the time to do it right!


Click here for the same diagram using the Coleman Air C160/C160M controller. (Page 6.5)

Click here for a dual solar/wind diagram using the Coleman Air C440-HVM controller. (Page 7)

But I have a single phase (or D/C) Turbine -- Click here. (Page 6.75)

See our FAQ's for lots of great information.

Available manuals for each product we sell can be downloaded from the product's detail page.