Expanding

Re: Expanding

I moved your posts into one thread in the Wind section...

Here are some bus bars (scroll down) and a shunt connection expander from Midnite Solar.

And some more bus bars from Outback.

The non-insulated are generally used for safety ground connections in metal box. The insulated are used for powered connections.

The above are bars with lots of random holes (from 14 awg to 0 awg). Mount them close to the battery bank--run one heavy gauge cable from the battery bank +/- to the plus and minus bus bars. Make all of your electrical connections from the bus bars.

Remember fusing--Each wire leaving a bus bar shall go through a fuse/breaker sized for the gauge of wiring leaving the bus bar to reduce the chance of a short circuit causing fires. Normally, only the positive lead is fused/breaker. Negative/Return/Safety grounds are not fused.

Fuses are a "cheap solution" but you may need a switch to turn off power (like to an inverter). Circuit breakers are nice because they can also be used as a switch--but are quite expensive.

Our Host's Wiring/Protection Main Page
Midnite Solar System Installation Product (more wiring/protection products)
OutBack Power - Fuses And Breakers (even more wiring/protection products)

More questions?

-Bill

Re: Expanding

In general--Solar and Wind use two different types of regulation. (note: all generalizations are wrong--including this one).

Solar panels can be turned on and off without any damage. So the solar charge controllers are connected between the panels and the battery bank (not including fuses/breakers, which is a whole issue itself):

solar panels -> charge controller -> battery bank

Wind turbines typically require a load 100% of the time, or if you Turn off their power (open a switch) -- two things happen.

1. output voltage goes way up--could damage electrical components
2. no-load on wind turbine allows strong winds to cause turbine to over-speed and self destruct

#1 is possible with some wind turbines with internal electronics... #2 is a problem for all horizontal axis wind turbines (HAWT)--No load on the turbine will cause the turbine to over-speed and toss blades, ruin bearings, collapse tower, etc.

So--the typical wind turbine is connected to the load (battery bank) 100% of the time. As the wind increases, the charging current / power keeps the blades spinning within the safe range.

But, in times of high wind and light loads, the battery can overcharge. So, a "shunt" controller connects to the battery and turns on when the battery is full--dumping the excess energy to an electric heater of some sort:

Wind turbine -> battery bank -> shunt regulator -> resistor bank

Note that in this case, if the shunt regulator or resistor bank fails--you can have dangerous over charging of the battery bank... So, the US national electrical code (NEC) requires that two independent shunt regulators/load banks be used -- in case one fails, the other will still function correctly. If your battery bank is not in your home/place where a battery failure can cause problems--you could pass on the second shunt regulator.

Note that there is a common method of "turning off" the output of a wind turbine... Basically, disconnect from the battery bank (switch or blocking diode) then short the +/- output of the turbine. Since Power=Voltage*Current where voltage equals Zero Volts, there is no heat/load bank required to limit the speed of the turbine (used for maintenance or in stormy weather).

However, there is heat generated when a wind turbine is shorted--it is generated in the windings of the wind turbine's alternator/generator--this has been known to cause overheating/failure inside the wind turbine. So, as always, review the manual for proper setup of the turbine's electrical system.

Now--to confuse things even more--People are designing MPPT (maximum power point tracking) charge controllers for wind turbines that connect like a solar charge controller does (between wind turbine and battery bank) to increase the power generations from the turbine--I have not seen the details of the setup yet--so I do not know how they handle the excess energy (direct attached loads, short the wind turbine output which slows a turbine way down, or whatever)....

So--it goes back to reading the manual for the wind turbine/charge controller setup you have. Generic answers are helpful to learn the terms and the various ways of setting things up--but may not apply directly to your particular brand/model/setup.

I hope I made things clearer rather than more confusing... :roll:

-Bill

Re: Expanding

I should add--the electrical wiring/connection between the charge controller and the battery is critical for proper charging of your bank.

Virtually all charge controllers measure the battery voltage through the heavy wires from the charge controller to the battery bank.

If the wires are too small, too long, or are shared connections with other heavy current devices (other charge controllers, inverters, other loads, etc.), you can get an error voltage (voltage drop or rise) in the wiring to the charge controller and it can misread the battery voltage.

Battery voltage should be controlled to better than 0.1 volts---If not--then you will have problems charging the battery bank (typically either will not fully charge the battery bank, or will take much longer to charge fully).

That is why we suggest making all connections back at the battery bank/common bus bar point (very heavy cable from battery to bus bars). That way, you will have very little voltage error back to the charge controllers.

-Bill