Wiring Help Please

2Guido2Guido Solar Expert Posts: 62 ✭✭
Newbie....need help...have 2 low wind 12v PMA's charging a 12v bank of AGM's. They are currently wired in series with a blocking diode directly to the batteries, but I am wondering if they should be paralleled wired and can I eliminate the blocking diode to maximize charging current ???
Thanks

Comments

  • BB.BB. Super Moderators, Administrators Posts: 29,988 admin
    Re: Wiring Help Please

    Do you get any useful power/current from this configuration into your battery bank? If so, I guess leave it as is.

    If you parallel the 12 volt turbines onto a 24 volt battery bank, you probably will get pretty close to zero current except in hurricane type winds (OK, really 30-40 MPH winds).

    If you want to parallel two PMW alternators--There are two places to parallel. Once is the set of three wires from the Stators. This is the wrong place to parallel a pair of unsynchronized alternators. The phases and frequency of the alternators will not match and can cause some strange behavior (you could have one wind turbine driving the other wind turbine like a motor generator, etc.).

    The second place to parallel would be after the AC to DC rectifier... That is the place to parallel them together. However, if the turbines are designed for 12 volt battery bank charging, then they will output little to zero useful current when connected to a 24 volt battery bank except in at very high RPMs/Wind Speeds.

    Lastly, if you already have rectifiers in your pair of wind turbines, there should be no reason for a diode in the wiring to the battery bank unless you are looking for additional protection (diodes can fail open or shorted)--In any case, you should have a fuse/breaker there for protection too.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • 2Guido2Guido Solar Expert Posts: 62 ✭✭
    Re: Wiring Help Please

    Thanks for your help...just to clarify, this is a different system than my profile. The battery bank is 12volt. One of the PMA is three phase whereas the other is DC out of the PMA. Is is still ok to parallel them after the one pmas rectifier ???
  • BB.BB. Super Moderators, Administrators Posts: 29,988 admin
    Re: Wiring Help Please

    Sorry about the 12/24 volt battery confusion--I obviously did not read close enough (was remembering your first post asking for help--obviously wrong).

    Basically, connecting the turbines in series would not do much (if anything positive) to increase power to the battery.

    Paralleling the turbine output... Obviously, a three phase AC turbine cannot recharge a DC battery--there must be some sort of rectifier there.

    So, the correct point to parallel would be the DC output from one turbine (and its internal rectifier) to the DC output of the external rectifier of the second turbine (obviously, + to + and - to -). Then run the leads to the battery bank (you could connect the two leads at the battery bank buses too--whichever is easier to wire/fuse/breaker.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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