Hi, just wondering if this setup in regard to teh Midnite aux outpits will work ok. Diagram attached.
I've decided it's best to not use my WizBang Jr and use the aux 2 PWM output to control the dump load from the battery bank.
This was due to information I read here: http://solarhomestead.com/dump-loads-for-solar-wind-and-microhydro/
which sounded correct. Before this I was going to use a voltage controller and SEA-440 contactor.
Any advice would be great.
Cheers,
Is that contactor the Coleman Air mechanical type? Thats not going to work too well, if at all, with a the not-too-low-frequency
AUX1 or 2 PWM signalling from the Classic, or is AUX1 just going to on/off control?
PWM is really more suited to an SSR (Solid State Relay) such as those from Teledyne or Crydom.
Assuming the 1Kw turbine is the SOMA then a much better solution would be another Classic controller to deal with the SOMA
and use it to PWM an SSR that diverts the DC from the SOMA to a dumnp load resistor BEFORE the Classic.
Of course he best solution would be a Midnite Clipper although the combined Classic/Clipper would probably cost as much as
the SOMA.
dgd
Hi, thanks for your comments. Yes it is the Coleman Air type that are on EBay, It's controlled from Aux 1 which I don't think is a PWM signal. Just on/off depending on bank voltage. I will probably need a 12 volt relay in there to drive the coil.
The water heating relay is a Crydom SSR as it's driven from Aux 2 which is PWM. A second Classic or Clipper is out of my budget. I could use a second SSR instead of the mechanical contactor but not sure of the reliability off SSR compared with the mechanical contactors.
Cheers,
Ok, I though that was the type.
What I would be concerned with is that AUX1 will switch the relay without any problem but I doubt very much the air contactors
will survive too much switching if the SOMA is producing some real power. It can easily get to 1kw in a good wind and suddenly
switching from the battery load over to a resistor dump will risk a serious DC arc over those mechanical contacts.
Its a low cost relay and although it claims to be heavy duty (well 440 watts anyway) its probably ok for playing about with those advertised high output but really very low output type wind generators (MWANDS etc.), I would say it completely unsuitable for a decent generator such as the SOMA
This will not be an issue with a good SSR, a fet DC type, but these are not cheap (see the Teledyne types from Midnite)
I would also recommend not using AUX2 for PWM SSR control of an inverter, I think thats what you are attempting, the inverter will not respond well to that and I doubt its designed for that type of (ab)use but I may have misunderstood what you are trying to achieve and also your inverter may be able to do this.
The AUX2 PWMing a decent DC SSR which is introducing a dump load resistor bank into the output of the SOMA is what I would do but then I would also NOT consider connecting the SOMA directly to the battery bank either.
I cannot see any low cost solution to this and considering your investment in a decent wind generator and battery bank I would still seriously recommend you need to get another Classic in there to deal with the SOMA and also at least a good DC SSR if a Clipper is not affordable.
The setup you descibe would be ok for a small wind generator, a couple of hundred watts or so max power but not with the SOMA. I would hate to think what would happen if that cheap mechanical relay welded its contacts as there could be a serious fire risk.
Just IMHO
dgd
Hi, good information there thanks.
I will forget about the contactor and go for another SSR. I bought my Crydom one from Digikey. It was a couple of hundreds from memory.
The Inverter is straight off the battery. The relay shown is just to stop the water heating if the inverter is running as the fridge and freezer takes precedence. I'll also check the Soma control box which is up at our farm. I was just going to use the rectifier and dump resister. I'll see what it uses to divert to dump resistor.
Thanks,
Looking at the prices about, I could stretch to a Morningstar TS-60 as a diverter controller for the wind generator but I have seen the generator sitting at 50A now and again in a gust so it might be cutting it a bit fine. By the way, I bought the Soma second hand, I think they are around $6000 new so wouldn't normally have bought one otherwise. I'm stuck with the Midnite and the inverter but I was hoping to keep away from further electronics.
No, I just read the TS-60 dumps from the battery bank and the wind generator can stay connected. Might be a good thing. Will read further.