new bigger problems

[greenkarson]

most of you probuly read my last post about my creek being dry and if I could charge my battery bank with my 12v generator.  Well anyways after posting that I  went up to my cabin for the weekend were everything is located and to my surprise there had been a big rain storm and the batteries were almost completly charged. so I turned on my inverter and nothing. No lights, nothing showing on the inverter's battery gauge and no ac power. so let me get a bit more technical

24. v 100w hydro turbine, 2 12v 255amp hour batteries wired for 24v. A c40 charge controller wired in dump control mode with a hot water element for a dump. aims corp 1500watt 24v inverter sinewave
    
2. weeks ago left tv on drained batteries down to 20v thats the shut down volts for my inverter the low voltage alarm was on so i turned the inverter off with its own switch.  The creek was very low and turbine was not spinning fast enough to charge batteries then so i left the inverter off and left for the weekend.  So last weekend went back to my system expecting batteries to still be around 20v because id shut off the inverter the only thing hooked to my batteries.  But the batteries were down to 17.5v so once again i just left every thing off with no way of charging the batteries with me(by the way this is a ATV only access cabin).so returning yesterday with generator to charge batteries like i mentioned earler batteries were back up to 23.4v with no power coming out of inverter. so i opened it up and noticed there are several 15amp fuses and one of them was blow so i replaced it with the proper fuse and turned the inverter back on and pooof actually burst into flames in to differnt spots with a third smoking all this within about the half a second that it took me to shut it off. I assuming that i just fried my 400$ inverter. But more conserned about what could have caused the problem to start with the inverter hook up to the batteries is pretty fool proof and the inverter worked fine for the first 3 weeks. or was there just a demon living in my inverter all along.
   
   

is there any hope of anybody being able to rebuild inverters or do i just start looking for another?

any ideas what caused it to blow the fuse the first time and not burst in flames then like it did when i replaced the fuse?

any info is good info

thanks Karson

[Flux]

As you were away you can only guess what was happening.

If you pulled a 24v battery down to 17v then it was dead flat and probably sufficiently sulphated for it to be reluctant to take much of a charge. If the floods came and your turbine kicked into life then the battery may have gone way up in volts until you removed enough sulphate for it to start taking a charge.

If your inverter was connected ( but switched off ) then it may have blown from over volts. Another possibility is that it may have already died and caused the fall in volts from 20 to 17 when you were away.

One thing is certain it is dead and unless you find someone whose hobby is fixing dead cheap inverters then it's a goner. The fuses protect your wiring, they never go unless the mosfets have been killed. Mosfets are generally killed by other circuit faults so changing fuses and mofets normally gives you another attempt at the smoke.

Without being there and seeing what was really happening you may never get to the root of the trouble.

Flux

[FishbonzWV]

I had the same tale a few years ago.

Remote farm...fried $500 inverter.

The inverter died a different way though.

One thing was, when I left the camp I always disconnected the batteries from the inverter. I had a 50w PV panel to keep the batteries up and if lightning were to strike I didn't want it taking out the inverter.

A pair of these made the connections easy

http://www.grainger.com/Grainger/items/3BY23

The replacement inverter was a cheapie and occasionally I would have to remove battery power to get it to reset, so these came in handy for that too.

Oh yeah, I now have a $500 metal enclosure for my Watgas battery charger. :-(

Bonz

[Ungrounded Lightning Rod]

I noticed several other connectors in the family with various wire sizes.

Do you know if the connectors all interconnect?  (Would make sense to have two fat ones for the batteries and the major load and one with smaller wire for a slow charger.)

[FishbonzWV]

No, they vary in size according to amp rating.

I have a UPS with dinky ones with 8 gage wire and the ones at camp were 1/0.

Fork lift batteries use some pretty good size ones, 4/0.

 

[freshair]

ULR,

Its a handy connector, and there are multible wire sizes available (interchangable/replaceable contacts) for each amp rated connector.

Common are

50. amp
    
125. amp
     
175. amp
     
350. amp
     
     

I'm using 50, and 175 amp connectors. The 50s have contacts for #12/10 - #6 wire. The 175s have contacts for #6 - 1/0. (Something I have found is they run a little large and sloppy... I'm using #6 wire in the #8, and #4 wire in the #6 contacts with ease.)

Gray is the most common color, but they actually are color coded for voltage.

Yellow = 12 volts

Red = 24 volts

Gray = 36 volts

The different colors "wont" plug into each other, even in the same amp/frame size.

You can find them on eBay cheap.

[freshair]

Not sure why it did that but it should have read 50 amp, 125 amp, 175 amp, and 350 amp.