Inverter

[Iceni John]

As Tom said, you'll need (a lot) more batteries to power a 3kW inverter!   3kW at a nominal 12V is a whopping 250A  -  that's almost at starter motor current levels!   The generally-accepted wisdom on the Northern Arizona Wind & Sun solar forum is that drawing more than about 100A from 12V batteries will run you into Mr.Peukert and his limitations on battery currents, unless you have a battery bank a lot larger than your two Group 31s.

To put this into perspective, I have 2kW of solar panels that will charge eight golfcart and/or L16 batteries through two Morningstar TS-MPPT-60 charge controllers.   Even with a minimum of 900Ah from eight GC-2s (or more if I use L16s), I don't plan on having a TSW inverter larger than 1500W for general AC loads.   I will also use 4/0 cables from each bank of four batteries to their isolator and from the two isolators to the main DC load center  -  for a 3kW inverter running off 12V I would suggest paired 4/0 cables to minimize voltage loss.

Back to the original question.   Assuming your inverter is about 90% efficient, you could be dissipating up to 300W of heat from it at full load!   That needs some serious thought about airflow and heatsink orientation.   For that much potential heat production I would mount the inverter on perforated 1/4" aluminum sheet  -  definitely no wood anywhere near it!

John

[Beesme]

If I were to use 3 k yes I agree. I just got a good price on it . The only power that will be going through it is a refrig that most of the time is only at a couple hundred watts even start up is only around 1 k and that is at start up. I don't know very many peeps using  3 k unless you were using ac I guess . This is for keeping beer and food cold . Nothing but fridg and 2 lights tied in.

[pvcces]

Idle current is significant in any low cost new inverter. You might be able to get the specs from the maker.

Good luck.

Tom Caffrey

[Beesme]

I am designing a cradle so inverter can suspend from ceiling upright . But just for info I have been monitoring temps of mounts and staying at 87deg. But for safety reasons I will move . Thanx for all the input.

[Beesme]

Sorry eagle 19952 . Yes inverter is something like that .

[mung]

So you don't want your inverter to be inverted?   

[Beesme]

Lol mung no I guess not inverted haha omg made me chuckle!