Author Topic: Inverter  (Read 4789 times)

Offline Iceni John

  • Hero Member
  • *****
  • Posts: 1841
Re: Inverter
« Reply #15 on: September 02, 2014, 03:09:18 PM »
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
« Last Edit: September 02, 2014, 03:51:06 PM by Iceni John »
1990 Crown 2R-40N-552 (the Super II):  6V92TAC / DDEC II / Jake,  HT740.     Hecho en Chino.
2kW of tiltable solar.
Behind the Orange Curtain, SoCal.

Offline Beesme

  • 62 pd 4106 8v71 86 Newell classic wide body 8v92 turbo
  • Full Member
  • ***
  • Posts: 192
  • 1962 pd4106 86 newell
Re: Inverter
« Reply #16 on: September 02, 2014, 03:17:15 PM »
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.
Bruce E.                                                                        62 pd4106 vs730.                   
Gonic N.H.

Offline pvcces

  • Hero Member
  • *****
  • Posts: 803
Re: Inverter
« Reply #17 on: September 03, 2014, 10:48:55 PM »
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
Tom Caffrey PD4106-2576
Suncatcher
Ketchikan, Alaska

Offline Beesme

  • 62 pd 4106 8v71 86 Newell classic wide body 8v92 turbo
  • Full Member
  • ***
  • Posts: 192
  • 1962 pd4106 86 newell
Re: Inverter
« Reply #18 on: September 04, 2014, 01:15:11 PM »
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.
Bruce E.                                                                        62 pd4106 vs730.                   
Gonic N.H.

Offline Beesme

  • 62 pd 4106 8v71 86 Newell classic wide body 8v92 turbo
  • Full Member
  • ***
  • Posts: 192
  • 1962 pd4106 86 newell
Re: Inverter
« Reply #19 on: September 04, 2014, 01:24:49 PM »
Sorry eagle 19952 . Yes inverter is something like that .
Bruce E.                                                                        62 pd4106 vs730.                   
Gonic N.H.

Offline mung

  • Hero Member
  • *****
  • Posts: 576
  • PD-4104-772
Re: Inverter
« Reply #20 on: September 04, 2014, 01:27:27 PM »
So you don't want your inverter to be inverted?   :P
Vern in Central Florida
PD-4104-772

Offline Beesme

  • 62 pd 4106 8v71 86 Newell classic wide body 8v92 turbo
  • Full Member
  • ***
  • Posts: 192
  • 1962 pd4106 86 newell
Re: Inverter
« Reply #21 on: September 05, 2014, 03:55:46 PM »
Lol mung no I guess not inverted haha omg made me chuckle!
Bruce E.                                                                        62 pd4106 vs730.                   
Gonic N.H.