Power Inverter Transformer design discussion

Sid, the solution is for you to go to an oil cooled unit with a radiator on top. That way you could heat your home when its cold out.😉

And I have to agree with dickson, why use two different size wires on the output?

Sid, the solution is for you to go to an oil cooled unit with a radiator on top.

Mineral oil to cool transformer  works as someone on this forum  show .  Two  different youtube videos  show  how it done with oil cooling .   GS  inverter can not be sold as oil cooled  for liability issue  but DIY  after  warranty run out it can be done .   I  have to see Sean test the new 12kw transformer for cooling .  I  think 2kw will be loss to heat  so 14kw is needed  .  Ebay sell a new  tool to test in-rush  current of a heat pump surge  that last less than a second  and then  can be use to set the surge limit  of the transformer to shut down the invereter .   

Haha, funny.  Several people have suggested oil-cooled inverters--BUT oil does not intrinsically cool something.  It does, however, transfer heat far better than air--but at the end of the day, the same amount of heat must be dealt with one way or another.

PJ does not understand the American "split-phase" power system.  As far as they are concerned, the inverter outputs 2 voltages, "220v", and "110v."  Because the amperage at 110v is higher (for the same wattage) than 220v, they use more wire on the "110v phase."

Problem is, the USA "split-phase" power system is technically TWO series 110v phases totaling 220v--and ideally, the load will be distributed fairly evenly across the 2 phases.  GS inverter transformer specifications have both secondary windings with the same wire spec, for a balanced transformer.

Not a liability issue as much as an unneeded complexity/issue/challenge.  We're having enough entertainment getting custom chassis made to our exact requirements--much less an oil-tight sealed chamber design.

Mathematically, the losses in the transformer windings on the new 12kw tranny should be significantly under 10% loss.  I'm hoping to see ~700-800W heat loss at full load, with a total inverter efficiency >90%.  (Current test tranny inverter comes right in at 88%.)

PJ does not understand the American "split-phase" power system.  As far as they are concerned, the inverter outputs 2 voltages, "220v", and "110v."  Because the amperage at 110v is higher (for the same wattage) than 220v, they use more wire on the "110v phase.

Now I  know why  L1 has  more wires  because their engineer do not  know split phase  .   See the  pictures of my ASL9 transformer  as there is 2 red wires for L1  and one black wire for L2  .   That why  I  thought  PJ  do not have real engineer .   I  think PJ can not get  2 wires for L2  to go thru the center hole of the ASL9 transformer and the center hold down bolt has no room .    Thank you for all this transformer informations  as I  now know  why  the ASL9  overheat  and L1  and L2 is not balance .   I  will never use the ASL9  to run my 4 ton heat pump again .  It  took me  2 years  to finally  get this informations  after  blowing up  FETs and LF driver  and  mainboard and capacitor .    

Question: Are all PowerJack LF inverters wound with aluminum wire that is enameled? I noted that you indicated the 6k and 12k GS inverters have aluminum windings to save shipping weight (and i am sure cost), (all GS have aluminum wound transformers). that is why I ask.

Is it the iron core that makes (the LF inverter) them heavy?

I just bought a 3KVA step down transformer that weighs 75 pounds 240/480 primary to 120/240 secondary. $135 delivered (used from eBay) it is a sealed transformer.

I am thinking of running off the 240 volts coming out of the 15k or 20k split phase inverters and just going from 240 down to 120 by the external transformer.

the 3KVA external transformer is a heavy little brick for sure. still tinkering and learning about electrical things. thanks in advance for your help or directions.

Yes.

You bet.

All PJ trannies are aluminum-wound.  PJ's goal is to make the most budget inverter possible--and with aluminum being 1/3rd the cost of copper, something like 40% of the weight...it's a win-win.

Back before PJ was winding their own transformers, they were copper wound.  (These transformers can be identified by the colored/insulated wire coming out of the transformers, instead of the enameled strands going directly to the crimps.)  Such transformers used much thinner copper wire--so they aren't "collectibles" by any means.

That'll work, yes...but don't expect any significant increase in usable power output from the PJ inverter.  Not only have you added the external transformer's losses (i.e. PJ inverter has to run HARDER to power the same load, to make up for the external transformer losses), you've also put more load on the "thinner" PJ transformer winding (as now ALL loads will pull across both secondary windings).  It's worth a try, though...