Yes I backfed my 15Kw 48v inverter and let out the magic smoke......

Yeah, you'd release the magic smoke for sure thataway....FYI almost certainly would release the smoke out of a GS inverter as well.

Can you clarify what you mean by "starts to flicker output"?  Is this a "shimmer" (actually pretty standard with PJ inverters across the board), or is it more of a strobe light effect (i.e. looking more like catastrophic failure)?

26 minutes ago, CrazyDave said:

Unit powers up with correct voltage.

Good to know.  (Am assuming this is "correct output voltage.")  It's next to impossible to damage the voltage feedback circuitry due to the extremely high impedance.

26 minutes ago, CrazyDave said:

Can apply load until 3-4 amps per leg. Any more it starts beeping/flashing red like it is over loaded and starts to flicker output.

Are there any visibly damaged parts on the output board (mounted behind the LCD display--if equipped), particularly around the SMT "DIP switch"?  (SW1, ADJUST1, ADJUST2, ADJUST3, ADJUST4.)  These determine the maximum inverter load / charge current. 

A remote possibility would be that the E135-LF-L transformer could be damaged, but this would be extremely unlikely. 

7 minutes ago, Sid Genetry Solar said:

Can you clarify what you mean by "starts to flicker output"?  Is this a "shimmer" (actually pretty standard with PJ inverters across the board), or is it more of a strobe light effect (i.e. looking more like catastrophic failure)?

It slow strobes I would say. Like it wants to shut down but does not. It may if I added more load. Did not want to damage more.

No noticeable damage anywhere on the output board.

Maybe the easiest/best thing is to just replace the control and output boards and be done with it? Got parts?

Thank you for the quick reply,

Dave

This is rather weird; the PJ CPU code does not have any proviso for any sort of glitchy regulation.

Backing up the smoke line...being a v9.0, the next potential culprits are the parts of the circuit that I would just as soon throw out entirely: It's possible that the "overload protect board" is faulty (the only one standing upright).  Gotta love the PJ design: it's a set of transistors and CMOS logic that shorts the CPU's FET drive outputs out.  (Not like the CPU has an instantaneous "/FAULT" shutdown input on it!)  This is the only part of the circuit that could cause a disco-ball output without causing a shutdown.  (Such really wild output stuff could potentially cause an alarm.)

The only reason smoke can backfeed up into the boards is because the LF Driver board is not fully isolated--and if you had a spectacular cloud of blown FETs, the smoke line probably continued up a little past the LF Driver.

Beyond this...kinda hard to say.  You'd have to contact @sean-genetry-solar for parts (Contact form / text message 833-GENETRY).

First Thank you for all your help. I replaced the "overload protect board" with one from another unit I have here. I will Attempt full load later today, but as of this time it appears to be working as it should.

I will be ordering backups to keep on hand.

Thanks again,

Dave

Glad to be of assistance.  Working on a new design control board for PJ...we'll see if they take it 😉.  I'll have to make it cheaper than their current iteration, that's for sure.  Did give them a new balanced LF Driver design which they're currently testing--it may be something Sean can have on hand as an upgrade.

Keep us posted as to how the inverter works.

Are you giving these designs to PJ for free?

Feeding the hand that feeds us...whether they do or not, we could not make GS inverters without them.  Once they have a working design, they'll pay something for it...but I don't really care how much.