PowMr 5000W Solar Inverter - not getting VAC out. Parallel setup for 240VAC single phase output.

[K-fab]

I've two PowMr 5000W inverters set up to run 240VAC (120VAC from each unit) to power an HVAC compressor.

Everything is wired correctly - I figure this to be a true statement as a very good friend (the guy who got me down this Solar rabbit hole and knows his stuff) gave it a look over and the "OkeeDokee". Plus I've not let any smoke out of anything when I've powered the system up. I'm decently sharp with this stuff and REALLY respect electricity. Being shocked is my #1 most despised 'input'.

All lugs/connections are tight, as Will says that most of the systems he troubleshoots have loose connections. See? I pay attention and I'm trainable!

I'm in contact with PowMr's tech service right now but I figured I'd toss this out on the forum and see if anyone can find (what I imagine will be a really simple fix) the issue. Below is what I shared with PowMr's tech after they asked for more info.


Pictures are of:
Entire system
Inverters, BMC, breakers/cut offs
Unit 1 wiring
Unit 2 wiring
Unit 2 fault
Unit 2 VAC in from breaker. This is the same voltage as Unit 1 but from the other leg of the breaker.

I cannot get any VAC out of either inverter.

No. 1 is set to AC1st because I’m trying to pass 120VAC through. This will get set to PV1ST when issue is solved.

Many of the voltages listed are what came up on screen as I scrolled through the settings. I’m guessing this is set by the inverter because of battery selection? LiFePO4 is what I have. Bank of 16 EVE LF304Ah Grade A batteries.

No. 30 - I have one unit set to address 1 and the other to address 2

Code - Unit 2 is reporting Fault Code 39 - ParaAcSrcDiff Inconsistent AC input source in parallel. I’m taking the input 120VAC from the same double pole circuit breaker. One leg leads to Unit 1 and the other leads to Unit 2 (the problematic one).
All grounds and neutrals feed to the ground and neutral bus bars in the breaker box on the other side of the wall from the inverters.
All of the wires are about a meter long from breaker panel to inverter.

Both inverters have these settings:

No Setting
1 AC1ST
2 60hz (default)
3 UPS (default)
4 42.8V
5 50.0V
6 PV1ST
7 100A
8 LFP14 <---- THIS IS WRONG. It should be LFP16 since I'm running a 16S/48V battery. It also changes the default voltages accordingly.
9 CU49.2
10 120min Default
11 49.2V
12 42.0V
13 5s (default)
14 44V (default)
15 40.8V
22 DIS (default)
23 ENA (default)
24 ENA (default)
25 ENA (default)
26 ENA (default)
27 ENA (default)
28 40A (default)
30 id1 & id2 (two units Unit 2 is throwing the fault) <----- You need both of the communication cables installed between the units.
31 2P1 <---- Nope! It's PAL This and dual communication cables let the units shake hands and swing sine waves in synchronicity.
Line 31 is INCORRECT - my orange note was editing after getting things working temporarily. See my last entry (#6 in this thread) for the correct settings. One unit needs to be 2P0 and the other 2P2.
32 SLA (default)
33 WOW
34 DIS (default)
35 46.0V
36 100A
37 48.8V
38 120Vac (default)

I did not include any of the timer settings as I'm not using them nor have I changed any from default.

Edits to this original post are in color.

 

[42OhmsPA]

Is your manual the same as this?

My interpretation is you'd want setting 31 set to 2P2 on the second inverter, 2P0 on the first.

 

[K-fab]

I'll give that a shot. Thank you.

 

[K-fab]

Well, all that did was make Unit 1 throw fault code 39 and Unit 2 is now quiet.
Still not getting VAC out.

 

[K-fab]

More research on phrasings and meanings and now I understand single phase and split phase.

The inverters need to both run in single phase, parallel connection. This keeps the sine wave output in sync. If they were 180 off, you'd have no voltage.

Selected option 31 on Unit 2, selected PAL and exited menu. Go to Unit 1 and it's already set. I had PO2 selected. They must automatically program certain setting on both units via the parallel ports. Just a guess, though...

Heard a click and the display shows that it's outputting from the grid through to 120VAC out. YAY! Quick test with the meter verifies I have output. YAY again.

I went into the menu again; Option 1 and set it on PV1ST. I hear another click from the two inverters and the display shows power from PV to inverter and then out to AC and battery.

IT WORKS!!!!

Man it's satisfying to complete a project. Especially when it throws a few curve balls at ya. It made me understand the system better.

Now I have to get my Daly BMS to talk to the house wifi and I'll be golden.

 

[K-fab]

Is your manual the same as this?
View attachment 238949
My interpretation is you'd want setting 31 set to 2P2 on the second inverter, 2P0 on the first.

An update. My last post said stuff was working - well... worked for a moment or two.

I've still been fighting with this phase issue for the past week or so. Setting both of the units to PAL seemed to work for a couple of days and then Unit 2 started throwing codes again and went off line. In fact, Unit 2 started a cycle of providing an AC output that started at 120V and then dropped to 98V then the unit shut down after 5 seconds of this. It would reset after a 60 seconds and then repeat the output, trickle down, shut down.

I knew the key was the phase but wasn't sure where - input maybe?
I tried putting both inverter input feeds on the same leg from the breaker (hoping that would put both on the same phase) - nope.
I removed all load from the inverter and played around with settings again. Could get 120V out of Unit 1 but nothing out of Unit 2.
Switched the leads from the breaker to the inverters wondering if that might be an issue - nope.

I left the units on overnight, letting the one cycle through it's 65 second run. The next morning I head back to mess with it and both units are running and showing 120V output but there still Code 39 flashing on unit 2.

A quick test with the volt meter verified that each unit was putting out 120VAC but testing across the two output legs, instead of getting the desired 240VAC I was getting a few millivolts. This told me that my phasing was incorrect - they were canceling each other out.

More reading and trying to comprehend what the manual states. I'd read over it a few dozen times but knew there was SOMETHING amiss.
I had been working off of this diagram idea:


Interesting - there's a Line and Neutral output shown. I need a pair of Lines out and no neutral.

More reading, inspecting and I come across this graphic:



Two lines out, L1 and L2, each from a single inverter and there at the top of the diagram is P1 and P2.
My pea brain's light bulb flickered. I might be onto something!

Went back into setting #31 and played with the suggested settings of 2P0 and 2P2 (the more I read the manual and the more I push buttons the more I'm understanding the system - when I first opened the manual I was reading stuff that made absolutely NO sense).

As I toggle through the selections in Setting 31 a little L1 and L2 shows up on the displays next to the graphic showing power coming from the grid to the load. Hmmmm... yeah, something's in order.

If I set Unit 1 on 2P0 and Unit two on 2P2 I still get a phase error but when I switched them all of a sudden the error light disappeared, things started happening and I now have 240VAC out between the two units. You were correct on your comment, it just didn't work the first time for some reason.

Both units are up and running and now my HVAC system is off grid and cooling away.
I walked around the house with my chest proudly puffed up for a couple of hours after getting it all dialed in.

Solar's fun, they said...
It is when it works.

Now I just have to get my Daly BMS to talk to WiFi (does with Bluetooth but I need more range) and I'll be fully set up. I'm in touch with their service dept.

 

[42OhmsPA]

The manuals could should be a lot better written.