diy solar

diy solar

EG4-6500 system starting 4 ton A/C

PreppenWolf said:
Do you have enough battery to weather the voltage sag of the draw?
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I have 6 of the LifePower4 batteries. It's enough to power my 60 Amp Plasma cutter, but for some reason as soon as I turn on the breaker for the AC unit, it faults for some reason. There's only one way to wire it, so I'm not sure what's going on. If I flipped the phase wires in the breaker, it would go boom (ask me how I know) ;).

I should also note that I do have MicroAir soft start kits on both of my AC units, and just tried to cut over the smaller of the two.
 
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Adam De Lay said:
I know I have a 3.5 Ton and even if my inverters did run it, I would still put a soft start on it. Sounds like a summer project for me...
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If you do, definitely make a video of how you did it. :) I'm still trying to figure out why it didn't work for me.

Perhaps @RV10flyer can chime in, but as far as I know (but I'm an IT guy) an AC Unit doesn't care what phase its wires are on, as long as they're on opposite legs. Even still, I tried to keep everything lined up, from a phase perspective from the main panel to the sub panel that feeds the inverters to my off-grid panel that gets fed by my inverters, where Black is L1, and Red is L2. In doing so, when I cut the 10/2 that was coming from my main panel that feeds the AC unit, I just moved the black wire to phase 1 in my off-grid panel, and the white wire, that I added red tape to, to L2 in the off-grid panel. Same setup as in the main panel, just now in my off-grid panel. I then would flip dual pole 25A breaker on and the inverters would then fault for some reason.

Then I figure...well, if it doesn't matter (which maybe it does) which hot goes to which leg, since it's just sending power to a load, then why not try to swap the wires in the breaker. I figured; it wouldn't take long to test to see if I got the same results. I did in fact get different results though - a big pop/boom/arc flash between the panel and the wall when turning the breaker on. I'm still trying to figure out why that happened though. If I was trying to set up say 4 EG4 6500s and upon adding the second two, I accidentally connected the 2P2 from the second pair to the same leg as 2P1 on the first pair, then I get that - but I don't understand why it happened in my scenario.

If anyone has any ideas, please let me know.
 
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Sounds like you have a short in that AC cable. Maybe moving it around made it complete it's failure. Check around all junction points and the cable staples. Sometimes they dig in. I would start with the area between the panel and the wall where you heard the pop.
 
sollap said:
Sounds like you have a short in that AC cable. Maybe moving it around made it complete it's failure. Check around all junction points and the cable staples. Sometimes they dig in. I would start with the area between the panel and the wall where you heard the pop.
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Hmm, I spose I could disconnect it from the load and try it again. Worst case it chars the concrete backer board again :) - (joking - not doing that - I'll do a resistance test instead)

I'll get some pictures and share them a bit later today - it does sound like a short in the cable, but I couldn't find one; not to say it's not behind the outer sheath.
 
EJansen said:
After that though, I turned on the 25 amp breaker to power the AC unit, and the inverters immediately faulted for some reason. The error code was F52. Anyone have any idea why / what I may have done wrong?
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Clarify, are these connected to HVAC or you've cut the lines are are just turning on the breaker?

If the HVAC is there: Bet your HVAC has a big start up surge. There are "soft start" HVAC kits than can be used to buffer that surge.
 
dcg9381 said:
Clarify, are these connected to HVAC or you've cut the lines are are just turning on the breaker?

If the HVAC is there: Bet your HVAC has a big start up surge. There are "soft start" HVAC kits than can be used to buffer that surge.
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I just cut the line between the main panel and the HVAC to disconnect it, and then connected it to my off-grid panel, fed by the two inverters. I have MicroAir Easy Starts on my AC units though,
 
Here's a couple of pictures of the setup. In short, my main panel is in another room, so I had to run power to a sub panel, seen on the right next to the battery bank - which feeds the inverters, which feeds the off-grid panel to the left. That panel just feeds loads that I've added new, or moved over from the main panel.

1684259121448.png

A large bundle of cables come from the main panel to that area in the top left of the below picture - if moving a load, I just turn breaker off in the main panel, cut the wire, cap it, and then add it to a JBox that connects the load to the off-grid panel below. In this case, since this happened late last night and I had to move my AC unit back to the main panel, I just spliced it back together with WAGOs and taped it up temporarily until I can get it either put in its own Jbox, or back to the off-grid panel, spliced in a separate Jbox out of the picture.

1684259048643.png

The two orange cables are for moving the AC units off-grid. The one on the left is reserved for AC1, a bigger 4 ton unit that I just pre-ran the wire to the Jbox above where I'm standing and the one on the right is for AC2, a smaller 2.5 ton unit.

But as you can see by the burn mark on the concrete backer board, it definitely didn't like the hot leads to the load swapped for some reason - though it also didn't work the other way either. Either way, I figured I could at least put this out there for others to learn from once I figure it out.
 
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Quattrohead said:
Check all of your appliances in the home, maybe something else has stopped working too LOL
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All is well everywhere else. I only have a few things 'off-grid' - this is more of an expensive experiment for non-essential loads. Even if the inverters took a dump, I could just plug everything else back into other circuits that are still connected to the main panel, or move them back to the main panel - it'd just be a pain in the ass.
 
That orange wire on the right above your load panel - check the individual wires and outer insulation at about the point where the connector was attached. I'm surprised it's not more obvious on the cable, but that mark on the wall indicates that's where the short was.
 
sollap said:
That orange wire on the right above your load panel - check the individual wires and outer insulation at about the point where the connector was attached. I'm surprised it's not more obvious on the cable, but that mark on the wall indicates that's where the short was.
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Yeah, I took a look at it and did a resistance check between the white / black, white / ground, and black / ground - no connectivity at all...however, it's disconnected from the load / not the same setup as it was last night. Granted, it works fine connected back to the main panel and if there was a short further down the line near the load, then it would be apparent and wouldn't work when connected back to how it was.

Also, when it did happen, I thought it was on the wire as well, but the arc looked like it was behind the panel where it screwed to the cement board. It was close to the wire though.

I suppose I could swap the wire out and re-test - just hesitant to try that at the moment after the existing wire passed connectivity tests.
 
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I wonder it the wires got nicked during stripping and they're being shorted by the connector. I'm baffled why the wire and connector are clean, that's a significant mark on the wall. Regardless of what's downstream, there is something wrong with that cable right where that mark is.
 
sollap said:
I wonder it the wires got nicked during stripping and they're being shorted by the connector. I'm baffled why the wire and connector are clean, that's a significant mark on the wall. Regardless of what's downstream, there is something wrong with that cable right where that mark is.
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Yea, definitely going to take the cable down for further inspection - if I find anything of interest, I'll post pics.
 
Welp, sure enough after inspecting things a little closer while on the ladder, I found this:

1684271496742.png

it kinda blended in from down below, but as I peel the onion back further, it becomes more apparent:


1684271639532.png

1684271692575.png


With that said, I'll replace the cable, and try again tonight.

1684272035708.gif
 
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EPicTony said:
Has anyone used EG4-6500 (split phase) successfully to run whole house A/C ? My 240vac well pump starts and runs just fine.
I'm wondering if it will also do the same for my 4ton A/C unit. I know there are soft start modules for about $400 but I really don't want to spend any more $$$ if I don't have to.
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Look at signaturesolar.com. I just bought the 5-7 ton soft starter to run my ac. Mine is a 4 ton and lock rotor is like 110 amps. I think it was $260 tax, shipping ,and all.
 
I was was looking at a soft start for my 2.5 ton A/C last year. I found a company called Ametherm that makes NTC thermistors that are designed to lower inrush current. NTC = negative temperature coefficient. Sent the nameplate data to them and they sent me 2 to try for free. Only need one and it is working fine. Digi-Key also sells them. Even if you had to buy, they're much cheaper than a soft start kit. They sent me an MS35 3R725. I put different model # on my well pump this spring.
 
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