EG4-6500 system starting 4 ton A/C

EJansen said:

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.

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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.

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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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SilverbackMP said:

I wonder how well the soft starts work with loads other than AC. I read that they aren’t ideal. Am thinking that I might use 3-phase motors and VFDs on anything over 4-5 hp. Biggest two would be an air compressor and dust collector. And possibly a European Joiner/Planner combo.

I have four Sunny Islands that should be able to handle a lot, but I don’t want to hammer them if I can avoid it.

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THERED117 said:

Do you have to pull the pump or will it wire in at the contacts?

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THERED117 said:

My soft starter should be here in the next ten days. Once I install it I'll give you some feed back on how it does.

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THERED117 said:

Got my soft starter in. Works like a dream. It pulls a hair more them my 1 hp well pump but less then my stove. Only hitting 30% on both inverters. Usually only at 6% for normal house. Lights, fans, and ect

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Solar Guppy said:

The squirrel cage motors in air handlers that are typically psc motors will have close to locked rotor amps when started can be an issue. In mine I replaced with a variable speed motor ( ecm ) with a controller to adjust airflow to my duct work and it's also setup to be two speed, low for 15 minutes and automatically goes to the second speed if demand requires more air flow

This is one that doesn't need a controller and is an ECM ( ramp up to speed over ~20 - 30 seconds ) and is very simple to hook up / replace as motor air handers use the same frame size for the motors. Here is the manual

Another benefit is ECM is very efficient where psc motors use a capacitor to slip the phase for difference speeds, all the same power draw just wastes energy.

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