Setting up EG4 6000ex in parallel

[Dralkyr]

I'm starting to regret my purchase after watching Will's review, but at this point it is what it is. We are off-grid and living in our rv trailer while we build our house. I purchased the 6000ex instead of the 6500 expecting that I could use a single one to power everything and then bought a second one as backup in case the first one went down. The only thing we actually need 240 for right now is our well pump which is only run for a few hours at a time once or twice a week. Unfortunately, though, a single RV A/C unit jumps the output capacity over 75%! We have a second trailer here and visitors coming soon to help work with us and I'm sure they'll want the A/C on in that trailer, too. Even turning on the microwave, blender, or toaster while the A/C is on can flip it out. I guess I should have just gone with 2 6500s.

But now this is our situation.

So in order to power the second A/C unit without killing everything I think I need to set up what was supposed to be the backup inverter. For someone who's never dealt with solar or anything much electrical, though, I'm having a really hard time figuring out how to put the second inverter up. I've read the manual, I've watched videos, but I'm still lost. Do I have to have the batteries connected to both inverters or can I just have them going to one? If both: I have 4/0 cable running from my batteries to my first inverter - do I need to also use 4/0 cable going to the second?

I'm sorry, I'm just frustrated with the system and confused about what to do.

 

[sunshine_eggo]

Do you have microair soft starters on your A/C? Most RV A/C run about 1500W continuous, but their surge can be brutal - 5X that. Microair soft starters significantly reduce the startup surge.

 

[Dralkyr]

Do you have microair soft starters on your A/C? Most RV A/C run about 1500W continuous, but their surge can be brutal - 5X that. Microair soft starters significantly reduce the startup surge.

I don't. But the 75% is showing while running, not just at startup

 

[sunshine_eggo]

I don't. But the 75% is showing while running, not just at startup

That's pretty horrifying. That implies it's burning 0.75 * 6500 = 4875W?

If so, that's about what my 5 ton unit at home uses.

 

[BentleyJ]

If the well pump is the only 240V load then the RV A/C is 120V? The 75% load value may be based on a capacity percentage for that leg only. So the calculation would be 3000W x 0.75 = 2,250W which would be closer to the expected consumption for a roof top RV A/C.

Theoretically, if the 2nd AC was connected to the other leg and neutral you could run both units at the same time. Soft starters would be essential at that point.

 

[Quattrohead]

Yes just connect the 2nd inverter to the battery bank and it's loads.

 

[sunshine_eggo]

If the well pump is the only 240V load then the RV A/C is 120V? The 75% load value may be based on a capacity percentage for that leg only. So the calculation would be 3000W x 0.75 = 2,250W which would be closer to the expected consumption for a roof top RV A/C.

Theoretically, if the 2nd AC was connected to the other leg and neutral you could run both units at the same time. Soft starters would be essential at that point.

I totally overlooked that... very good points.

 

[Dralkyr]

If the well pump is the only 240V load then the RV A/C is 120V? The 75% load value may be based on a capacity percentage for that leg only. So the calculation would be 3000W x 0.75 = 2,250W which would be closer to the expected consumption for a roof top RV A/C.

Theoretically, if the 2nd AC was connected to the other leg and neutral you could run both units at the same time. Soft starters would be essential at that point.

Oooh I love that idea! So have trailer 1 out of breaker 1 connected to L1 from the inverter, then trailer 2 out of breaker 2 connected to L2 from the inverter?