Parallel EG4 Inverters: AC Output Length

[mossymeadow]

Hello DIY Solar friends

I have a set up with multiple (6) EG4 6000XP Off Grid inverters. Each inverter will run L1, L2, N, G to the main breaker panel, connected via a back-fed 2 pole 35A breaker.

The inverter closest to the main breaker panel is only 3 feet away. The furthest is 16 feet away.

Should all the inverters use 16 foot long AC output cables or is it OK for one to have 3 foot AC output cables, the next to have 5 foot cables, the next 8 foot.... etc until the final one has 16 foot long cables?

If unequal lengths are used, will the house draw more power from the 3 foot inverter than from the 16 foot one? Or, is the EG4 inverter firmware able to mitigate the unbalanced lengths and ensure even draw to all paralleled inverters?

I've had a hard time finding a clear answer and appreciate your insights!

 

[BentleyJ]

Since its only a 35A breaker, a good strategy would be to upsize the wiring to 6AWG so resistance becomes negligible.

Not sure it is necessary but if you really wanted to do an engineering project you could match the voltage drop for each longer wire run by using progressively larger diameter wire based on calculations.

 

[DIYrich]

Should all the inverters use 16 foot long AC output cables or is it OK for one to have 3 foot AC output cables, the next to have 5 foot cables, the next 8 foot.... etc until the final one has 16 foot long cables?

Haven't read about a need for "equal length" for AC.

If unequal lengths are used, will the house draw more power from the 3 foot inverter than from the 16 foot one? Or, is the EG4 inverter firmware able to mitigate the unbalanced lengths and ensure even draw to all paralleled inverters?

If the inverters are in parallel, then the Master will decide how much each inverter contributes. For example, the inverters with PV that are supplying power will be maxed out before inverters that would draw power from the battery.

If the inverters are not in parallel, then off-grid may be a problem.

 

[wpns]

My primary 18Kpv inverter usually contributes a little less than the secondary, and it has 5-foot shorter 1AWG wires. During the day they can vary a bit more (thanks, DIYrich!) but it’s never significant.

 

[mossymeadow]

Great to know the inverter firmware will make those calls - both in theory and in practice. I was hoping that would be the case! Thank you all