Backup Generator Sizing EG4 6000XP (Parallel)

[JBoffgrid2022]

Hello!
Looking for some advice on generator sizing for (2) EG4 6000XP's in parallel. I have a Kohler 12kW off grid generator already at my off grid and would hate to have to sell that and install a larger generator. The total size of the two inverters would be 12kW however the manual that came with the inverter only gives instructions for one inverter. It mentions two things: 1 getting a generator that is 150% larger than the inverter (this would equate to a 18kW generator for both inverters). 2 keeping the generator connected to all inverters in parallel. Any advice would be appreciated! Thank you.

 

[BentleyJ]

It really is a matter of understanding your electrical needs and sizing the generator to satisfy the pass-thru amperage of any loads PLUS have some left over to charge batteries without pushing the generator to 100% of its rated capacity for long periods of time.

For example, say we don't want to run the generator over 8kW continuously and wish to limit any surges to 10kW for 10min or less. Will this fit within your power consumption parameters and still allow for battery charging if needed?

 

[JBoffgrid2022]

I think I get what you're saying. You're saying the inverter would only need enough power from the generator based on the load it's providing the house? If that were the case, we would need at any given moment roughly 8kW.

 

[Zapper77]

I think I get what you're saying. You're saying the inverter would only need enough power from the generator based on the load it's providing the house? If that were the case, we would need at any given moment roughly 8kW.

Did you figure this out?

 

[JBoffgrid2022]

Hello Zapper,
Thanks for checking back in. I ended up deciding to only put into service one 6k inverter. I ran into bigger issues with my system that forced me to only install one inverter at this time. Namely, I didn't have enough room on my roof for 32 450 watt panels which was what I was told to have to support two 6k inverters. It ended up being a good thing though because my 12k generator will tie in perfectly now because it is the right size for a 6k inverter

 

[AZ Solar Junkie]

Hello Zapper,
Thanks for checking back in. I ended up deciding to only put into service one 6k inverter. I ran into bigger issues with my system that forced me to only install one inverter at this time. Namely, I didn't have enough room on my roof for 32 450 watt panels which was what I was told to have to support two 6k inverters. It ended up being a good thing though because my 12k generator will tie in perfectly now because it is the right size for a 6k inverter

There's no MINIMUM amount of solar input for the 6000XP's. It's all a matter of your particular situation - how big your loads are, etc. During normal operation you just want enough solar power to both power your loads and get your batteries charged up...

 

[Madcodger]

It seems like EG4 is recommending a MUCH bigger generator for the 6000XP than is really necessary for most people. A person might need two of these inverters for occasional loads (let's run the dryer while we use the induction cooktop) but if you do some planning, just don't use heavy load appliances while you're running the generator to recharge batteries. Assuming they aren't maxing out their XP's most of the time, I can't see any reason most people need to buy an 18KW generator for a 12KW inverter system. Do your laundry on sunny days, and plan ahead to cook that Thanksgiving meal. Seems like cover their rear advice that would cause people to buy a much larger generator, with much higher fuel consumption, than is really needed if a person has common sense and does a little planning.

 

[Zapper77]

Edit - Generator size shouldn't be an issue after the next update.

3rd Edit. 180C0D firmware released and supports Generator Boost. I'll throw together a quick video.

 

[Onehand]

It seems like EG4 is recommending a MUCH bigger generator for the 6000XP than is really necessary for most people. A person might need two of these inverters for occasional loads (let's run the dryer while we use the induction cooktop) but if you do some planning, just don't use heavy load appliances while you're running the generator to recharge batteries. Assuming they aren't maxing out their XP's most of the time, I can't see any reason most people need to buy an 18KW generator for a 12KW inverter system. Do your laundry on sunny days, and plan ahead to cook that Thanksgiving meal. Seems like cover their rear advice that would cause people to buy a much larger generator, with much higher fuel consumption, than is really needed if a person has common sense and does a little planning.

This, I have had a hard time of letting go of. So it isn't THD and burning stuff up, why do I need a 18-24kw gen for running a light and a tv at the same time or charging batteries at 25 amps or even the max allowable the gen will provide and the XP will tolerate?

I believe my little 12kw gen will do just fine with 2 XP's, assuming I dont overload the gen or ask too much of the XP.

 

[AZ Solar Junkie]

This, I have had a hard time of letting go of. So it isn't THD and burning stuff up, why do I need a 18-24kw gen for running a light and a tv at the same time or charging batteries at 25 amps or even the max allowable the gen will provide and the XP will tolerate?

I believe my little 12kw gen will do just fine with 2 XP's, assuming I dont overload the gen or ask too much of the XP.

True if your loads are low enough

 

[Onehand]

Edit - Generator size shouldn't be an issue after the next update.

3rd Edit. 180C0D firmware released and supports Generator Boost. I'll throw together a quick video.

Zapper, where did that pic from EG4 go detailing the new updates? Would like to have that for my file.

 

[Zapper77]

Zapper, where did that pic from EG4 go detailing the new updates? Would like t have that for my file.

 

[Onehand]

View attachment 193894

Thank You Sir!