EG4 18k or Sol-Ark 15k: Whole House Mode on a 125Amp breaker

[jscmanson]

Hello to the community. I am looking to put in a solar panel and battery system for my 200A serviced 2000 sf SFD with a heat pump. The radiant heat is gone, and my total load calc is now around 120 amps. Rather than go through all the drama and expense of the expensive 200A disconnects, and I want to upgrade my main panel anyways, I'm thinking of doing the following setup:

1. Replace 200A main panel with a 175 Amp main panel (225 bus bar);
2. Put in a second 'sub' panel next to the main, put say 100 amps of load on the sub;
3. Feed the sol-ark from the main with a 125 amp breaker;
4. Set up the sol -ark to run as a 'whole home' setup, which gives 200A max feedthrough (but will never exceed 125 amps);
5. The output from the sol-ark would feed the sub panel (70a max when the grid is down, 125 max when it's not);
6. I'll put most of the breakers on the sub panel, my load testing shows that I should stay under 15kw with the heating loads and tesla all drawing power at same time.

So what I am doing is setting up the system in a 'partial home backup' configuration, but exceeding the 70 amp maximum breaker size that EG4's manual talks about in partial backup mode. EG4 says that 70 amps is the maximum load allowable in 'partial' backup mode, but can't I run the thing an 'whole house' mode but use a 125 amp feed instead of a 200a feed?

John

 

[timselectric]

No matter which one you choose. Both can pass through up to 200a (125a in your case) and provide up to 12kw continuously from the battery.

 

[DIYrich]

Just a guess: wouldn't a disconnect be cheaper than replacing a main panel? Put a sub panel on the smart load port, and move your non-critical circuits to that.

 

[Quattrohead]

Sounds like the perfect application for the the upcoming grid boss from EG4.
It has three input ports for inverters and 4 smart ports rated at 125 / 80 / 80 / 60 A that can be used as inputs or outputs and controlled based on various scenarios. It also has main breaker input and a bypass switch.

 

[Oldphile]

Hello to the community. I am looking to put in a solar panel and battery system for my 200A serviced 2000 sf SFD with a heat pump. The radiant heat is gone, and my total load calc is now around 120 amps. Rather than go through all the drama and expense of the expensive 200A disconnects, and I want to upgrade my main panel anyways, I'm thinking of doing the following setup:

1. Replace 200A main panel with a 175 Amp main panel (225 bus bar);
2. Put in a second 'sub' panel next to the main, put say 100 amps of load on the sub;
3. Feed the sol-ark from the main with a 125 amp breaker;
4. Set up the sol -ark to run as a 'whole home' setup, which gives 200A max feedthrough (but will never exceed 125 amps);
5. The output from the sol-ark would feed the sub panel (70a max when the grid is down, 125 max when it's not);
6. I'll put most of the breakers on the sub panel, my load testing shows that I should stay under 15kw with the heating loads and tesla all drawing power at same time.

So what I am doing is setting up the system in a 'partial home backup' configuration, but exceeding the 70 amp maximum breaker size that EG4's manual talks about in partial backup mode. EG4 says that 70 amps is the maximum load allowable in 'partial' backup mode, but can't I run the thing an 'whole house' mode but use a 125 amp feed instead of a 200a feed?

John

Someone correct me if I'm wrong, but the wouldn't the 120 rule limit the breaker feeding the Sol-Ark to 95A?
225x120% = 270-175 = 95A.