LATTC Student
Member
- Location
- SoCal
- Occupation
- Student
Just deployed a small Enphase 1.5KW system on top of my shed at home in SoCal as Phase I of a larger deployment ~6KW.
FWIW: Currently using (5) IQ7+ (1.21 Max A/ea) and (5) 355W JA Solar panels. I have the Enphase Combiner Box 3.
Main panel is GE 100A/125A (breaker/Bus rating) and shed subpanel is the same rating (GE Gold Load Center 100A/125A). I have the main lug of the Combiner box connected to a 50A breaker in the bottom left slot in the subpanel (a throw switch shutoff box in between the two boxes). The subpanel main lug is fed from the Main Panel at my primary dwelling. The breaker, feeding the sub, at the main panel is also a 50A breaker (making it a 50A subpanel I guess). This breaker is almost right next to the main 100A service disconnect breaker - near the top of L2.
So I have two questions. If I understand the basic calc of the 120% - since my main and sub are 100/125, then i should be able to have a 50A "inverter" breaker at the sub (125*1.2-100=50A). Is it still required that I keep that 50A breaker at the bottom of the subpanel? Additionally, I am guessing that I would need to move my 50A breaker at the main panel to the bottom most right slot, correct?
I figure I have actual max current rating right now (@125%) from PV of ~7.5A ((5*1.21)*125%). Eventually that will quadruple to ~30A max (with a little room ~20A for growth). I saw a post elsewhere that the PV inverter breaker sizing had to be under the service breaker rating plus the 125% PV max A. So that would mean 107.5A (100A+7.5A) is under the 150A (125A*1.2) rating? I could scale to ~33 panels theoretically (100+(33*1.21)*125%) Seems like two different rules (120%/125%). Not sure which applies
To summarize the two main questions:
1) Do I need to move that main breaker (50A feeding sub) to the bottom most slot on the right bottom of main?
2) Is it ok to use a 50A PV "inverter" breaker in the sub if the main AND sub are both 100A/125A service/bus rated?
Note: I have the Sense consumption CT's in my main panel and at my sub. The (total) main peak KWh never goes over 5.5KWh (~45A) even with HVAC, etc. . .. The Sub never peaks over 1KW (7.7A) though that load is continuous.
FWIW: Currently using (5) IQ7+ (1.21 Max A/ea) and (5) 355W JA Solar panels. I have the Enphase Combiner Box 3.
Main panel is GE 100A/125A (breaker/Bus rating) and shed subpanel is the same rating (GE Gold Load Center 100A/125A). I have the main lug of the Combiner box connected to a 50A breaker in the bottom left slot in the subpanel (a throw switch shutoff box in between the two boxes). The subpanel main lug is fed from the Main Panel at my primary dwelling. The breaker, feeding the sub, at the main panel is also a 50A breaker (making it a 50A subpanel I guess). This breaker is almost right next to the main 100A service disconnect breaker - near the top of L2.
So I have two questions. If I understand the basic calc of the 120% - since my main and sub are 100/125, then i should be able to have a 50A "inverter" breaker at the sub (125*1.2-100=50A). Is it still required that I keep that 50A breaker at the bottom of the subpanel? Additionally, I am guessing that I would need to move my 50A breaker at the main panel to the bottom most right slot, correct?
I figure I have actual max current rating right now (@125%) from PV of ~7.5A ((5*1.21)*125%). Eventually that will quadruple to ~30A max (with a little room ~20A for growth). I saw a post elsewhere that the PV inverter breaker sizing had to be under the service breaker rating plus the 125% PV max A. So that would mean 107.5A (100A+7.5A) is under the 150A (125A*1.2) rating? I could scale to ~33 panels theoretically (100+(33*1.21)*125%) Seems like two different rules (120%/125%). Not sure which applies
To summarize the two main questions:
1) Do I need to move that main breaker (50A feeding sub) to the bottom most slot on the right bottom of main?
2) Is it ok to use a 50A PV "inverter" breaker in the sub if the main AND sub are both 100A/125A service/bus rated?
Note: I have the Sense consumption CT's in my main panel and at my sub. The (total) main peak KWh never goes over 5.5KWh (~45A) even with HVAC, etc. . .. The Sub never peaks over 1KW (7.7A) though that load is continuous.
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