MLO Sub-panel with inverter and loads wire sizing

Status
Not open for further replies.

ryangittens

Member
Location
usa
Hey Guys,

I have a situation and wondering if my thinking is correct and looking for the applicable codes.

I have a 60A subpanel which has a 20A breaker for an inverter and a 20A breaker for a light.

This would be legal according to the sum rule in 705.12(d)(2)(3)(c). But how do we size the wires coming out of the subpanel? Because the currents are going in opposite directions the max current on that wire be 20A and should be sized for that shouldn't it?


Thanks
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
Hey Guys,

I have a situation and wondering if my thinking is correct and looking for the applicable codes.

I have a 60A subpanel which has a 20A breaker for an inverter and a 20A breaker for a light.

This would be legal according to the sum rule in 705.12(d)(2)(3)(c). But how do we size the wires coming out of the subpanel? Because the currents are going in opposite directions the max current on that wire be 20A and should be sized for that shouldn't it?


Thanks

Yes. The most current those conductors will carry is 20A.
 

ryangittens

Member
Location
usa
Hey Guys,

I have a situation and wondering if my thinking is correct and looking for the applicable codes.

I have a 60A subpanel which has a 20A breaker for an inverter and a 20A breaker for a light.

This would be legal according to the sum rule in 705.12(d)(2)(3)(c). But how do we size the wires coming out of the subpanel? Because the currents are going in opposite directions the max current on that wire be 20A and should be sized for that shouldn't it?


Thanks

Just realized that this is a stupid question. The conductors are sized based on and protected by the OCPD on the other end.
 
Status
Not open for further replies.
Top