I know this might seem basic. I do need some clarification I would also like if at all possible to keep this simple.
Assume no Derates here, As an example PV source circuit 6.46 ISC x 22 strings in parallel 142.12 ISC x 125% = 177.65 (690.8 A1) conductors must be able to carry this current. So this would imply 3/0 Cu at 75d for 200 amps.
Next OCPD 690-8b1 require OCPD to be 125% of of the above 177.65 so 177.65 x125%= 222.0 OCPD must be rated to carry this number ...therefore a 225 amp breaker or fuse.
So do I now increase the size of the 3/0 conductor to 4/0 copper to protect the conductor from the possibility of current flow exceeding the value of the OCPD
Or do I simply have wire sized at 125% of ISC and A breaker sized 125% of of this calculated value?
Thank you
Assume no Derates here, As an example PV source circuit 6.46 ISC x 22 strings in parallel 142.12 ISC x 125% = 177.65 (690.8 A1) conductors must be able to carry this current. So this would imply 3/0 Cu at 75d for 200 amps.
Next OCPD 690-8b1 require OCPD to be 125% of of the above 177.65 so 177.65 x125%= 222.0 OCPD must be rated to carry this number ...therefore a 225 amp breaker or fuse.
So do I now increase the size of the 3/0 conductor to 4/0 copper to protect the conductor from the possibility of current flow exceeding the value of the OCPD
Or do I simply have wire sized at 125% of ISC and A breaker sized 125% of of this calculated value?
Thank you