Service overcurrent protection

[hhsting]

I have 200A fused service disconnect fused at 200A. The incoming service conductors are 2/0 awg copper which is good for 175A. Demand load is 171 A.

Should not the fused in the main service disconnect be 175A and not 200A Or 2/0 awg change from 2/0 awg to 3/0 awg copper?


Sent from my iPhone using Tapatalk

 

[augie47]

Unless it's residential and meets 310.15(B)(7) or possibly Art 430 Part II

 

[roger]

Who owns the service conductors you are talking about? Are they POCO property?

 

[hhsting]

Who owns the service conductors you are talking about? Are they POCO property?

From the meter to fused disconnect customer owns them.

 

[hhsting]

Unless it's residential and meets 310.15(B)(7) or possibly Art 430 Part II

Thats right it was residential but now they are turning commercial. No longer residential. Restaurant

 

[don_resqcapt19]

Add a second service disconnect and the installation would be compliant with the 2/0.

 

[hhsting]

Which code section actually requires to change 2/0awg to 3/0 awg or 200A fuse to 175A fuse for commercial?

 

[infinity]

Which code section actually requires to change 2/0awg to 3/0 awg or 200A fuse to 175A fuse for commercial?

For a dwelling service you can apply the 83% rule to the conductors so 200*83%=166 amps minimum conductor size. #2/0@175 amps is code compliant. Once you go to a commercial service the 83% rule cannot be applied so the 200 amp OCPD would require a 200 amp conductor.

 

[don_resqcapt19]

Which code section actually requires to change 2/0awg to 3/0 awg or 200A fuse to 175A fuse for commercial?

230.90(A).