comm. service conductors

[haleyjo1]

In the area i am working everyone uses 2/0 copper for 200 amp services i think this is incorrect but cant seem to prove it .I know it is fine in a house but these are coommercial properties.

 

[goindowner]

Table 310.15 B 6 is only for single phase dwellings services. Table 310.16 appears to the table that should be used.

 

[barbeer]

Your assumptions are more than likely correct, 310.16 does not rate 2/0 CU for 200 amps in the 75 degree column which is mostly used today. However, if the connected load does not exceed the rating of the conductor it could be installed with the next higher breaker size. 240.4

 

[don_resqcapt19]

barbeer,

However, if the connected load does not exceed the rating of the conductor it could be installed with the next higher breaker size. 240.4

No, that is not possible in this case. The rating of 2/0 in the 75?C column is 175 amps and that is a standard OCPD size so there is no next larger standard size. 240.6
Don

 

[dana1028]

Your assumptions are more than likely correct, 310.16 does not rate 2/0 CU for 200 amps in the 75 degree column which is mostly used today. However, if the connected load does not exceed the rating of the conductor it could be installed with the next higher breaker size. 240.4

You can only use the 'next higher breaker' rule when your conductors do not correspond with a standard rating of a fuse/breaker. 2/0 at 75 degrees is good for 175A, and that is a standard size [240.6]

[Don is supposed to be at work and not sitting here reading and responding to forum discussions at this time of day].

 

[don_resqcapt19]

Don is supposed to be at work and not sitting here reading and responding to forum discussions at this time of day

It is break time here:smile:

 

[cpal]

does this service have a 200A main??

Or some combination of ocpd that sum to 200A???

230.90(A) exc#3

 

[barbeer]

barbeer,

No, that is not possible in this case. The rating of 2/0 in the 75?C column is 175 amps and that is a standard OCPD size so there is no next larger standard size. 240.6
Don

You are correct sir! Even inspectors slip up sometime.

 

[augie47]

break

break

It is break time here:smile:

Gentlemen: I believe we have an example of the highest form of dedication to Mike's forum. H0Hos and soft drinks be damned, its breaktime and I;m going to my laptop!