Is this code compliant?

[euboss]

Recently I contracted to replace the copper conductors from the power companies transformer to the main distribution panel of an empty commercial building. The copper conductors were stolen in the middle of the night by thieves The service was a 3 phase 1200 amp 4 wire 120/208 volt system. When I looked at the job, the power company's pad-mount transformer had short pieces of 500 mcm that were cut off near the termination at the transformer. I intended to replace the feeders with (3) sets of (4) 500 mcm THHN copper conductors to the 1200 amp breaker. If you go to 310-16, (3) sets of 500 MCM Copper THHN is only good for 380 amps per run for a total of 1140 amps. Am I allowed to go to the next common breaker size?

 

[LEO2854]

Recently I contracted to replace the copper conductors from the power companies transformer to the main distribution panel of an empty commercial building. The copper conductors were stolen in the middle of the night by thieves The service was a 3 phase 1200 amp 4 wire 120/208 volt system. When I looked at the job, the power company's pad-mount transformer had short pieces of 500 mcm that were cut off near the termination at the transformer. I intended to replace the feeders with (3) sets of (4) 500 mcm THHN copper conductors to the 1200 amp breaker. If you go to 310-16, (3) sets of 500 MCM Copper THHN is only good for 380 amps per run for a total of 1140 amps. Am I allowed to go to the next common breaker size?

250.4 (C) Overcurrent Devices Rated over 800 Amperes. Where the overcurrent device is rated over 800 amperes, the ampacity of the conductors it protects shall be equal to or greater than the rating of the overcurrent device defined in 240.6.

You can make the breaker smaller...:thumbsup:

 

[iwire]

The NEC may not even apply to those conductors.

They may be ahead of the service point.

But if it does you will need to run three sets of 600 copper to make it NEC compliant.

The section Leo posted does not apply above 800 amps.

 

[petersonra]

maybe he could set the Cb for 1140 amps.

 

[GoldDigger]

The section Leo posted does not apply above 800 amps.

It looks to me as if the quoted section only applies above 800A.


Tapatalk!

 

[iwire]

It looks to me as if the quoted section only applies above 800A.

Does it help the OP?

 

[GoldDigger]

No, but that does not mean that it does not apply. The poster of that section implied that it hurt the OP.

Tapatalk!

 

[iwire]

No, but that does not mean that it does not apply.

The world is a better place now that you have pointed out my error that does not change anything.

 

[GoldDigger]

I agree.:angel:

Tapatalk!