Tapping Primary

[Pierre C Belarge]

Has anyone ever tapped primary conductors?
I was asked this question tonight, and I did not know if it has ever been performed, or if it is not permitted to be so.

 

[quogueelectric]

Has anyone ever tapped primary conductors?
I was asked this question tonight, and I did not know if it has ever been performed, or if it is not permitted to be so.

Yes on mv switchgear at the service to huntington quad for service to new building chiller.

 

[dcspector]

Yes on mv switchgear at the service to huntington quad for service to new building chiller.

I am confused are you refering to the tap section in the gear? That would be secondary from poco. I may have misunderstood you.

 

[drbond24]

I did a design once that triple-tapped the primary side of a transformer...don't know that it was permitted though.

There wasn't another transformer for hundreds of yards and the lead time on a new one was too long. The building had to come up RIGHT NOW, so I said the only way to get power RIGHT NOW is to make another tap on that transformer that is already double tapped. The maintenance guys threw a fit, but it went in and it is probably still there too.

 

[Pierre C Belarge]

Yes on mv switchgear at the service to huntington quad for service to new building chiller.

This is the purpose of the tapping.

By primary, I do not mean the primary of a transformer, I mean 13800V primary.

 

[quogueelectric]

This is the purpose of the tapping.

By primary, I do not mean the primary of a transformer, I mean 13800V primary.

Yes understood . The building has a primary(medium voltage )4160 I BELIEVE Interior distribution system Very uncommon by me Now we are talking concentric neutrals, semiconductor wrapped Crossed link propylene cables, loadbreak elbows, Stress cones . I believe one of the contractors was angry with me because I refused to do the grounding inside the gear when the gear was live. I said if you are that sure it is not dangerous why dont you come over and do it. I always liked fireworks displays. Wanted to give me a helper so I could kill him too.

 

[charlie]

Has anyone ever tapped primary conductors? . . . or if it is not permitted to be so.

Yes, we do it all the time. :smile:

Read 240.100(A) 'when designed under engineering supervision' and 240.101(B) for doing it under the NEC instead of the NESC.