Buss Plug - Tap Rule

[DSpencerMEP]

If a buss plug is tapped off of a buss duct, do you have to use the tap rule in your calculation?

 

[petersonra]

If a buss plug is tapped off of a buss duct, do you have to use the tap rule in your calculation?

Only if it is a tap. if the conductors are protected at their ampacity it is not a tap.

 

[DSpencerMEP]

Reference

Reference

Do you know where I can find that referenced in the code book? My boss will ask me for that.

 

[petersonra]

by definition a tap conductor is a conductor that is not protected at its ampacity.

So if your buss plug has fuses in it that protect the downstream conductors at their ampacity, they are not tap conductors.

For instance: say you put 150A fuses in the buss plug (or the buss duct has 150A protection), then a 1/0 (or larger) conductor would not be a tap conductor.

If these conductors are not protected at their ampacity, they have to follow the tap rules.

240.2
Tap Conductors. As used in this article, a tap conductor is
defined as a conductor, other than a service conductor, that
has overcurrent protection ahead of its point of supply that
exceeds the value permitted for similar conductors that are
protected as described elsewhere in 240.4

 

[DSpencerMEP]

Thanks a million!

Thanks a million!

Thank you, and have a great day!