Bonding of feeder taps' enclosures

[darekelec]

Hello.
What are the rules for bonding enclosures when tapping from feeder? Should the bonding wire be sized according to feeder or tap conductors?
And what if I am using emt? Do I have to pull bonding conductor or does emt take care of that?
Thank you and have a great weekend.

 

[don_resqcapt19]

The EGC size is based on the supply side OCPD. EMT is suitable for use as the required EGC per the NEC, but many times the design documents call for an EGC of the wire type.

 

[kwired]

Hello.
What are the rules for bonding enclosures when tapping from feeder? Should the bonding wire be sized according to feeder or tap conductors?
And what if I am using emt? Do I have to pull bonding conductor or does emt take care of that?
Thank you and have a great weekend.

You do not bond to the neutral for one thing, a feeder is beyond the service equipment and everything beyond service is bonded to "equipment grounding conductor" and is based on the upstream overcurrent device - not the size of ungrounded conductors. However conductors that are increased in size because of voltage drop or other reasons must also have a similar increase in size of the equipment grounding conductor. One more thing that may come up is that the equipment grounding conductor never will be required to be larger than the associated ungrounded conductors. (tap a 100 amp feeder with a 20 amp conductor - the EGC associated with the tap will not need be larger than the 20 amp conductor)

 

[infinity]

Hello.
What are the rules for bonding enclosures when tapping from feeder? Should the bonding wire be sized according to feeder or tap conductors?
And what if I am using emt? Do I have to pull bonding conductor or does emt take care of that?
Thank you and have a great weekend.

The EMT would qualify as the EGC so a separate wire type EGC is not required. If one is used then it would be sized according to the OCPD ahead of the feeder and T250.122.