National electrical Code Tap rule
National electrical Code Tap rule
(OP)
I am interested in obtaining input to whether a tap of a bus in a switchboard, panelboard is permitted by the NEC. In looking through the code recently I could not find this although I have seen it done on numerous occasions.





RE: National electrical Code Tap rule
Short answer: Yes, taps are allowed under certain conditions. There are different rules depending on length of tap.
RE: National electrical Code Tap rule
The problem is UL, not NEC. Drilling holes in your bus will irreversibly violate the UL listing.
RE: National electrical Code Tap rule
RE: National electrical Code Tap rule
Just curious, whose board was it? I was recently asked to explore recertification of two boards that had been similarly raped by a contractor, and both manufacturers (GE and Cutler-Hammer) declined to repair or recertify.
RE: National electrical Code Tap rule
Most panelboard suppliers can provide "sub-feed" and "through-feed" lug kits that will accomplish the same thing and allow you to keep your rating. The sub-feed kits are available only for main lugs only panels.
Another option is to use "gutter taps". You can use split-bolt or other types of connectors to tap the incoming **cable** not the bus. This is allowed by NEC and UL, provided you have enough room in the gutter or wireway.
Of course, the local inspector gets the last word...
RE: National electrical Code Tap rule
RE: National electrical Code Tap rule
Look at it from GE's perspective - what is in it for them, besides increased liability should this panel cause someone an injury, for any reason, in the next 40 years?
Good luck, and consider bringing in some doughnuts for your local inspector.