In terms of overcurrent/shortcircuit protection, are the conductors feeding off a panelboard's feed-thru lugs considered to be tap conductors and subject to Article 240.21? In particular, I have a 30hp 3ph, 208v, elevator application where I would like to utilize 240.21(F) and use the feed-thru lugs of a 400A main panel to feed the elevator controller breaker. Any and all guidance will be appreciated.
In this case, the tap conductors off the 400A feed thru lugs will terminate in a 225A breaker that will feed the elevator controller. The tap conductors are 2/0 awg thwn, which is more than 1/3 the ampacity of the panel board and main breaker(400A) feeding the panelboard. There is also less than 25 feet in length between the origin of the tap and the elevator breaker. I'm giving you more info to pull some more teaching out of you.
Re: Feed thru lugs on Panelboards#49844 03/18/0511:26 AM03/18/0511:26 AM
Greg, thanks for bantering back and forth with me. In this case, this 400A panel is also serving a number of small loads. The 30HP elevator controller is of a soft start type, but this manufacturer would not recommend a size breaker to feed the unit. I sized the the breaker based on 430.52(C)(1)excpt.(1). I was trying to avoid buying a panel that would handle a 200 or 225A OCPD feeder/branch device(puts you into a higher end panel) since I had to shunt trip anyway. This elevator moves people primarily.
Re: Feed thru lugs on Panelboards#49846 03/18/0511:51 AM03/18/0511:51 AM