Repost of unanswered question

[hornetd]

I hope it is OK to repost this to the new forum. I want to make sure that the anser I provide is pear reveiwed.

Name: Edward Chalke
Email: greenejeep@msn.com
Location: Florida
Title: Maintenance
In Trade Since: 1976
Registered: Oct 2001
Total Posts: 23
posted February 25, 2003 at 08:48 AM

This is the actual question in clear explanation. except, this is not my job, it is a question of a job done by a homeowner who is refering to me for an answer. thanks for all of you and your help on this:

quote
elect7tcode@aol.com Ed Chalke: ''If I understand your installation correctly, U have a 200 amp panelboard that has 200 amp main bus with lugs on it. The bus is a feeder on the load side of a 200 amp breaker. You have tapped off of the bus with 200 ampere wire, so it is not a TAP! It is a 200 ampere feeder supplying 100 ampere panelboard. The panelboard being supplied must have overcurrent protection not greater than the rating of the panelboard, 100 amps.'' end quote


the home panel does have a 100 amp main.

o.k. now the question is : does this feeder require 100 amp fusing at both ends?

I believe that the installation you describe is code compliant. The conductors that run from the feed through lugs are feeder conductors. They are protecte at their ampacity. They supply a panelboard that is protected it's ampacity.

I am curious as to why a two hundred ampere feeder was installed to supply a one hundred ampere load. I am also presuming that the two hundred ampere pole mounted service equipment is within the requisite thirty feet of the manufactured home.
--
Tom Horne

 

[rb]

Re: Repost of unanswered question

Ed,

If the 200 amp conductors are protected at their rated ampacity they are not tap conductors. The conductors are adequately protected, no problem. The panelboard is protected by the 100 amp circuit breaker, no problem there either.

You are permitted to make a tap of a feeder in accordance with 240.21(B). If the conductors feeding the 100 amp panel are 25 ft or less, and have an ampacity of at least 100 amps (the minimum necessary to terminate into a 100 amp overcurrent device), overcurrent protection is not required where these conductors are tapped to the 200 amp bus.

 

[tom baker]

Re: Repost of unanswered question

A 200 amp pole mounted service may of been installed as it was on sale or closeout. Often 200 amp panels are cheaper than 100 Amp due to volume. Or someone purchased it not really knowing.