Define "Feed-Thru Lugs."

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charlie b

charlie b

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A co-worker and I have a difference of opinion on the meaning of this term. I would like to ask the members of this Forum whether you think the phrase ?feed-thru lugs? has more than one meaning.

Consider the following two configurations. In both cases, a Main Service Panel provides power to Panel #1, and power goes from Panel #1 to Panel #2. In both cases, Panel #1 has a Main Breaker, but there is no breaker from Panel #1 to Panel #2.
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  • <font size="2" face="Verdana, Helvetica, sans-serif">Case 1: The feeder from the Main to Panel #1 lands on one set of lugs (upstream of Panel #1?s Main Breaker). The feeder to Panel #2 is connected to a second set of lugs (also upstream of Panel #1?s Main Breaker), such that opening the Main Breaker on Panel #1 will not cause Panel #2 to lose power.</font>
<font size="2" face="Verdana, Helvetica, sans-serif"></font>
  • <font size="2" face="Verdana, Helvetica, sans-serif">Case 1: The feeder from the Main to Panel #1 lands on the only set of incoming lugs (upstream of Panel #1?s Main Breaker). The feeder to Panel #2 is connected to a second set of lugs at the bottom of the panel (downstream of Panel #1?s Main Breaker), such that opening the Main Breaker on Panel #1 does cause Panel #2 to lose power.</font>
<font size="2" face="Verdana, Helvetica, sans-serif">Questions:

1. Are both of these configurations real?

2. If so, can they both be described by the phrase ?feed-thru lugs??

3. Should the first case properly be called ?double-lugs,? and the second ?feed-thru lugs??

4. Should the first case properly be called ?feed-thru lugs,? with the second having some other name?
 
Re: Define "Feed-Thru Lugs."

It sounds to me like the first case would be a double lug feeder tap subject to the tap rules and the second case would be a feed through protected by main in panel 1
 
Re: Define "Feed-Thru Lugs."

Charlie
Is this a trick question?
1- Yes this a real life configuration
2- Both are not the same
3- This is what I would think of should I hear someone talking about ?double-lugs? or ?feed-thru? note I removed the word lugs
4- Whether proper or not I suppose that the ?double lug? could be referred to as a ?feed through lug? as it would have a line and a load connected to it. Like wise I suppose that the panel could be called a ?feed through panel? (this is what I call this type of panel instead of ?feed through lug?)
Be sure to post your opinion on this matter.
 
Re: Define "Feed-Thru Lugs."

I have been known to ask the occasional trick question, but this was not intended to be one of those. My opinion was that the phrase ?double lug? was unambiguous, but that the phrase ?feed-thru lugs? could have been used, at least conversationally, for both cases. I was curious as to whether there were a ?correct, technical use of the phrase. I particularly like canman?s way of distinguishing the two.

Many thanks for the responses.

By the way, my co-worker?s view was the same as yours.
 
Re: Define "Feed-Thru Lugs."

Charlie,I did a search on feed through lugs and came upon several load center and generator sites that showed lugs in both of the situations that you described and in both cases they called them feed through lugs.
 
Re: Define "Feed-Thru Lugs."

charlie b - Both situations are realistic, but electrically totally different.
Case 1 being known as sub feed lugs & Case 2 known as through feed lugs.

It is not correct to call them both "feed through lugs".

[ January 08, 2005, 07:31 PM: Message edited by: kiloamp7 ]
 
Re: Define "Feed-Thru Lugs."

The following is from Square D OD&E Construction Segment Training, digest 8, pages 25 through 28:

Sub Feed LUgs:
1. Used on Main Lug Panels Only
2. Daisy Chains two or more adjacent, typically, together
3. Adds additional box height in most cases

Feed-thru lugs:
1. Always mounted opposite of the main
2. Used on main lug or main breaker panels
3. Adds additional box height in all cases

Sub Feed circuit breakers:
1. Always mounted opposite of the main
2. Used on main lug or main breaker panels
3. Adds additional box height in all cases
 
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