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line side of disconnect #72964 12/12/06 11:54 PM
Joined: Apr 2002
Posts: 32
S
sudsy4 Offline OP
Member
Is there a requirement for line side conductors to be terminated on the top of a disconnect, or was that just a known way to do it. Been seeing alot of factory wired equipment pre-wired with the line conductors expected to terminate at the bottom of the disconnect device (breaker).
For 35 years, this was always unexceptable to me...line top, load bottom.


Bill
Work Gear for Electricians and the Trades
Re: line side of disconnect #72965 12/13/06 01:01 AM
Joined: Mar 2005
Posts: 48
R
Rich Thomas Offline
Member
That's a good question.

I also thought line was on top. I thought line had to be on top so the arc squelch mechanism operated correctly when the breaker opens.

Re: line side of disconnect #72966 12/13/06 03:22 AM
Joined: May 2003
Posts: 2,876
E
e57 Offline
Member
In the trade for about 1/2 of that 35, and I too remember it the same way, but have noticed that it is no longer the case. I'm sure it was a requirement at some point, but can't tell you when it was removed - But I think "Line" was stamped at the top for everything for quite some time after that. "line on top" - is something that I was always told....

Or, maybe the last vestages of any wording that may have implied it are in 404.6(A-C)

"Single-throw knife switches shall be placed so that gravity will not tend to close them." And, by design... it ended up that way - 'Line on top'.


Mark Heller
"Well - I oughta....." -Jackie Gleason
Re: line side of disconnect #72967 12/13/06 05:42 AM
Joined: Jul 2004
Posts: 101
J
jraef Offline
Member
I'm not 100% sure, but I believe the issue is, you are required to connect in the manner proscribed by the device manufacturer, and they almost all say Line on top, Load on bottom. If you have to do it differently for some reason, you have to get special labels indicating the change so that some future electrician would not make a careless mistake by assuming the convention. I got that info from an inspector on a job where I had to back-feed a main circuit breaker.


JRaef
Re: line side of disconnect #72968 12/13/06 05:56 AM
Joined: Jan 2003
Posts: 4,391
I
iwire Offline
Moderator
Not many single throw switching devices are marked line and load anymore.

Fused disconnects have to de-energize the fuses, that eliminates any options with those.

Most breakers can be used any direction,

Quote
I got that info from an inspector on a job where I had to back-feed a main circuit breaker.


I agree it is a good idea bit the inspector was asking for something that is not required by the NEC

Quote
Or, maybe the last vestages of any wording that may have implied it are in 404.6(A-C)

"Single-throw knife switches shall be placed so that gravity will not tend to close them." And, by design... it ended up that way - 'Line on top'.


Once you get to double throw (a manual ATS for example) that goes out the window.


Bob Badger
Construction & Maintenance Electrician
Massachusetts
Re: line side of disconnect #72969 12/13/06 01:19 PM
Joined: Jul 2004
Posts: 9,394
G
gfretwell Offline
Member
The only limiting rule is the way the handle operates.


Greg Fretwell
Re: line side of disconnect #72970 12/13/06 01:23 PM
Joined: Jan 2005
Posts: 91
H
Helectric Offline
Member
I think that 404.6 is about it for code regarding this.

Re: line side of disconnect #72971 12/13/06 11:22 PM
Joined: Apr 2002
Posts: 32
S
sudsy4 Offline OP
Member
Thanks for the replies


Bill

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