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#112073 - 02/17/01 08:33 PM 3 Phase Panel fed from Single Phase Panel
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Loc: NY, USA
Submitted by Frank Cinker

Click Photo for a closer look


Three phase main lug only panelboard is fed from a single phase service

panelboard 30 ft. away. A 100 Amp. three pole breaker in the single
phase

panelboard is protecting feeder conductors and sub panel.
Frank Cinker

Pittsburgh, PA.

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#112074 - 02/18/01 04:00 AM Re: 3 Phase Panel fed from Single Phase Panel
sparky Offline
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Registered: 10/18/00
Posts: 5545
So..would this be the infamous "Delta Breaker" in 384-16-f ?

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#112075 - 02/18/01 05:58 AM Re: 3 Phase Panel fed from Single Phase Panel
cinkerf Offline
Member

Registered: 12/03/00
Posts: 81
Loc: Pittsburgh, Pennsysvania. ...
Sparky,

You are correct. I presented this code violation in a previous post. (Code Forum) I thought I would send a photo of the sub-panel. As you can see at a glance, it looks perfectly legal. (Without taking voltage readings) Once the Inspector had the service panelboard cover removed the code violation was quite obvious.

Frank (cinkerf)

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#112076 - 02/19/01 04:55 PM Re: 3 Phase Panel fed from Single Phase Panel
sparky Offline
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Registered: 10/18/00
Posts: 5545
Frank;
The Delta breaker deal has been, to my knowledge, a no-no for 2 or 3 decades.

There is confusion as to how the introdution of a third leg ( or in this case 2-A legs, 1-B leg ) was accomplished, simply because nobody is going to advertise this .

This makes it something of a curious oddity to newer trade members as I , who have really only been seriously involved at it since the mid-80's

Perhaps you could give us a little history thread on this sometime here?

PS- I wonder if that 2-pole GFI would work on A+A phase ??


[This message has been edited by sparky (edited 02-19-2001).]

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#112077 - 02/19/01 05:31 PM Re: 3 Phase Panel fed from Single Phase Panel
Bill Addiss Offline
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Registered: 10/07/00
Posts: 4196
Loc: NY, USA
Sparky,

Frank said that a 3pole 100a breaker was in the singlephase panel that fed this. That's where the 3 wires come from - ABA or BAB sequence I would assume.

Bill

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#112078 - 02/21/01 10:56 PM Re: 3 Phase Panel fed from Single Phase Panel
therain4 Offline
Member

Registered: 12/18/00
Posts: 37
Loc: Dunmore,Pa. U>S.A.
Sparky go to electricalzone.com click on
article search and type delta breaker.If I can think of any more references I will keep you posted.

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#112079 - 02/23/01 05:32 PM Re: 3 Phase Panel fed from Single Phase Panel
sparky Offline
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Registered: 10/18/00
Posts: 5545
http://www.electricalzone.com/archive/search_display.asp?ID=19970201ecm

Delta breaker article, worth reading, thanks Rain

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#112080 - 02/23/01 06:08 PM Re: 3 Phase Panel fed from Single Phase Panel
Bill Addiss Offline
Member

Registered: 10/07/00
Posts: 4196
Loc: NY, USA

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#112081 - 02/23/01 06:53 PM Re: 3 Phase Panel fed from Single Phase Panel
sparky Offline
Member

Registered: 10/18/00
Posts: 5545
Thanks Bill

This Delta deal is a well thought, but dangerous arangement

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