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#166548 07/23/07 04:04 PM
Joined: Jan 2005
Posts: 5,349
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Cat Servant
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Picture submitted by Waymag. He'll fill in the details:

[Linked Image]

Last edited by renosteinke; 07/24/07 07:28 PM.
Joined: Jun 2005
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Lightning?

ShockMe77 #166570 07/23/07 08:26 PM
Joined: Jan 2002
Posts: 70
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We still do not know what made this switch have a melt down. It was on a 277volt circuit and the breaker never tripped. The breaker was a Cutler Hammer Power Line c style breaker. This is also a code violation type deal because 120 and 277 were in the same box. I know the contacts inside the switch had welded together.

waymag #166573 07/23/07 08:40 PM
Joined: Dec 2000
Posts: 4,289
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The 120V switch and 277V switch can be in the same box IF the voltage between 2 adjacent switches doesn't exceed 300V.

It's in 404.8(B) smile

(I wonder what the voltage between the 2 systems is?)


electure #166579 07/23/07 09:21 PM
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Perhaps the switch was not rated for 277?

electure #166601 07/24/07 10:45 AM
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Originally Posted by electure
(I wonder what the voltage between the 2 systems is?)


Best case = 157V, worst case = 397V, depending upon phasing.

pauluk #166626 07/24/07 08:55 PM
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My, how simple! laugh

electure #166627 07/24/07 09:12 PM
Joined: Jan 2002
Posts: 70
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Well it had 120v and basically 480v too because the other 2 switches were 277 on a phase and 277 on b phase... 1-120v switch and 2-277 volt switches...after repullint wire back up to j box I did an amp reading and got 4 amps on the 120v switch 3.5 on one of the 277 volt switches and 1.5 on the other 277 volt switch.


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