ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
Danish type K Sockets
by winston_1 - 10/25/21 07:30 PM
Flexible Conduit?
by gfretwell - 10/24/21 01:59 AM
May I backfeed 3 phase transformer?
by dsk - 10/22/21 04:37 AM
Wire sizing
by gfretwell - 10/21/21 10:12 PM
GFCI's pops in large numbers
by dsk - 10/21/21 02:03 AM
New in the Gallery:
240/208 to a house
240/208 to a house
by wa2ise, October 9
Now you know.
Now you know.
by Tom_Horne, September 7
Who's Online Now
0 members (), 36 guests, and 16 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
#166548 07/23/07 04:04 PM
Joined: Jan 2005
Posts: 5,316
Cat Servant
Member
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
Posts: 821
S
Member
Lightning?

ShockMe77 #166570 07/23/07 08:26 PM
Joined: Jan 2002
Posts: 70
Member
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: 4,288
Member
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
Joined: Jan 2005
Posts: 5,316
Cat Servant
Member
Perhaps the switch was not rated for 277?

electure #166601 07/24/07 10:45 AM
Joined: Aug 2001
Posts: 7,520
P
Member
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
Joined: Dec 2000
Posts: 4,288
Member
My, how simple! laugh

electure #166627 07/24/07 09:12 PM
Joined: Jan 2002
Posts: 70
Member
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.


Link Copied to Clipboard
Featured:

Tools for Electricians
Tools for Electricians
 

* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
pcsailor
pcsailor
Minneapolis, MN, USA
Posts: 21
Joined: September 2019
Top Posters(30 Days)
dsk 7
wa2ise 1
Popular Topics(Views)
284,930 Are you busy
217,466 Re: Forum
203,765 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.5