ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
Trumpy 5
Recent Posts
Another generator question
by gfretwell. 09/21/17 02:41 PM
What do you do?
by gfretwell. 09/21/17 02:33 PM
Supporting conduit bodies
by ghost307. 09/18/17 12:12 PM
Thermal Imaging Camera upgrade
by Potseal. 09/18/17 11:57 AM
Linear Power Supply Quits Under Load
by JoeTestingEngr. 09/15/17 11:37 PM
New in the Gallery:
Gallery Test
Popular Topics(Views)
240,854 Are you busy
176,605 Re: Forum
168,520 Need opinion
Who's Online Now
0 registered members (), 67 guests, and 7 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#166548 - 07/23/07 04:04 PM Burned Switch  
renosteinke  Offline
Cat Servant
Member
Joined: Jan 2005
Posts: 5,316
Blue Collar Country
Picture submitted by Waymag. He'll fill in the details:

[Linked Image]

Last edited by renosteinke; 07/24/07 07:28 PM.

Tools for Electricians:

#166568 - 07/23/07 07:53 PM Re: Burned Switch [Re: renosteinke]  
ShockMe77  Offline
Member
Joined: Jun 2005
Posts: 821
Rahway, New Jersey
Lightning?


#166570 - 07/23/07 08:26 PM Re: Burned Switch [Re: ShockMe77]  
waymag  Offline
Member
Joined: Jan 2002
Posts: 67
dallas, texas, USA
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.


#166573 - 07/23/07 08:40 PM Re: Burned Switch [Re: waymag]  
electure  Offline


Member
Joined: Dec 2000
Posts: 4,261
Fullerton, CA USA
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?)



#166579 - 07/23/07 09:21 PM Re: Burned Switch [Re: electure]  
renosteinke  Offline
Cat Servant
Member
Joined: Jan 2005
Posts: 5,316
Blue Collar Country
Perhaps the switch was not rated for 277?


#166601 - 07/24/07 10:45 AM Re: Burned Switch [Re: electure]  
pauluk  Offline
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Originally Posted by electure
(I wonder what the voltage between the 2 systems is?)


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


#166626 - 07/24/07 08:55 PM Re: Burned Switch [Re: pauluk]  
electure  Offline


Member
Joined: Dec 2000
Posts: 4,261
Fullerton, CA USA
My, how simple! laugh


#166627 - 07/24/07 09:12 PM Re: Burned Switch [Re: electure]  
waymag  Offline
Member
Joined: Jan 2002
Posts: 67
dallas, texas, USA
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.



Member Spotlight
Scott35
Scott35
Anaheim, CA. USA
Posts: 2,707
Joined: October 2000
Show All Member Profiles 
Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.017s Queries: 15 (0.003s) Memory: 0.7927 MB (Peak: 0.9581 MB) Zlib enabled. Server Time: 2017-09-21 19:37:18 UTC