ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
Pool - Daisy chained GFCI
by gfretwell. 05/18/19 01:30 PM
Chinese wire symbols?
by nmateik. 05/18/19 12:13 AM
110.26 working clearances
by HotLine1. 05/14/19 02:08 PM
Parallel SER Cables
by George Little. 05/03/19 05:42 PM
Norwegian power?
by dsk. 05/03/19 04:30 AM
New in the Gallery:
What is this for?
Plug terminals
Who's Online Now
0 registered members (), 7 guests, and 11 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Switching the neutral #211003
09/01/13 02:22 AM
09/01/13 02:22 AM
S
Stu T  Offline OP
Member
Joined: Mar 2001
Posts: 27
Stamford, CT
Can a standard 3 pole disconnect switch be used to switch 2 phase conductors and 1 neutral. My concern is the lack of accurate synchronization of the blades making to their respective contacts. If the neutral blade makes last it could cause over-voltage in the phase to neutral loads. Seems like the neutral blade would have to make 1st and break last. What about a 3 pole molded case circuit breaker ?
What do you think?
Thanks in advance.

Last edited by Stu T; 09/01/13 02:24 AM.
Work Gear for Electricians and the Trades
Re: Switching the neutral [Re: Stu T] #211004
09/01/13 02:29 AM
09/01/13 02:29 AM
G
gfretwell  Offline

Member
Joined: Jul 2004
Posts: 9,359
Estero,Fl,usa
It is "legal" but certainly a design issue, for exactly the reason you brought up. Whether a millisecond or so of unbalanced load would hurt anything is really a question of what the load is.
It is also a situation where you fail very "hard" if the neutral fails to make totally.
I would avoid it if at all possible.


Greg Fretwell

Featured:

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

 

Member Spotlight
Scott35
Scott35
Anaheim, CA. USA
Posts: 2,720
Joined: October 2000
Show All Member Profiles 
Top Posters(30 Days)
Popular Topics(Views)
255,001 Are you busy
191,137 Re: Forum
180,884 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.020s Queries: 15 (0.003s) Memory: 0.9431 MB (Peak: 1.0625 MB) Zlib enabled. Server Time: 2019-05-19 07:15:38 UTC