The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
230 or 345 kV transmission lines?
by Vlado
09/24/16 09:33 AM
breaker meltdown
by crselectric
09/24/16 12:42 AM
Electrical mast flashing product
by ThomasWinfrey
09/22/16 12:14 AM
What estimating software do you recommend?
by sparky
09/21/16 07:20 PM
"Dry Run" Inspection goes awry
by HotLine1
09/20/16 07:39 PM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
HotLine1 18
sparky 9
gfretwell 9
sparky66wv 8
Vlado 6
Who's Online
0 registered (), 253 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#211003 - 08/31/13 11:22 PM Switching the neutral
Stu T Offline
Member

Registered: 03/17/01
Posts: 28
Loc: 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.


Edited by Stu T (08/31/13 11:24 PM)

Top
Work Gear for Electricians and the Trades

Work Gear for Electricians and the Trades
Work Gear for Electricians and the Trades
Arc Flash Clothing, Gloves, KneePads, Tool Belts, Pouches, Tool Carriers, etc. etc....

#211004 - 08/31/13 11:29 PM Re: Switching the neutral [Re: Stu T]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9012
Loc: 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

Top



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals