ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
twh 10
Admin 4
Recent Posts
Any UL 508 experts out there?
by jraef. 05/23/17 07:31 PM
Dryer, Range grounding from "Main" panel
by sparkync. 05/23/17 03:32 PM
Heat pump conundrum
by sparkyinak. 05/21/17 08:49 PM
Interesting week
by HotLine1. 05/20/17 11:57 AM
Electrical Pricing Guide
by ElectricianBud. 05/18/17 12:17 PM
New in the Gallery:
SE cable question
Popular Topics(Views)
236,674 Are you busy
171,656 Re: Forum
164,631 Need opinion
Who's Online Now
0 registered members (), 58 guests, and 9 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#89574 - 10/09/04 06:13 AM Multiwire Branch Circuit with Unequal OCP  
iwire  Offline
Moderator
Joined: Jan 2003
Posts: 4,391
North Attleboro, MA USA
I am currently remodeling office space, I have an existing 8/3 AC cable that runs from a panel 125' to a kitchenette.

I plan to use this 8/3 AC as a multiwire branch circuit to feed a 120 volt 3000 watt water heater, the other side of this circuit will feed a 20 amp receptacle for a refrigerator.

This will mean I will have a single pole 35 and a single pole 20 feeding this multiwire branch circuit.

I see no problem with this, however my coworkers think I am nuts, and who would know that better then them. [Linked Image]

Am I missing something, is this a NEC violation?

Any responses are appreciated.

Thanks, Bob


Bob Badger
Construction & Maintenance Electrician
Massachusetts

2017 / 2014 NEC & Related Books and Study Guides

#89575 - 10/09/04 08:34 AM Re: Multiwire Branch Circuit with Unequal OCP  
George Little  Offline
Member
Joined: Jan 2004
Posts: 1,489
Michigan USA
Bob I think you comply with 210.4(C) and I assume that the common conductor of the circuit is insulated and that there is also an equipment grounding conductor. Where do I put the green sticker?


George Little

#89576 - 10/09/04 12:52 PM Re: Multiwire Branch Circuit with Unequal OCP  
electricman2  Offline
Member
Joined: Nov 2003
Posts: 269
Thomasville, NC USA
Go for it. Nothing says that the OCPD's have to be equal. [Linked Image]


John

#89577 - 10/09/04 11:15 PM Re: Multiwire Branch Circuit with Unequal OCP  
winnie  Offline
Member
Joined: Sep 2003
Posts: 649
boston, ma
I know that this is picking nits, but if you use a #8 Cu for a 20A circuit, wouldn't you also be required to use #8 for the EGC? *grin* Of course, given your normal work situation, I'm guessing that this circuit is in pipe.

-Jon


#89578 - 10/10/04 07:02 AM Re: Multiwire Branch Circuit with Unequal OCP  
iwire  Offline
Moderator
Joined: Jan 2003
Posts: 4,391
North Attleboro, MA USA
George, yes I have a white insulated grounded conductor. [Linked Image]

electricman2 That is my thinking too. [Linked Image]

Jon, I do not think you are nit picking, you are right on the money IMO.

If this was 8/3 MC cable the EGC would be 10 AWG which as you point out would be to small for the 20 amp circuit per 250.122(B)

This happens to be 8/3 AC cable, type AC cable does not have a copper EGC at all, it utilizes the armor as the EGC. [Linked Image]

Thanks for the replies

Bob


Bob Badger
Construction & Maintenance Electrician
Massachusetts


Member Spotlight
Niko
Niko
Campbell, CA
Posts: 356
Joined: August 2006
Show All Member Profiles 
Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.010s Queries: 14 (0.002s) Memory: 0.7688 MB (Peak: 0.9054 MB) Zlib enabled. Server Time: 2017-05-24 02:22:18 UTC