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!


2017 NEC and Related
2017 NEC
Now Available!

Recent Posts
Parking lot pole light swap....
by ghost307
49 minutes 28 seconds ago
International Wire Colour Codes
by Tjia1981
Yesterday at 12:08 PM
Son of Sparky
by HotLine1
10/20/16 07:43 PM
Speaking of Plugmold ...
by gfretwell
10/17/16 02:37 PM
Broken battery charger? Check for cobwebs!
by gfretwell
10/17/16 02:30 PM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 13
HotLine1 7
ghost307 7
renosteinke 6
Potseal 4
Who's Online
1 registered (Tjia1981), 252 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#194635 - 06/14/10 12:44 PM 6/3 NMWU amperage rating?
mr_electrician Offline

Registered: 06/22/07
Posts: 106
Loc: London, Ontario
Correct me if I am wrong but since NMWU has a 60 degree rating, then #6NMWU is only good for 55Amps unless it is part of a residential service? (T.2 of the OESC) I am guessing that a sub panel to the garage would not fall under this classification therefore limiting my amperage rating to 55amps and not 60?
Never trust an electrician with no eyebrows!!

2014 / 2011 NEC & Related Books and Study Guides
#194641 - 06/14/10 05:06 PM Re: 6/3 NMWU amperage rating? [Re: mr_electrician]
mikesh Offline

Registered: 06/07/06
Posts: 614
Loc: Victoria, BC, Canada
I think that as long as the Garage is a residential garage and part of a single residential unit, then 60 amps would apply. A residential Garage is not a continuous load and residential services are non continuous loads.
A duplex with a single joint use garage might not qualify.

Talk to the local authority but I think we would allow the greater ampacity as long as the Volt drop does not get rediculous.

#194692 - 06/15/10 10:33 PM Re: 6/3 NMWU amperage rating? [Re: mikesh]
twh Offline

Registered: 03/11/04
Posts: 895
Loc: Regina, Sask.
Isn't it a 55 amp feeder fused at 60 amps per Table 13? The differences are that if the load in the garage is greater than 55 amps, the wire is too small; and, the location of the panel in the garage isn't restricted like a residential service.

#197138 - 11/10/10 06:00 PM Re: 6/3 NMWU amperage rating? [Re: twh]
swoop Offline
New Member

Registered: 10/24/10
Posts: 9
Loc: ontario
good luck finding a 55 amp breaker

#197160 - 11/12/10 11:19 AM Re: 6/3 NMWU amperage rating? [Re: swoop]
mikesh Offline

Registered: 06/07/06
Posts: 614
Loc: Victoria, BC, Canada
Yes you make the most important point. As long as the calculated load is less than 55 amps then the #6 is good and table 13 would allow a 60 amp breaker.


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