Wire nut use?

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red

Member
Location
Connecticut
I thought I heard or read some where that wire nut use on motor connections above a certain HP is restricted. Am I dreaming this or not?? I can't find anything in the code.
Thanks for any replys
Red
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
I'm sure once you get to a certain motor HP, the leads are going to be too big for wire nuts anyway.
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nonsense ! You can always cut enough strands out to get some size wirenut to work :grin:
 

480sparky

Senior Member
Location
Iowegia
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nonsense ! You can always cut enough strands out to get some size wirenut to work :grin:

What happens when the wires are solid?
mw_hmmm.gif


Or, you could start seperating the strands and break them down into smaller groups!
lightbulb.gif
 

elohr46

Senior Member
Location
square one
I thought I heard or read some where that wire nut use on motor connections above a certain HP is restricted. Am I dreaming this or not?? I can't find anything in the code.
Thanks for any replys
Red

It's common to see this in the job specs., especially on 480v motors. Crimp connections, mechanical bugs, rubber tape, varnished cambric, duct seal, & scotch 33 are some of the methods required.
 

buldogg

Senior Member
Location
Green Bay, Wisc.
In NFPA 79-2007, Clause 13.5.9.2 states, "Electrical connections at motor terminal boxes shall be made with an identified method of connection. Twist-on wire connections shall not be used for this purpose."
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
In NFPA 79-2007, Clause 13.5.9.2 states, "Electrical connections at motor terminal boxes shall be made with an identified method of connection. Twist-on wire connections shall not be used for this purpose."


Does the industrial machine standard apply to all motors?
 

buldogg

Senior Member
Location
Green Bay, Wisc.
Nonsense!!, I wired a 7 1/2 hp yesterday with big blues. And the original wirenut joint was 20 years old. If your connections are failing that often, you're doing it wrong.

The problem with wire nuts is that sometimes they are not properly installed. I have seen a couple of cases myself with motor terminations where the wire nut was umproperly installed and the wire nut failed (melted). Where I work, wire nuts for motor terminations are not allowed, even for fractional horsepower motors.
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
In NFPA 79-2007, Clause 13.5.9.2 states, "Electrical connections at motor terminal boxes shall be made with an identified method of connection. Twist-on wire connections shall not be used for this purpose."


How do you account for those 3phase motor taps with wire nuts installed from the factory?
 

mcclary's electrical

Senior Member
Location
VA
The problem with wire nuts is that sometimes they are not properly installed. I have seen a couple of cases myself with motor terminations where the wire nut was umproperly installed and the wire nut failed (melted). Where I work, wire nuts for motor terminations are not allowed, even for fractional horsepower motors.

I've worked in production plants for twenty years. I've changed hundreds of motors. Wirenuts are used the majority of the time on small motors. Some have ring terminals. Yes wire nuts will melt if installed wrong, but so will a ring terminal. so will a split bolt. anything installed wrong will fail.
 
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