NFPA 79 - wire nuts in motor connection boxes

[steelerr]

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."

What I think this means that wire nuts cannot be used in motor 'potheads'. Other than European (CE-Marked) motors, I've never seen anything other than wire nuts with or without electrical tape wrap for making these connections.

Which US motor manufacturers offer terminal strips or connecting studs in the pothead?

Alternately, what "identified" methods exist for this conection? I'm having difficulty finding suitable connectors that won't cost a fortune to implement, or that will fit three into a typical pothead.

Thank you.


I see that my question was modified for Political Correctness. I've never heard the term pothead for a motor connection box. Some interesting comments on this subject were found here:
http://www.eng-tips.com/viewthread.cfm?qid=192982
Seems pothead is a Canadian term. I always thought that meant something else. Thanks.

{Moderator's Note: Edited to replace a word that some consider to be offensive.}

 

[LarryFine]

Alternately, what "identified" methods exist for this conection?

First thing that comes to mind is a set of split bolts.

 

[don_resqcapt19]

We use ring terminals, small machine screws and nuts, rubber and plastic tape for motor connections on smaller motors. For motors with more room in the motor terminal box we use Raychem GelCaps.
Don

 

[infinity]

Using the word pecker head to describe a motor connection box is no different than using the word nipple to describe a short piece of conduit. If pecker head isn't the word in question, I apologize.

 

[kc8dxx]

We use ring terminals, small machine screws and nuts, rubber and plastic tape for motor connections on smaller motors. For motors with more room in the motor terminal box we use Raychem GelCaps.
Don

Same here.

 

[steelerr]

Many thanks for the replies. We like the GelCaps, too. I've requested a sample.

 

[petersonra]

Interesting. Most industrial specs prohibit the use of wire nuts on machinery as they have a tendency to come off due to vibration. Split bolts or bolted ring tongue terminals don't come loose.

BTW, why is a ring tongue/bolt connection called a taco splice?

 

[steelerr]

In an effort to gain a variety of opinions in the electrical field and to generate discussion on the subject of industrial motor connection means, I posted this same question on another forum. If you're interested, here's a link to this engineering forum and the thread in question:

http://www.eng-tips.com/viewthread.cfm?qid=194533

Thanks again for your interest.

steelerr

 

[realolman]

Where I work there are thousands of fractional HP motors hooked up with wirenuts.

I do not know of any failures due to wirenut failure or coming off in 28 years.

I think they are less likely to short out than ring terminals, screws, and tape. The screws cause an irregular shape to tape up, and the tape isn't nearly as hard as the wire nut.

I remember hooking and unhooking fractional HP motors in the service with ring terminals and tape ... what a PITA. I think the European style with it's little terminals and double and triple nuts is another one.

Split bolts for big stuff.

 

[dlhoule]

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."

I've seen a number of suggestions on how to make these connections, but just where are these methods identified?