# Butt splices into circuit breakers



## sespllc (Nov 2, 2010)

I have a contractor that would like to use butt splices to terminate fine stranded cable into breakers....it has been suggested that they use the proper CE or UL listed crimp-on connectors, but to meet schedule they recommend using butt splices since they are onsite...I do not use these as a matter of course, but, is there a precedence for this application of butt splices?


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## SparkYZ (Jan 20, 2010)

What size wire/ circuit breaker size?


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## TOOL_5150 (Aug 27, 2007)

Depending on the wire size, I may be inclined to use polaris gray. They are made for fine stranded wire. As long as you have the room, of course.

~Matt


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## hardworkingstiff (Jan 22, 2007)

sespllc said:


> I have a contractor that would like to use butt splices to terminate fine stranded cable into breakers....it has been suggested that they use the proper CE or UL listed crimp-on connectors, but to meet schedule they recommend using butt splices since they are onsite...I do not use these as a matter of course, but, is there a precedence for this application of butt splices?


I assume you mean a THHN (or similar) conductor will be butt spliced to the fine stranded cable. I see nothing wrong with this as long as the butt splice is rated for both cables AND the crimp tool is listed for the butt splice and the two different cables.


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## 480sparky (Sep 20, 2007)

I thought engineers where supposed to be superior than dumb old electricians. :001_huh:


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## nrp3 (Jan 24, 2009)

Why do this?


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## 76nemo (Aug 13, 2008)

480sparky said:


> I thought engineers where supposed to be superior than dumb old electricians. :001_huh:


 
Why the splice? Did the double E miscalculate length? Why the switchover? I personally do not like butt splicing. If it's not prone to vibration and properly done, who am I to say??????


Just don't like it...........


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## brian john (Mar 11, 2007)

If this is locomotive cable you need to check the listing of the connector to verify it is suitable for multi-strand.

An Ilsco SPA, SPRA might be an alternative

https://www.ilsco.com//ProductsDeta...=eSjnb7q+gv3uVEWig3FvcgsmSrKAZyhfEFyRqFBrhXQ=


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## hardworkingstiff (Jan 22, 2007)

nrp3 said:


> Why do this?


Most lugs are not rated to have fine stranded wire terminate on them. It's known to a point of failure.


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## brian john (Mar 11, 2007)

hardworkingstiff said:


> It's known to a point of failure.


I do not doubt this but you have made a statement can you back it up with legitimate proof?


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## hardworkingstiff (Jan 22, 2007)

brian john said:


> I do not doubt this but you have made a statement can you back it up with legitimate proof?


I don't know if you call this proof, but from this site:
http://www.nmsu.edu/~tdi/pdf-resources/IAEI-1to2-05.pdf


> With no marking or factory
> literature/instructions to the contrary, the terminal may
> only be used with conductors with the most common
> Class B and C stranded conductors. Th ese terminals
> ...


Or from this site:
http://www.nmsu.edu/~tdi/pdf-resources/pdf version divided PV:NEC/APPENDIX K.pdf



> Reports have been received over the last several years about field-made connections that have
> failed when flexible, fine-stranded cables have been used with mechanical terminals or lugs that
> use a set screw to hold the wire in the terminal.


And


> Since the Perspectives on PV article on fine stranded cables was published in the January-February issue of the IAEI News, I have received calls from people in other industries about connections failing where fine stranded cables have been used improperly. These failures have been associated with electric vehicle power cables, motor connections, and a few other high-current applications.


 from this site: http://www.iaei.org/magazine/?p=1976


Is that legitimate/sufficient?


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## wwilson174 (Apr 25, 2008)

hardworkingstiff said:


> I don't know if you call this proof, but from this site:
> http://www.nmsu.edu/~tdi/pdf-resources/IAEI-1to2-05.pdf
> 
> 
> ...


Clearly convincing in my view. BillW


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