Landing stranded wire on screw terminals

Status
Not open for further replies.
Dave047 said:
By definition stranded wire is a flexible connection. Does the code not require flexible connections to be terminated with a terminal ( sta-kon) connection on a screw unless the screw is rated for this( i.e. a breaker terminal screw)
Click to expand...

110.14(A)(A) Terminals.
Connection of conductors to terminal parts
shall ensure a thoroughly good connection without damag-
ing the conductors and shall be made by means of pressure
connectors (including set-screw type), solder lugs, or
splices to flexible leads. Connection by means of wire-
binding screws or studs and nuts that have upturned lugs or
the equivalent shall be permitted for 10 AWG or smaller
conductors.
 
Dave047 said:
By definition stranded wire is a flexible connection. Does the code not require flexible connections to be terminated with a terminal ( sta-kon) connection on a screw unless the screw is rated for this( i.e. a breaker terminal screw)
Click to expand...
The UL Guide information (white book) for "Receptacles for Plugs and Attachment Plugs (RTRT) specifically states that the screw terminals on listed receptacles are suitable for use with stranded conductors.
Terminals of the wire-binding screw, setscrew, or screw-actuated back-wired clamping types are suitable for use with both solid and stranded building wires.
Terminals of a receptacle are permitted for use with certified field-installed crimped-on wire connectors or an assembly, if so identified by the manufacturer.
Click to expand...
However the information in the white book for "Snap Switches (WJQR) does not read the same even though the screw terminals on the switches and receptacle appear to be of the same design.
Terminals of the wire-binding screw, setscrew, or screw-actuated back-wired clamping types are suitable for use with solid building wires unless otherwise indicated either on the device or in the installation instructions.
Terminals of a flush snap switch are permitted for use with Listed field-installed crimped-on wire connectors or an assembly, if so identified by the manufacturer.
Click to expand...
 
stranded wire around rec. screw.

stranded wire around rec. screw.

Dave047 said:
By definition stranded wire is a flexible connection. Does the code not require flexible connections to be terminated with a terminal ( sta-kon) connection on a screw unless the screw is rated for this( i.e. a breaker terminal screw)
Click to expand...

Sorry should clarify a little. Most manufacturer's written installation instructions call for solid wire only. ( I just looked at two manufacturers websites for standard grade recs. 15 amp) I am an electrical inspector and work with approx. a dozen other electrical inspectors. A quick poll of a few said unless you can show them written install instructions that allow stranded wire, they will turn down stranded wire wrapped around a receptacle screw every time tinned or not. You are going against product listing / labeling.
 
Last edited:
Dave047 said:
http://www.leviton.com/OA_HTML/ibcG...5NSpIzAA&label=IBE&appName=IBE&minisite=10251

Here is leviton's wiring instructions for a T5325-E Decora duplex rec., nothing fancy. note 3
Click to expand...

That is consistent with the Code language that allows stranded for side screws and for pressure plate type back connections.
Note 3 allows stranded for the side wire screws but does not allow it for the backstap rear connections, which are NOT pressure plate type (no mention of loosening the screw first and tightening it after.)
 
GoldDigger said:
That works, thanks.

Hardly a typical receptacle though, and it also does not accept #10. :)
Another case where the manufacturer's instructions can prohibit something that the Code permits in general.
The other direction of manufacturer's instructions permitting something prohibited by Code does not work as well. :)
Click to expand...

Note #2 is interesting as well. 5/8" strip for wrapping around the screws isnt enough - back wire, sure, but unless that receptacle has smaller than avg diameter screws, nope.
 
stranded wire on rec screw

stranded wire on rec screw

GD go back and read note 3 again.( T5325-E ) It DOES NOT allow for stranded wire at all. The side wire instructions call for solid as well.
 
Dave047 said:
GD go back and read note 3 again.( T5325-E ) It DOES NOT allow for stranded wire at all. The side wire instructions call for solid as well.
Click to expand...
OK. I went back and read it.

From the PDF, for sidewire: "Terminal screws accept up to #12 AWG copper or copper clad wire." No mention of solid or stranded.
For Quickwire™ (backstab): " Quickwire™ terminals accept #14 AWG solid copper or copper clad wires ONLY!

Do you see the same difference that I did? Or are you looking at a different version of the PDF?
 
GoldDigger said:
OK. I went back and read it.

From the PDF, for sidewire: "Terminal screws accept up to #12 AWG copper or copper clad wire." No mention of solid or stranded.
For Quickwire™ (backstab): " Quickwire™ terminals accept #14 AWG solid copper or copper clad wires ONLY!

Do you see the same difference that I did? Or are you looking at a different version of the PDF?
Click to expand...

Continued:

If you are thinking of the later statement
" For circuits with #12 AWG solid copper or copper clad wires, use terminal screws instead.", that refers to solid only because if you had #12 stranded you would already be forced to use the terminal screws by the original part of the Quickwire™ instructions.
 
Not reading all the Post .



I strip the wire , then strip some more and leave the insulation on the end of stranded wire .


Make eye around screw and tighten .


Never had a problem .




Don
 
Dave047 said:
I am an electrical inspector and work with approx. a dozen other electrical inspectors. A quick poll of a few said unless you can show them written install instructions that allow stranded wire, they will turn down stranded wire wrapped around a receptacle screw every time tinned or not. You are going against product listing / labeling.
Click to expand...
Wow, get a bunch of inspectors together and it is worse than a sewing circle! :D

Forget the consensus rumor mill at the inspectors circle and re-evaluate what you think you know because the dozen of you are simply wrong. Better to correct it now than to keep propagating wrong info. Now the fun part will be convincing your buddies they have been doing it wrong.:)
 
ActionDave said:
Yes it does. The recpt can't meet UL unless the screws are suitable for stranded conductors. GoldDigger is correct.

What they are not listed for is crimped on connectors.
Click to expand...
That is how I read the UL Guide Information for receptacles. That the requirement that the screws be suitable for use with stranded conductors is part of the listing standard.
 
Status
Not open for further replies.
Top