Stranded wire on receptacles

[steve66]

This goes back to another thread that's a few days old, but I keep wondering about this. (Bob, I hope you don't mind me quoting you from another thread.)

The NEC allows either stranded or solid and all 15,20 & 30 amp devices are listed for both stranded and solid.

I'm not sure I understand what you are saying. Does that mean stranded wire can be wrapped around the screw terminal on a standard receptacle?

I thought some type of spade lug was required to keep the strands from coming out from under the screw as its tightened. Or is that completely wrong?

Steve

 

[Dennis Alwon]

As someone pointed out not all devices will accept stranded but if they can then yes you can wrap the standed wire around the terminal of the device. A good trick is to strip the wire but don't remove the jacket until you wrap the wire around the screw. The jacket at the end of the wire will hold the strands together as you tighten the screw. Personally I don't like connecting stranded wire to devices unless they have a back stab that tightens with the screw , as in some Hubbell devices.

 

[jumper]

Twist the strands CCW and they will not splay out, but cinch tight.

 

[pete m.]

Twist the strands CCW and they will not splay out, but cinch tight.

:thumbsup:

Pete

 

[don_resqcapt19]

The following is from the UL Guide Information for Receptacles for Plugs and Attachment Plugs (RTRT).

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.

 

[renosteinke]

This is one area where UL and I have a difference of opinion. As far as I'm concerned, the lab geeks and engineering wonks have been sniffing too much solder on this one ...

IMO ... no matter what tricks you use, the screw heads of devices are terrible attachment points for stranded wire. "Back stabs" are not suitable for stranded wire at all. Only some form of clamp/pressure plate, one that helps contain the wire (rather than squeeze it out) is any good at all. Final result: the 'approved' methods don't do so well.

UL will tell you that no devices have been evaluated for use with any spade, fork, or ring terminals. Technically, that's true; it's not mentioned in their standard. There's also the practical matter that darn few such fittings will actually fit on the devices without something being modified. Still, I bet I could visit UL's own labs today and find numerous places where their own techs have used this method in the assembly of their test equipment. Final result: the 'unknown' method can work really well.

IMO, this is one time you want to forget 'code minimum' and actively select devices with better ways to land the wires.

 

[K8MHZ]

This is one area where UL and I have a difference of opinion. As far as I'm concerned, the lab geeks and engineering wonks have been sniffing too much solder on this one ...

IMO ... no matter what tricks you use, the screw heads of devices are terrible attachment points for stranded wire. "Back stabs" are not suitable for stranded wire at all. Only some form of clamp/pressure plate, one that helps contain the wire (rather than squeeze it out) is any good at all. Final result: the 'approved' methods don't do so well.

UL will tell you that no devices have been evaluated for use with any spade, fork, or ring terminals. Technically, that's true; it's not mentioned in their standard. There's also the practical matter that darn few such fittings will actually fit on the devices without something being modified. Still, I bet I could visit UL's own labs today and find numerous places where their own techs have used this method in the assembly of their test equipment. Final result: the 'unknown' method can work really well.

IMO, this is one time you want to forget 'code minimum' and actively select devices with better ways to land the wires.

I found that pig tailing the device with solid wire and then using a wire nut to connect the stranded and the solid together to be a decent option. I rarely see stranded wire under a plain screw terminal that looks like it's a good connection.

 

[iwire]

This goes back to another thread that's a few days old, but I keep wondering about this. (Bob, I hope you don't mind me quoting you from another thread.)



I'm not sure I understand what you are saying. Does that mean stranded wire can be wrapped around the screw terminal on a standard receptacle?

Yes.

As someone pointed out not all devices will accept stranded

Can you point out any 15, 20 or 30 amp devices that will not accept stranded?

 

[jumper]

I rarely see stranded wire under a plain screw terminal that looks like it's a good connection.

That's 'cause most people screw it up. It is pretty easy after you do it enough. Try the CCW twist, it works well.

 

[K8MHZ]

That's 'cause most people screw it up. It is pretty easy after you do it enough. Try the CCW twist, it works well.

Why not just use the other end of the pigtail?

If one end is clockwise, the other end has to be counter clockwise, doesn't it?

Edit....nevermind, I guess not....but that brings me to the question of why stranded wire isn't already CCW?

 

[steve66]

Our spec. program has a default paragraph that says "solid wire for #10 and larger". I thought it was because stranded wire needed spade lugs to terminate on the receptacles.

I'll probably change our spec. to allow solid or stranded.

 

[K8MHZ]

Our spec. program has a default paragraph that says "solid wire for #10 and larger". I thought it was because stranded wire needed spade lugs to terminate on the receptacles.

I'll probably change our spec. to allow solid or stranded.

Good call.

"310.3 Stranded Conductors

Where installed in raceways, conductors of size 8 AWG and larger shall be stranded."

 

[infinity]

Wish that this guy spent some time reading how to properly terminate stranded #10 conductors. We spent several hours trying to find the source of the IG connection to the mechanical ground. :rant:

 

[Dennis Alwon]

Can you point out any 15, 20 or 30 amp devices that will not accept stranded?

Not I but I thought someone did recently either here or at ET.

 

[cowboyjwc]

Just make sure your DON'T BACKSTAB IT!:happysad:

 

[jumper]

Wish that this guy spent some time reading how to properly terminate stranded #10 conductors. We spent several hours trying to find the source of the IG connection to the mechanical ground. :rant:

1. the strands are twisted CW.:happyno:

2. is that tape on a wirenout?:jawdrop:

 

[jim dungar]

Doesn't that brass pad lift up so it can trap stranded conductors?

 

[iwire]

Doesn't that brass pad lift up so it can trap stranded conductors?

I don't think so with that model. I think that brass is just the conductor heading into the device.

 

[hillbilly1]

I don't think so with that model. I think that brass is just the conductor heading into the device.

Kinda hard to tell without magnification, but it does look like a saddle that is turned wrong, so I believe it is a clamp.
(It does look like an IG receptacle, so it shouldn't be touching the mounting strap)

 

[jumper]

Kinda hard to tell without magnification, but it does look like a saddle that is turned wrong, so I believe it is a clamp.

Never saw a clamp/backwire on a EGC terminal for an IG: have you?