Stranded and Solid wire mixed?

[Gregdoo]

Hopefully a quick, simple question. I'm remodeling my house and rewiring some rooms. House was built in the 60s and was done with EMT conduit throughout. I bought some spools of THHN wire on Craigslist and ended up with 500' of black solid and 500' of green and white in stranded. Is it permissible to run a circuit with this combination of stranded and solid wires? If so, is there any concern or downside that I need to be aware of? I do have a permit and all work needs to pass code inspection. Thanks.

 

[Aceman]

It's weird and I've never done it, but legal. So you're good to go.

 

[malibu101]

Just be sure to use the right kind of devices. You must use devices that have the compression plates that squeeze the stranded wire. I don't think it's code legal (and it is REALLY ugly if you try) to make a "U" bend on the end and put it under a screw like you can with solid wire. Or you can squeeze Sta-Kons on the end of the stranded to attach to the devices if they only have a screw.

 

[Gregdoo]

Thanks to both of you. Malibu, when you mention compression plates, I'm thinking my recepticles are OK......they allow "back wiring"....not the older "back stab", but the ones that look similar, where you poke the wires in the back and tighten the side screw to secure the wire via a small plate inside the recepticle. Are these acceptable with stranded? I couldn't find a picture.....Friday afternoon Google-fu is weak.

 

[Norcal]

Just be sure to use the right kind of devices. You must use devices that have the compression plates that squeeze the stranded wire. I don't think it's code legal (and it is REALLY ugly if you try) to make a "U" bend on the end and put it under a screw like you can with solid wire. Or you can squeeze Sta-Kons on the end of the stranded to attach to the devices if they only have a screw.

Just a little note, ALL wiring devices are listed for solid or stranded conductors but the Sta-Kons® are not listed for use w/ the wiring devices.

 

[kngelv]

I would not run the solid through conduit. Not sure how many degrees the bends are or the conduit size but you could run into trouble when pulling the wire. Legal . . . yes. Smart . . . no.

james

 

[malibu101]

Thanks to both of you. Malibu, when you mention compression plates, I'm thinking my recepticles are OK......they allow "back wiring"....not the older "back stab", but the ones that look similar, where you poke the wires in the back and tighten the side screw to secure the wire via a small plate inside the recepticle. Are these acceptable with stranded? I couldn't find a picture.....Friday afternoon Google-fu is weak.

Yes. That's what I am talking about.

Just a little note, ALL wiring devices are listed for solid or stranded conductors but the Sta-Kons® are not listed for use w/ the wiring devices.

I did not know that about Sta-Kons. Thank for the info!
I find it odd that putting stranded under a screw is good. It usually gets squeezed out more than I'd like doing that.
I use mainly Hubbell outlets.
A CR15I is screw only.
A 5252AI has the "wire clamp" that I like. I 99% of the time use these.

 

[mtne]

I would not run the solid through conduit. Not sure how many degrees the bends are or the conduit size but you could run into trouble when pulling the wire. Legal . . . yes. Smart . . . no.

james

Huh?!? 12awg and smaller I prefer solid. Much easier to work with and pull.......... and I've pulled miles of it.

"sure we've got a tugger............. he cubby, get over here....."

 

[buzz4041]

90% of light commercial installation are done in EMT with solid wire for all of the lighting and outlet circuits. Pulling solid is no problem.

 

[Norcal]

I would not run the solid through conduit. Not sure how many degrees the bends are or the conduit size but you could run into trouble when pulling the wire. Legal . . . yes. Smart . . . no.

james

Your allowed 360° of bends in a run, (Or between pull points), this includes offsets, & applies to any type of wire, solid is only allowed in 10 AWG & smaller in a conduit.

 

[kngelv]

Your allowed 360° of bends in a run, (Or between pull points), this includes offsets, & applies to any type of wire, solid is only allowed in 10 AWG & smaller in a conduit.

I know this, but . . . you would not believe how many times I've seen more. I had to wire some outlets in a welding booth a few weeks ago. The conduit was put up by some midnight shift knuckle head. I kid you not . . . 495 DEGREES. I had to rip half of it down. Hell, he could have put a C in the middle and been ok.

James

 

[Aceman]

I know this, but . . . you would not believe how many times I've seen more. I had to wire some outlets in a welding booth a few weeks ago. The conduit was put up by some midnight shift knuckle head. I kid you not . . . 495 DEGREES. I had to rip half of it down. Hell, he could have put a C in the middle and been ok.

James

So what do this have to do with you not recommending solid wire in conduit?

I would not run the solid through conduit.

 

[kngelv]

So what do this have to do with you not recommending solid wire in conduit?

Just a personal preference.

James

 

[Charles (in GA)]

I've pulled a lot of solid in my EMT piped 60x60 shop and never had a real problem. I'm doing this by myself, so I pull some, walk to the wire spools, lube some, walk back and pull some, but if I had help it would be no effort at all.

In properly installed EMT, if you cannot pull 12 solid, you must be a 90 pound weakling. Stranded is more difficult to work with on the ends. requires much more care in the terminations, that you don't have strands that don't get in the switch, receptacle, etc, and its practically impossible to get a good wrap around a screw with stranded. I backwire when I can, but some switches don't allow for it.

Charles

 

[rburke65]

The trick with using stranded wire under the screws of a switch or a receptical, so the wire strands don't squeeze out while you are tightening the screw is this......the strands of the wire are wound clock wise from the factory. After stripping back the insulation, twist the stranded wire "Counter Clockwise", then form it under the screw in a clock wise direction, and tighten the screw and the strands will now be pulled under the screw head, rather than being pushed out! Try it.... You'll like it!

 

[Gregdoo]

Appreciate all the comments and especially the tips on how to handle stranded terminations. The new outlets are all backwired, and relatively easy. The ground screws are not, so I'll try the "reverse twist" recommendation. I'm only dealing with 14 and 12 gauge wires and haven't had issues with pulling solid (yet). The hardest part is determining where each wire goes ("intermediate terminations"). I have a bedroom that is at the opposite end of the house, and I'm wanting to pull 12 gauge to the master bath (using the existing 14 gauge as the pulling wire); I have pulled off about every coverplate and recepticle between the panel and bathroom and still can't seem to figure out the routing to get there. Probably doesn't help that I have low-voltage (Touchplate) switching for lights. I'm sure there must be some sort of device that would make it easier to track the wires, but I'm not sure what it is.