crimp connector size for THHN 12G

[yeldogt]

I'm trying to order some fork type crimp connectors -- I need the yellow for 12g but they come in different sizes ... 6/8/10 ... the 6 look too small but I can't figure out what a typical outlet and switch requires ... the 8 or 10.

I'm replacing devices and repairing the wiring around the outside of my house -- its all 12g stranded THHN/W wire in conduits with fork/spade connectors at each device.

 

[MattT]

It's #8 screw size you need. The other thing to watch is the overall width of the fork. Some are too wide.

 

[yeldogt]

It's #8 screw size you need. The other thing to watch is the overall width of the fork. Some are too wide.

Thanks -- did not think it would be so difficult.

 

[sberry]

Just cause someone else used then doesn't mean you have to. I am not really sure it's a great idea, probably ok with light loads. This might be interesting to hear about from some with minds greater than our own?

 

[ishiboo]

It's unconventional in household wiring, but the terminals are UL rated. I see a lot of them in boats AC systems but those use more finely stranded conductors than THHN/THWN.

I prefer to use the outlets with the backwire screw clamp for stranded.

 

[yeldogt]

Just cause someone else used then doesn't mean you have to. I am not really sure it's a great idea, probably ok with light loads. This might be interesting to hear about from some with minds greater than our own?

It seems to be the way people do it with stranded wire in conduit -- have a proper crimper. Stranded under the screw seems more problematic.

Agree ........the back wire looks like a good idea -- may do a search for outlets w/ stranded capabilities. The spec grad switches from Lev .. don't have.

All the premade pigtails are crimp.

 

[cbacres]

I'm not the expert here by far, but I'm pretty sure crimped connectors are not to code for building wiring.

 

[sberry]

I have put 1000s of stranded under screws, twist the strands left handed before wrapping on the screw.

 

[nanofrog]

Another vote for the Leviton 5252 screw & clamp backwire model (see ishiboo's photo).

They're rated for both solid and stranded wire, so you'll get a proper connection without any special tooling.

 

[theoldwizard1]

Side clamps are fantastic !

 

[alfredeneuman]

I'm not the expert here by far, but I'm pretty sure crimped connectors are not to code for building wiring.

Most are....some are not (usually used for automotive wiring)
Most are rated @ 600V. When would you run into 600V except in building wiring?

 

[sberry]

Where I really like backwire is on old work replacement where boxes are small. A guy can set it up, train it all to fold back in and don't need pigtails. I very rarely double side wire for power beyond, did it on a service call the other day where there was a failed backstab.

 

[yeldogt]

The crimps are code -- checked just to be sure nothing changed. With the correct crimper it's actually not that time consuming.

I agree that reverse twist on the wire is better -- it's still pain for me to do it with 12g wire Everything is 12g stranded wire.

The problem I have is that many of the devices have rusted screws and I have damaged some of the crimps trying to remove.


Leviton 5252 look like a nice solution for the outlet issue -- just ordered a box of 10 for $30 bucks on ebay.