Stranded wire on outlets

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Srv52761

Srv52761

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I have used 12# and 10# stranded wire for decades for special cases.
If I am approaching max box fill, I like stranded as I think it is easier to fold.
When I have to bump up to #10 because of adjustment for number of conductors and I have a lot of turns, I think stranded is easier to pull.

Back in the day when connecting to an outlet, before the current side clamps, I would strip an extra 1/2" of insulation, twist the strands counterclockwise, wrap around the screw, tighten, wiggle, tighten again, trim off the excess. The twist and extra length would keep the strands tight to the screw.

Just today, an acquaintance who works with audio and video systems and almost exclusively with stranded said this was wrong. Stranded should never be wrapped around a screw.

Can/should stranded be wrapped around a screw?
If yes, is my technique acceptable?
 
stranded, I always do CCW. ( I also don't leave that little piece of insulation on the end as I see others do ).
 
Quick question..
Was he suggesting a spade or fork termination?
Receptacles aren’t listed for spade terminals IIRC..
 
I leave a tail of insulation sticking off the end, and pinch around the screw with my strippers.

Never heard of twisting ccw 🤔
I'll have to try that next time.
 
infinity said:
Either method is permitted but IMO the fork terminal is better.
Click to expand...

The way I read this is they are permitted if the manufacturer identifies the unit as accepting a field installed crimp on connector.
If the manufacturer doesn’t list it or identifies the receptacle for use with a crimp on spade then no, IMO.

Correct? Or am I missing something here..

From the UL white book 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.
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.
A receptacle may also be provided with conductor leads with factory- installed crimped-on connectors. Such connectors may be either attached to the receptacle terminal or are provided with the receptacle in the small- est unit shipping container and are suitable for use with the terminal of the receptacle.

Edit.. just saw this..
It’s a little old but I don’t THINK it’s changed.. may have, I don’t have a current copy

iaeimagazine.org

Are receptacles and switches Listed for use with stranded conductors? - IAEI Magazine

Question: Stranded conductors on receptacles and switches I was always told that you could not use stranded conductors on receptacles and switches without crimping a spade terminal onto the stranded conductor and then securing the spade terminal onto the device screw terminals. Are receptacles...
iaeimagazine.org iaeimagazine.org
 
Hv&Lv said:
The way I read this is they are permitted if the manufacturer identifies the unit as accepting a field installed crimp on connector.
If the manufacturer doesn’t list it or identifies the receptacle for use with a crimp on spade then no, IMO.

Correct? Or am I missing something here..

From the UL white book 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.
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.
A receptacle may also be provided with conductor leads with factory- installed crimped-on connectors. Such connectors may be either attached to the receptacle terminal or are provided with the receptacle in the small- est unit shipping container and are suitable for use with the terminal of the receptacle.

Edit.. just saw this..
It’s a little old but I don’t THINK it’s changed.. may have, I don’t have a current copy

iaeimagazine.org

Are receptacles and switches Listed for use with stranded conductors? - IAEI Magazine

Question: Stranded conductors on receptacles and switches I was always told that you could not use stranded conductors on receptacles and switches without crimping a spade terminal onto the stranded conductor and then securing the spade terminal onto the device screw terminals. Are receptacles...
iaeimagazine.org iaeimagazine.org
Click to expand...
Can you give me an example of a certified crimped on wire connector? I don't see a definition of certified in the NEC.
 
K8MHZ said:
Can you give me an example of a certified crimped on wire connector? I don't see a definition of certified in the NEC.
Click to expand...
I have no idea what that would be either.

I was failed on an installation about 8 years ago using forks.
I argued and the inspector threw up all this crap at me about UL and 110.3 or something like that.

I had to cut the forks off and wrap the strands.
I swear it seemed to me the stupidest thing an inspector ever made me do..

I’ll admit I’ve failed on my own for some stuff that was legitimate such as box fill and one for GFCIs in a shop right after a code change.
The forks one really got under my skin..
 
Hv&Lv said:
The way I read this is they are permitted if the manufacturer identifies the unit as accepting a field installed crimp on connector.
If the manufacturer doesn’t list it or identifies the receptacle for use with a crimp on spade then no, IMO.

Correct? Or am I missing something here..
...
Click to expand...
You are correct and there is only one Hubbell receptacle model that is so identified. I don't remember the exact part number.
 
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