Stranded wire .... Bare, soldered, Ferrule.....which?

[klaatu]

When dealing with stranded wire under a lug screw, what is best practice and what is permitted under NEC?
For example, simply use the stranded wire bare or add a ferrule to keep the strands together and less compressible, or solder the end to make it firm and bound and less compressible.

Several examples recently where the lug was torqued down, but many of the strands were not captured. Other instances where after torqueing and later removing, the wire was deformed and could not be reinserted, and had to be cut off. Which is okay, unless there no extra length.

 

[augie47]

"Standard" stranding (Chapt 9 Table 8) or fine strand (Chapt. 9 Table 10) ?

 

[infinity]

What is a lug screw? Is this a terminal or a binding screw on something like a receptacle?

 

[petersonra]

When dealing with stranded wire under a lug screw, what is best practice and what is permitted under NEC?
For example, simply use the stranded wire bare or add a ferrule to keep the strands together and less compressible, or solder the end to make it firm and bound and less compressible.

Several examples recently where the lug was torqued down, but many of the strands were not captured. Other instances where after torqueing and later removing, the wire was deformed and could not be reinserted, and had to be cut off. Which is okay, unless there no extra length.

Ferrules are not intended to be used on the type of screw terminals found on electrical receptacles. I would suggest a fork terminal instead.

I kind of agree that stranded wire is not ideal for terminating on these kind of screw terminals.

 

[don_resqcapt19]

Ferrules are not intended to be used on the type of screw terminals found on electrical receptacles. I would suggest a fork terminal instead.

I kind of agree that stranded wire is not ideal for terminating on these kind of screw terminals.

From the UL Guide for Receptacles for Plugs and Attachment Plugs (RTRT)

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.

There is only one model of receptacle from one brand that is so identified.

 

[4-20mA]

What is a lug screw? Is this a terminal or a binding screw on something like a receptacle?

I assume he means mechanical lug type.

They are typically wire size dependent. Sounds like it's pushing the limits on size or has the incorrect size even.

 

[ramsy]

There is only one model of receptacle from one brand that is so identified.

Only one model listed for fork terminals?

Plenty of devices w/ compression plates listed for stranded wire

 

[ramsy]

When dealing with stranded wire under a lug screw, what is best practice and what is permitted under NEC?

Always used listed crimp tool matched to listed fork terminal, but also seen field stripping methods that keep all strands under the terminal.

 

[augie47]

It is still not clear (to me) if you are addressing small conductors (`14-10) and screw terminals or larger conductors and pressure terminals.

 

[ramsy]

It is still not clear (to me) if you are addressing small conductors (`14-10) and screw terminals or larger conductors and pressure terminals.

It appears Klaatu has left the building. If interested, others must resolve this question without further direction

 

[LarryFine]

Klaatu barada nikto.

 

[rambojoe]

Klaatu barada nikto.

You said it wrong... and Jack left town!
I was thinking the same dang thing...
Shop smart.

 

[don_resqcapt19]

Only one model listed for fork terminals?

Plenty of devices w/ compression plates listed for stranded wire

Yes, one of the Hubble lines is identified for use with fork terminals. No others that I know of.

 

[tthh]

This forum is awesome....I have thought since I was a kid it was "varada"...I am learning something new every day.

 

[ramsy]

Yes, one of the Hubble lines is identified for use with fork terminals. No others that I know of.

Is that possibly listed for Aluminum fork terminals, which are typically sold everywhere, vs harder to find steal or copper terminals?

 

[ramsy]

This forum is awesome....I have thought since I was a kid it was "varada"...I am learning something new every day.

This is the exception and not the rule. Don deserves the credit for sharing this, not the forum.

Few can share details about listing requirements, much less provide referenced sources. Listings requirements are especially difficult to show, since standards are not free, and there's little incentive to put it in public domains, with often thankless trolls that cause more grief than reward.

 

[don_resqcapt19]

Is that possibly listed for Aluminum fork terminals, which are typically sold everywhere, vs harder to find steal or copper terminals?

No idea. Don't think I have ever seen aluminum fork terminals. The ones I use have always been tin plated copper.

 

[don_resqcapt19]

This is the exception and not the rule. Don deserves the credit for sharing this, not the forum.

Few can share details about listing requirements, much less provide referenced sources. Listings requirements are especially difficult to show, since standards are not free, and there's little incentive to put it in public domains, with often thankless trolls that cause more grief than reward.

Actually all of the UL Standards can be viewed using the same non-user friendly system that the NFPA uses for their free viewing. You just have to register with an e-mail address.

 

[stretch12]

Klaatu barada nikto.

Army of darkness! , thank you

 

[klaatu]

What is a lug screw? Is this a terminal or a binding screw on something like a receptacle?

It was just in general, but had 4AWG that was mangled by the lug screw, had to cut off the bad section, could not be saved