grounding with #10 stranded

[monkey]

When grounding a 1900 with stranded wire is it permissable to use a washer under the 10/32 screw head to keep the strands from coming out from under the screw head? Thanks

 

[mdshunk]

I do not know the answer to your question, but I do offer this suggestion. Pretwist the stranded bundle counter-clockwise before you wrap it around the screw. That will solve your problem. For some reason, twisting the bundle of strands counter clockwise (backwards from the installer's natural tendancy) seems to keep all the hairs under the screw head. Ground screws are 'hex washer head' to begin with. Premanufactured ground pigtails have a spade terminal crimped on them. That is another possibility.

 

[John Valdes]

is it permissable to use a washer under the 10/32 screw

is it permissable to use a washer under the 10/32 screw

Tip, With wire strippers start about 3" from end of wire. Start the strip, but do not allow the insulation to be completely removed. Leave enough wire exposed to wrap the screw clockwise. The insulation left on the end will keep the strands from unraveling. I do this on recpt's too whenever I am using stranded wire. Make sure to push the end's around back of the recpt for easy and safe installation. However, if the wire is large, I would use a terminal and crimp on. The washer sounds okay to me. But I also am not sure.

 

[mdshunk]

I got to thinking about this washer deal. A couple of thoughts come to mind... 1) nobody else seems to have any special problems not using a washer, and 2) There are washers for this purpose. They often come under the ground screws on fixture bars. They are normally brass, and have a "cupped" area in which to contain the strands. It took a little digging, but I think I found the original patent for this washer type:

http://www.google.com/patents?vid=USPAT2326090&id=oPRjAAAAEBAJ&pg=PP1&dq=washer+stranded+conductor#PPP1,M1

 

[paul]

I find these to be quite useful.

 

[tallgirl]

Tip, With wire strippers start about 3" from end of wire. ...

Is that a typo? I start about 1" from the end, strip about 3/4", then trim the excess insulation off, leaving about 1/4" of insulation to keep the strands together. Then, I grab that piece of insultation, squeeze, and give the wire a good twist to "tighten up" the strands, before finally screwing it to whatever.

 

[roger]

Julie, as far as an EGC or an EBJ is concerned, you could start stripping anywhere, even where it leaves raceway or cable connector.

Roger

 

[Dave58er]

Is that a typo? I start about 1" from the end, strip about 3/4", then trim the excess insulation off, leaving about 1/4" of insulation to keep the strands together. Then, I grab that piece of insultation, squeeze, and give the wire a good twist to "tighten up" the strands, before finally screwing it to whatever.

I have tried it this way and it just doesn't work for me.
I start way back on the wire.
For one thing if I just leave 1/4" of insulation it always comes off when I do the back-twist thing that Marc talked about, then I'm just starting over.

Also I strip a good 1 1/2" because half the time you tighten the screw and the wire will "roll" a bit so that if you only strip 3/4" you are left with some insulation under the screw. Once again, just back to starting over.

I'm sure I could get your way to work if I was being a little more patient and carefull but I'd rather give myself a margin for error. The only time I wrap a ground is on the plate for lay-in light fixtures, and with sometimes hundreds of fixtures I'm in a hurry and I don't want to do any twice.

I use a sta-kon or a ground tail and wire-nut for pretty much anything else.

 

[John Valdes]

No typo, I like alot of room (empty insulation). I can't say for sure where I start but it is more than 1.5 inches. Then I can cut off any excess.

 

[celtic]

For one thing if I just leave 1/4" of insulation it always comes off when I do the back-twist thing that Marc talked about, then I'm just starting over.

You do one or the other...doing both is a waste of time - unless you like making yourself angry.

Me, I strip it and twist 'em "backwards".
I never liked the dangling chad

 

[romeo]

grounding with #10 stranded

I find these to be quite useful.

Well said Paul, Hey guys there are connectors made for the purpose of terminating stranded conductors. I am almost sure that is a code section requiering them unless turned up terminations are used, sorry I can't look the section up now

 

[cpal]

110.14 (A) Terminals. Connection of conductors to terminal parts
shall ensure a thoroughly good connection without damaging
the conductors and shall be made by means of pressure
connectors (including set-screw type), solder lugs, or
splices to flexible leads. Connection by means of wirebinding
screws or studs and nuts that have upturned lugs or
the equivalent sall be permitted for 10 AWG or smaller
conductors.
Terminals for more than one conductor and terminals
used to connect aluminum shall be so identified.


This might be the section you are thinking of ????

 

[tallgirl]

I have tried it this way and it just doesn't work for me.
I start way back on the wire.
For one thing if I just leave 1/4" of insulation it always comes off when I do the back-twist thing that Marc talked about, then I'm just starting over.

Oy, yes, that would be annoying.

I don't understand how the insulation is coming off -- you grab the insulation with your fingers, squeeze and twist and it comes off, or it comes off when you put the wire under the screw, or ... ? I'm not trying to twist it backwards like mdshunk, I just undo whatever untwisting was done when the wire was stripped. That's probably a big difference.

Also I strip a good 1 1/2" because half the time you tighten the screw and the wire will "roll" a bit so that if you only strip 3/4" you are left with some insulation under the screw. Once again, just back to starting over.

I'm sure I could get your way to work if I was being a little more patient and carefull but I'd rather give myself a margin for error. The only time I wrap a ground is on the plate for lay-in light fixtures, and with sometimes hundreds of fixtures I'm in a hurry and I don't want to do any twice.

Well, I'm seldom in a hurry!

I am getting better, however -- the group I've been working with of late is several retired union electricians and they've been teaching me a thing or three.

 

[monkey]

I do leave a bit of insulation on the end, but it still squashes out. I knew about the back twisting but I didn't really try it, I'll try that. If that doesn't work, I'll use the forks.

 

[ibew441dc]

monkey,

I would caution the use of just any type of washer for this purpose. There are washers that are manufactured for this purpose.

An AHJ might throw 250.8 at ya and say the washer (assuming fender or flat)
is not listed for grounding/bonding.

I know thats splitting hairs but I have met inspectors who are picky like that.

ibew441dc

 

[acrwc10]

This may sound simple, Try getting a solid piece of wire for the ground screw and make your own pig tail.

 

[e57]

Julie, as far as an EGC or an EBJ is concerned, you could start stripping anywhere, even where it leaves raceway or cable connector.

Roger

I have tried to train guys under me not to do that - common practice - as I see it as a violation of 300.14. They strip it right out of the entry and then right to the screw, and that counts as a termination IMO.

On topic, if worried about stranded - pigtail a piece of solid...

 

[hardworkingstiff]

I'm with Paul.

 

[infinity]

monkey,

I would caution the use of just any type of washer for this purpose. There are washers that are manufactured for this purpose.

An AHJ might throw 250.8 at ya and say the washer (assuming fender or flat)
is not listed for grounding/bonding.

I know thats splitting hairs but I have met inspectors who are picky like that.

ibew441dc

He could use a screw not listed for grounding so why would the washer matter?

 

[roger]

I have tried to train guys under me not to do that - common practice - as I see it as a violation of 300.14. They strip it right out of the entry and then right to the screw, and that counts as a termination IMO.

On topic, if worried about stranded - pigtail a piece of solid...

Mark, there are different opinions on this, but even if you strip the conductor back to the connector you can still leave the required length (depending on opinion) before the termination and left over insulation.

Roger