ECN Forum
Folks,
I ran into a situation today which you may symphasize with. I was pulling wires through a L E Mason, Red Dot condulet and there is a sharp cornerinside the LB and it was scraping insulation from my wires. Two white wires ended up with bare copper showing. I don't know why tthe company buys this junk and why Thomas & Betts produces it. [They also have the obsolete straight slotted screws.]
Has anyone else experienced this problem?
~Peter
I'm sure your company is very proud of your workmanship and helping them see a profit.

Dave
Does your buyer in fact know that it's junk? Generally, all he knows is what the catalog says about it, and what the price quote is. I've never seen a catalog page that says, "This stuff is junk." If nobody tells him that it's no good, he'll just keep buying it, assuming that it's OK.
S/Powered,
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I've never seen a catalog page that says, "This stuff is junk."
Can't say I have either, but I'm all for honesty when it comes to product descriptions.
[Linked Image]
yep, 300 foot pull of twin sets 3/0 copper, 8 wires total, pulled both directions from center point by hand through multiple bend, lb, trough, anything on the shelf. last 40' skinned 2 wires like mad. 4 rolls of 33+ later and some white tape to make them neutrals and we were done. NOT my idea
Regardless of the length of pull,
I'd recommend the prolific use of Lube.
Cable lube is a wholly under-stated thing, sure it will not help with sharp edges, but it will help with a long pull.
As an Electrician, I check all of the surfaces, (mainly bends) that I will be pulling through, for smoothness.
Anything that has a sharp or even coarse edge, gets the file treatment.
Having cables or wires blow out within a conduit, because of poor installation here is looked upon as very bad practice.
I expect it is the same in the US?.
What size conduit?
What was the max size and nuumber of conductors marked on the LB?
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What was the max size and number of conductors marked on the LB?

That is a real consideration.

A typical LB can not hold the same number of conductors as the raceway it is connect to.

A typical problem I run into is 225 amp feeders. We can run four 4/0 in 2" EMT but the 2" EMT LB is labeled as three - 4/0s max.

By the way TKB, how is BU I hear you have been a great help there and other places. [Linked Image]

Bob
Bob,
I think BU is finished, but the S&S nights were tough.
I like being on my own, but sometimes I miss the big machine.
Like they say, They always come back. I'mmm baaack. [Linked Image]
Hope to help more in the future.

[This message has been edited by tkb (edited 09-08-2005).]
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A typical LB can not hold the same number of conductors as the raceway it is connect to.

Wouldn't it be nice if the manufactures and the NEC would get on the same page with this?
I think that all LB's should allow the same fill as the conduits that connect to them. If this means redesign of the LB's then so be it.
The EMT was 3/4" less than 10' long, one 90ยบ to panel. Single phase, 9 wires plus ground.

This time I got my magic ladder in place and looked at the inside of the Red Dot LB. Indeed there was a rather sharp edge such as you would get if you drilled a hole in a block of metal The back part of the hole seemed to be chamferred but the front wasn't. Perhaps a late shift effort or lack of quality control.

Anyway my caution is to warn you to carefully inspect -- finger test -- these types of fittings before you pull.
~Peter
I left the business about 7 years ago. The products back then were starting to get bad. There were metal boxes with very sharp edges. The screws were always cut improperly. The paint would chip off of some products. The backboards of some panels were warped and bent. It is the "American Dream!" Charge more money for poorer quality products.
Well, of course, according to the manufacturer, you're supposed to have a helper at each end to feed the wires while you pull, right? ;D
At A Code Update Class We Were told that A Condulette is only rated for 25% Fill, And I've seen the markings on LB's that State the maximum wire size and Quantity being far less than 40%, But I've Never Seen it in the NEC. Is it NEC or UL?
Same thing with Exp proof Seals. If you order a seal Rated for 40% fill they send you the next trade size larger and 2 reducing bushings.
This probably wont change for a long time, As the Code making panel is busy with alot more serious issues. A wire shorting in a LB is unlikely to cause injury or damage to a structure.
allclear,
Look at 314.28 and 314.28(A)(3).
Don
Does the last sentence of 314.16(C)(1) pertain only to the conductors described in the first sentence? (#6 or smaller)
I'm with Mike on this one. Experience helps a lot in these situations. I use a lot of lube on tough pulls. I recently pulled six 12 ga. stranded wires through four 90 degree bends in 30 feet of 1/2" emt. It needed a lot of lube & wasn't near 40% fill. In my experience it can be very difficult to pull the maximum allowed number of conductors.

When I'm pulling I sometimes feel it scraping the outer layer of insulation. It's a good time to stop and correct the situation. I don't really understand the part about ignoring that scraping to the extent that you're damaging the outer and inner layers of insulation to get to the bare copper.

It probably has a lot to do with the fact that the cost of the wire came out of my pocket & if I damage it I'll pay for it again.

Dave
I saw something lately that said the clear coating on THHN was not necessary to maintain the integrity of the insulation. You can skin that.
Get yourself a set of "pull buddies". They work great. Here's the link: http://www.rack-a-tiers.com/pro_pull_buddy.htm#pull_buddy
The info about the outer covering on THHN came right from a cable manufacturer.

The outer jacket on THHN is stripped off before UL testing for dielectric strength, the coating is on the wire to provide gasoline and oil resistance. If there is no chance of oil or gasoline contact the jacket is unneeded.

I tried to find the thread but I had no luck.

Bob
Bob:

I think this is the thread you're looking for:
https://www.electrical-contractor.net/ubb/Forum1/HTML/006259.html
That was it, thanks. [Linked Image]

Bob

[This message has been edited by iwire (edited 09-17-2005).]
310.11 Marking in the 2002 code says
____________________________________________
(A) Required information.
All Conductors and cables shall be marked to indicate the following information.....
(1) The Maximum rated Voltage
(2) The proper type Letter or Letters for the type of wire or cable as specified elseware in this Code
(3) The manufacturers name, trademark, or other distinctive marking by which the organization responsible for the product can be readily identified.
(4) The AWG size or Circular Mil area
(5) Cable Assemblies where the Neutral conductor is smaller than the Ungrounded conductors shall be so marked

(B) Method of Marking
(1) Surface Marking The following conductors and cables shall be durably marked on the surface. The AWG size or circular mill area shall be repeated at intervals not exceeding 24" .......
(1) Single- and Multiconductor rubber- and thermoplastic- insulated wire and cable
(2) .......
____________________________________________

I've pulled 500 mcm THHN off of reels in sub-zero temperatures and had had the outer jacket blow off the conductors, the entire length. I thought it was wrong and said something about it, But it still wound up getting installed. Don't crucify me for doing it because it ended up in an underground mine. but we try to do things down there just like we do things on any other job or better. On a seperate occasion i've seen all of the insulation blow off of wire pulling it off the reel during cold weather. It was impressive to see and hear! A loud bang and then Bare copper. Ended up calling the manufacturer and they said THHN/THWN is not supposed to be installed While the temperature is below 20 F

Justin
"Ended up calling the manufacturer and they said THHN/THWN is not supposed to be installed While the temperature is below 20 F"

And when you said, "Since we can't control the weather, what type of cable insulation are we supposed to install?", what was the reply?
Allclear,
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Don't crucify me for doing it because it ended up in an underground mine. but we try to do things down there just like we do things on any other job or better.
Justin,
Don't think for a second that you would be crucified here, for posting that.
My God, if that is what it takes, we'd all be leaving here!. [Linked Image]
Justin welcome to ECN.

I take it your reference to 310.11 was about losing the required marking if the outer plastic comes off? [Linked Image]

That got me to thinking about it so I went down to the basement and stripped some 12 AWG THHN of the plastic sheath.

One roll the labeling came of with the plastic, the other roll the labeling was on the inner layer and stayed in place.

I guess it depends on who makes the wire.

Bob
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