ECN Forum Forums General Topics of the Trade General Discussion Area The sweet sound of insulation scraping off as you pull in wires

The EMT was 3/4" less than 10' long, one 90º 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