LB and big wires

[PoorOwner]

using a PVC 3/4" LB, pulling 3x 6AWG and a 10AWG ground.

The wires will go into the LB easily, but what's the best way to make the turn inside the LB?

I am thinking let it all out of the LB first (4 feet of excess after the LB), then take wire 1 at a time and thread through the exit until there is a loop/bulge and then I will go to the other end of conduit and retract it back

In practice, the wire is alot stiffer than I expected especially when bunched together to turn, would like to know what is the best technique to use.

I can glue the exit piece of the LB now (about 3 feet) or can do it later if it is easier.

Thanks

 

[matt_i]

This is where slack (extra) can help. I've always left a big loop right there until one end is terminated, then work backwards from there.

Like you I do one wire at a time, the wire can take whatever your hands can do to it without worry, its the sharp edges of the PVC body where the insulation can get nicked or shaved. The THHN clear outer jacket is very tough but it can get little "skips" nicked into it if you forget.

Once I get it 90% of the way "tightened" I will go to the far/still-loose end and give each conductor a firm tug. This is usually enough to get the wires formed tightly around the inner radius of the bend, which is good if you ever intend to pull more (in a bigger conduit).

 

[PoorOwner]

Yeah, it is roughing up the clear plastic (like sandwich wrap) of the jacket.. is that ok?
But I think it is more due to having a ridge when the pipe is not there yet during a "bench test" with no conduits.

 

[alfredeneuman]

The clear plastic is Nylon and it doesn't matter if it's damaged a bit, as long as the insulation beneath it isn't.

 

[Bert_]

Where are the big wires the title claimed? #6 is easy, hehe. Big wires are like 350 or 500 MCM, the size of your thumb.



It can be helpful to have someone help. One person feeding the wire into the LB and the other pulling. Also there is a right way and a wrong way to feed wires thought the LB. The wires should enter through the side and exit the back. It's not always possible to do it that way but try to design with that in mind, it is much easier.

 

[PoorOwner]

The LB is near the end pointing up 30" into the panel,

the back of LB is horizontal straight conduit on the other end. (but a tough crawl to get to)

My thought is to pull the wire into the LB back end first then finish threading it upwards. I didn't think there is a right way or wrong way (good to know) but I didn't want to push the whole length of wire through the elbow if I don't need to. I did a bench test with 1 wire, threading it up the exit then pulling the slack from the end and it snapped back into the LB just fine.

 

[Bert_]

For that size wire you'll be fine. It's not that it's really the wrong way, but there is definitely a right way. It gets to be a bigger deal with bigger wires.

 

[m32825]

PoorOwner,

Thanks for asking all these questions. You're just ahead of me and by reading your threads I'm learning what I need to know just in time. Thanks also to those responding. Garage Journal is a great resource because of people like you!

-- Carl

 

[ard]

I'd be done by the time I got to the end of your post....

 

[dscheidt]

The clear plastic is Nylon and it doesn't matter if it's damaged a bit, as long as the insulation beneath it isn't.

The nylon is what gives THHN, THWN, and MTW (and anything else with nylon coated PVC) their oil resistance. If you need the oil resistance rating, the nylon needs to be intact. If you don't, it doesn't matter.

 

[mobiledynamics]

Poor Owner -


It HELPS alot literally with a help. One person is pulling on one end, the other is finessing the placement on the LB.

 

[PoorOwner]

Yeah it is done, I retracted it back pulling it back into the LB, my wife tried to get some of the wire to go the short end she said it didn't work, but it is all in the LB now.

 

[LifeLongWNYer]

It sounds as if my answer is too late, but "just in case", I recently was talking to a buddy who owns a "one-man-band" electrician/troubleshooting/etc. business a few miles west of here. He reached into a box in his truck and pulled out something and said "look what I found". It was a piece of steel, about 3/4" wide, 1/4" thick and about 15" long. Near one end was a round, hourglass shaped metal "post" attached to the wide side. About 3" from that, was an identical "post".

I don't remember what he called it, but it was designed to bend the larger gauges of wire so they go through a LB fitting. He claimed it is the most useful tool he ever bought.

If there is any interest, I'll email him and see what it is called, and where he got it.


.

 

[dscheidt]

The clear plastic is Nylon and it doesn't matter if it's damaged a bit, as long as the insulation beneath it isn't.

It sounds as if my answer is too late, but "just in case", I recently was talking to a buddy who owns a "one-man-band" electrician/troubleshooting/etc. business a few miles west of here. He reached into a box in his truck and pulled out something and said "look what I found". It was a piece of steel, about 3/4" wide, 1/4" thick and about 15" long. Near one end was a round, hourglass shaped metal "post" attached to the wide side. About 3" from that, was an identical "post".

I don't remember what he called it, but it was designed to bend the larger gauges of wire so they go through a LB fitting. He claimed it is the most useful tool he ever bought.

If there is any interest, I'll email him and see what it is called, and where he got it.


.

The best known tool like that is the 'bulldog bender'. Pretty spendy, you'd need to do lots of big wires ot make it worth while. There's. tool called the 'bends all' which is the posts, with a square drive hole for a ratchet or breaker bar. Might be worth it for someone doing a garage panel, it's quite a bit cheaper.

 

[Bert_]

Lots of companies out there make wire benders. I have a couple. Never used one for less than 3/0 copper, usually don't even need it for that. Usually gets used when dealing with 250 or 350 MCM or larger.

 

[LifeLongWNYer]

Okay, it sounds as if my buddy's bender is not "news" to you guys, but it was new to me. As I recall, he said it was expensive, but he does a lot of work in machine shops, where large wire is used, so he felt it worth while. What he had did not have the hole for a ratchet.


.

 

[rburke65]

This is why you spend the extra dollar and run the 2” pvc conduit, then ya don’t have these issues.

 

[Bert_]

This is why you spend the extra dollar and run the 2” pvc conduit, then ya don’t have these issues.

For a couple #6's

 

[3rdgendslmech]

I ran 3 #2AL conductors and a #4 for ground to my barn over the weekend using 1 1/2 PVC. Total run from panel to panel was about 115' 2 90 degree sweeps in the ground an LB where each end entered the house and barn plus another LB to bring the wire into the bottom of the main panel. Used a fish tape to put a line in the conduit, my buddy came by to help me pull the cables.....i lubed the lines and pushed while he pulled from the other end. Took about 10 minutes.

 

[PoorOwner]

I think the key is to upsize the conduit if you can.

In my case the 3/4 conduit was rated for 4x 6 AWG wire and mine is close with the exception of 10 AWG ground. When I had I taped the wires to the fish tape it was a little crowed to get through the conduit where any turns are present.
We got a little stuck in the 2 45 elbows together that made a big offset, risk breaking the wire off the tape.

But if I could have know and sized up to 1" or 1 1/4" would be much easier.