Maxium conduit run between pull boxes, NEC Code

[roger]

sounds like a fun day

Yeah, they were and you slept good those nights too.:grin:

Roger

 

[don_resqcapt19]

we use helpers backs and a long rope its a little more safer than a puller that can rip arms off

In most cases that type of problem is caused by the use of an incorrect rope. Power tuggers require a "static" rope...one with little stretch. Many of the ropes that are used are dynamic and using them with power tuggers can be very dangerous.
Don

 

[LarryFine]

I have used tuggers, pick up trucks, diggers, line trucks, backhoes, trackhoes, and cranes to make pulls, what ever it takes.

Tim Allen would be proud!

"Arrgh, arrgh, arrghhh!"​

 

[roger]

Tim Allen would be proud!

"Arrgh, arrgh, arrghhh!"​

No Larry, Tim would be envious.

Roger

 

[LarryFine]

No Larry, Tim would be envious.

Tugger envy?

 

[roger]

Tugger envy?

Might this actually be you talking?

Roger

 

[LarryFine]

Might this actually be you talking?

Bob, are we crossing the line yet?

 

[roger]

Bob, are we crossing the line yet?

Larry, my question was, are you envious, do you wish you own a tugger or multiple tuggers, this is a common tool for electrical contractors, you should check them out. :roll:

Roger

 

[LarryFine]

Larry, my question was, are you envious, do you wish you own a tugger or multiple tuggers, this is a common tool for electrical contractors, you should check them out. :roll:

Of course.

Not really. I don't do that kind of pull often enough to buy my own. I rent when I need one.

 

[kenaslan]

Back in the 70's when I first started it was 200' however that limitation was removed some time ago.

Ken
ACADMEP Test Dummy

 

[weressl]

Could anyone tell me what is the maximum conduit run (length) between pull boxes per NEC code? And what page of the NEC code book its on? I have the 2002 version of the NEC code book.

There is and are practical limitations to the allowable length. One mentioned was the pulling force and the other one is the effectiveness of the conduit to carry the ground fault current if it is used for such purpose Each coupling and connection will represent an additional resistance on the ground path where it can becomes so great that the GF would not trip the CB. Obviously threaded couplings have a much lesser resistance than the EMT connectors. Repeated GF's would also "build up" this resistance.

Interestingly the UL testing of conduits involves resistance testing and the maximum allowable conduit run limitation is given by the seting, but it is not published and/or supplied by the conduit manufacturers as installation instructions. I have seen this data on manufaturers web-site before and I seem to recall of it being 1000+ feet. It is perhaps not supplied because in practical terms such lenghts are just non-existent.

See http://www.steelconduit.org/pdf/ConGuide.pdf for additional info.

 

[don_resqcapt19]

Laszlo,
If you run the GEMI software from the steelconduit.org site, it will show that the conduit is suitable as an EGC in longer lengths than a conductor sized per Table 250.122.
Don