DaveC wrote:
Four AWG #1 conductors in 2-1/2 inch EMT. 50 ft of conduit, four 90 deg.
elbows.

Is this combination reasonable to pull with some lubricant? Or should I plan
some "pull boxes" in this run?

Thanks,
you shouldn't need lube and if it's that tight then
your not using large enough EMT.
also, you are allowed a total of 360 deg bends in the
pipe.
NE book states no more than 4 bends at 90 degree's
each.
if your going to use access elbows/pull elbows then you
surely don't need lube.


--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

Will all four be carrying current? Do not forget that the neutral is
considered a current carrying conductor, but a safety ground is not.
How much current on the circuit?

If all 4 are current carrying conductors, then the size of the conduit
needs to be overrated and/or the current in the circuit will have to be
significantly limited. If all four are intended as current carrying
conductors, then it will need to be derated by 80%. Since normal
derating of the conductors maximum current is 80% with only 3 current
carrying conductors, the actual current allowed will be around 65% of
the maximum for AWG #1 if all 4 are carrying current.

Just considering the size of conduit required for 4 AWG #1 wires is not
necessarily enough. The installation location, ambient temperature,
current on the circuit, insulation of the wire all play a factor into
figuring the proper installation parameters.

Even though I have all the information required to figure out what is
to local code, I typically have a licensed electrician double check
everything for safety.