How hard would it be to pull new 8 AWG conductors through 2" PVC conduit 3000'?

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Jarretuck6

Member
Location
Philadelphia
How hard is kind of subjective. Anything is possible. How many #8’s? How many 90’sAnd I imagine you have pull boxes in that 3000’ ft?


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Fulthrotl

~Autocorrect is My Worst Enema.~
How hard would it be to pull new 8 AWG conductors through 2" PVC conduit 3000'? The conduit is from 1999.
Any ideas or suggestions would be welcome.

let's put the best face on it.... 480v. 3ph.
#8 is good for 3 amps with the voltage drop.

set that aside. is there a pull string? is there a
conductor you can use as a pull string?

is it plastic, or steel?
underground, or overhead?
how many pull points?

your answer will vary from "wheeeeelllll....." to "nfw",
depending on your answers.
 

MrJLH

Senior Member
Location
CO
Very Hard,

If your conduit is that old, likely the conduit has shifted underground and it will be very difficult if not impossible to re-pull.
 

synchro

Senior Member
Location
Chicago, IL
Occupation
EE
Very Hard,

If your conduit is that old, likely the conduit has shifted underground and it will be very difficult if not impossible to re-pull.

And if conductors have to be pulled because old ones have failed, then the liklihood that conduits have shifted or been crushed, etc. is even higher.
If there are existing wires have you checked that they can be pulled even a little without breaking something?
 

kwired

Electron manager
Location
NE Nebraska
Visualize putting four 3000-foot rolls of #8 wire (~600 pounds) on a pallet and dragging it across the floor.
Exactly, at very least you will have to pull the weight of the conductors. Likely will be more friction within 3000 feet of pipe than the smaller surface area of that pallet with the reels on it.
 

tom baker

First Chief Moderator
Staff member
How Hard? very hard, just due to the weight of the conductors
Suggest digging up the conduit, about every 500 ft, put in 90s and a handhole, IE a 18x24x 12 deep concrete handhole with lid, long sweep 90s. I find handholes are easy to pull in and out as they are at grade.
Plus breaking up the conduit into 6 runs will help you if the new #8 doesn't pull you have narrowed it down to 500 ft.
Also - very important - use mule tape to pull with. Mule tape won't burn the 90s..., but first pull a rat or rag to clean out the conduit. A mandrel would be better.
 

MrJLH

Senior Member
Location
CO
I was just thinking of asking this, it's along the same lines: what is the longest pull y'all have done?

I just did a 3000' run with a 80ft elevation change. My electricians were not happy. Luckily there is this thing called hydrovac, but that is expensive. The Instrument engineer who came up with the idea said it was cheaper than doing a wireless radio system for some PLC control signals. I think there were 10 pull boxes.
 
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
EC - retired
I just did a 3000' run with a 80ft elevation change. My electricians were not happy. Luckily there is this thing called hydrovac, but that is expensive. The Instrument engineer who came up with the idea said it was cheaper than doing a wireless radio system for some PLC control signals. I think there were 10 pull boxes.

We just did some simple radio control because we did not want to trench 1400' and we would have pulled it straight through. Raise your rates a bit:D.
 

Cow

Senior Member
Location
Eastern Oregon
Occupation
Electrician
I was just thinking of asking this, it's along the same lines: what is the longest pull y'all have done?

1600' between pull points a long time ago for an irrigation pivot. Now it's all cablecon.

A few times a year we'll do 750-1200' footers with no pull points in the middle. Really no different than shorter pulls, you just stand at the tugger longer pulling it in.

We do a lot of ag work, is the reason for all the long pulls.

I just did a 3000' run with a 80ft elevation change. My electricians were not happy. Luckily there is this thing called hydrovac, but that is expensive. The Instrument engineer who came up with the idea said it was cheaper than doing a wireless radio system for some PLC control signals. I think there were 10 pull boxes.

We did one around 1/2-3/4 of a mile about 14 years ago for a similar reason as you mentioned. Wireless wouldn't work or was cost prohibitive(supposedly), so we pulled a multiconductor cable through a bunch of handhole boxes. I only remember it because it was one of the first jobs I was on as an apprentice. No splices allowed, so we had to pull the slack out at each handhole and then feed it back in. That was a ton of slack!!!! And just two of us! Haven't done anything like that since, fortunately!!!
 

kwired

Electron manager
Location
NE Nebraska
1600' between pull points a long time ago for an irrigation pivot. Now it's all cablecon.

A few times a year we'll do 750-1200' footers with no pull points in the middle. Really no different than shorter pulls, you just stand at the tugger longer pulling it in.

We do a lot of ag work, is the reason for all the long pulls.



We did one around 1/2-3/4 of a mile about 14 years ago for a similar reason as you mentioned. Wireless wouldn't work or was cost prohibitive(supposedly), so we pulled a multiconductor cable through a bunch of handhole boxes. I only remember it because it was one of the first jobs I was on as an apprentice. No splices allowed, so we had to pull the slack out at each handhole and then feed it back in. That was a ton of slack!!!! And just two of us! Haven't done anything like that since, fortunately!!!
Wireless can work great for controls, not so great for the power circuit.
 

synchro

Senior Member
Location
Chicago, IL
Occupation
EE
Wireless can work great for controls, not so great for the power circuit.

Yeah, but it didn't keep Tesla from trying: ;)

https://en.wikipedia.org/wiki/Tesla_Experimental_Station

Recently WiTricity and others have developed products for wireless power transfer but only for very short range and relatively low power.
But they basically use the same method that Tesla was using by transfering power between resonant circuits, but updated with modern electronics.
https://en.wikipedia.org/wiki/Resonant_inductive_coupling
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I have done wireless a number of times for distances as short as a few hundred feet and it was generally far less expensive than having to trench and pull comm wire under ground. Too bad you can't have wireless power. :)
 

Installer

Senior Member
Thank you all

Thank you all

. I didn't answer right way because I actually posted this question for another engineer I work with.
  • So I got in my car and went and took a drive to the area and it turns out there are manholes every 700 feet.
  • So that should help.
  • The engineer decided to use Step Up and Step Down transformers per my education on this site, so we are back to 12 AWG.

Thank you everyone. I've learned a lot on this Forums as I have stated several times.
Thanks,
Respectfully,
Installer
 
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