DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Electrical (http://www.diychatroom.com/f18/)
-   -   200 amp service/500 foot run (http://www.diychatroom.com/f18/200-amp-service-500-foot-run-37089/)

retired2007 01-28-2009 08:59 PM

200 amp service/500 foot run
 
Please correct or verify my plan:

200 amp service entrance main with meter single phase 240 volt with 2 ground electrodes.


3-600 kcml copper thwn-2 1 neutral + two hots in 4" PVC conduit with steel sweeps over a 500 foot run.This is almost 3000 pounds of wire. Will pull boxes at 165 feet and 330 feet be adquate or is this too much weight to pull with lots of lube on a slight downgrade? Is this too much strain on the conductors and the pull sock? Is there a chart for max wire pull weight?

This run will go to another 200 amp panel treated as a main with its own 2 ground rods and that will feed 3 more 100 amp panels all at different buildings all treated as mains with their own ground rods. With this in mind, can I skip running the grounding conductor in the 500 fot run and also to each of the other 100 amp main panels?

Speedy Petey 01-28-2009 09:05 PM

WHY do you have to go 500' with secondary? Why can't you go with primary and put the transformer close to the house?

What made you decide to use 600mcm CU ?

How did you plan to terminate the 4" in a 200A panel?

retired2007 01-28-2009 09:56 PM

500 foot run
 
The utility co wants $22000 the run poles and wire the 500'

Is it worth it to put in and transformer? If so suggest one for me please.

The 600kcmil is from a volt drop calculator to keep the loss down. Actually the calulator indicate 750 but I derated figuring that the draw would almost never exceed 160 amps.

I planned to reduce the conduit size coming into the panel

Magnettica 01-29-2009 12:06 AM

PVC and steel sweeps? :eek:

Ever pull 600's before?

If you're pulling 3 of them 500' you better tie them to a bumper of a powerful truck and hope the rope doesn't break.

By the way, how will you even get the snake through the 300' portion of the run when they don't even make a 300' snake? Maybe they do make one but I've never seen one before.

This job may be beyond the scope of a DIY project.

InPhase277 01-29-2009 03:15 AM

Quote:

Originally Posted by Magnettica (Post 221154)
PVC and steel sweeps? :eek:

This is not too uncommon. Especially on long runs where the rope may burn through the PVC 90.

retired2007 01-29-2009 04:16 AM

retired2007
 
I was planning on pulling 160 feet each time with 2 pull boxes and using a forklift as a tugger with rope rated for 9000 pounds plus

Can anybody answer the transformer question? I would love to use smaller wire if I can overcome the volt drop over the 500 feet. The utility line volts are 118/235 and I would like to keep the drop to 3%. Is there a pad mount transformer I can put in at the end of the 500 feet to step the volts back up. The dollar savings using 2/0 thwn-2 0ver 600 kcmil might pay for a transformer and sure make the pull easier

Speedy Petey 01-29-2009 05:45 AM

Quote:

Originally Posted by retired2007 (Post 221186)
The dollar savings using 2/0 thwn-2 0ver 600 kcmil might pay for a transformer and sure make the pull easier

True on both counts.

$22k is insane for that distance. They just don't want to do it.
At the same time, what does 1500 feet of 600mcm copper cost???

Where are you located?
Is this a single family house?
Was a demand load calc done?
What are you basing the 3% on?
3% is a bit conservative, why not %5?

rgsgww 01-29-2009 07:25 AM

$22k sounds like they don't even want to go out there and look at it.
600mcm? You could go lower...I don't think you will notice problems with 5% voltage drop.

Why not aluminum?

wirenut1110 01-29-2009 09:08 AM

Any reason why you can't go with direct burial aluminum? You'll be looking at roughly $2,700.00 for the wire (where I am anyway). The drop for 500 mcm AL is 3.8% @160 amps and 4.7% at the full 200.

Speedy Petey 01-29-2009 02:41 PM

Quote:

Originally Posted by wirenut1110 (Post 221274)
The drop for 500 mcm AL is 3.8% @160 amps and 4.7% at the full 200.

This is key.

Either way, 600mcm CU is way too big.

wirenut1110 01-29-2009 03:06 PM

Quote:

Originally Posted by retired2007 (Post 221060)
This is almost 3000 pounds of wire.

A year ago you would have needed armed guards with that much.:eek:

Speedy Petey 01-29-2009 03:13 PM

Quote:

Originally Posted by wirenut1110 (Post 221494)
A year ago you would have needed armed guards with that much.:eek:

:laughing: :laughing:
No doubt!

rgsgww 01-29-2009 07:51 PM

If someone finds out that you have 600 mcm copper for your service...you may loose power in the night...

Cow 01-29-2009 09:43 PM

Quote:

Originally Posted by wirenut1110 (Post 221274)
Any reason why you can't go with direct burial aluminum? You'll be looking at roughly $2,700.00 for the wire (where I am anyway). The drop for 500 mcm AL is 3.8% @160 amps and 4.7% at the full 200.

My calcs don't match yours, I get 2.8% at 160 amps.

Personally, I'd probably pull in 2-500 USE AL, 1-350 USE AL, and a 1/0 USE AL grounding conductor. This is assuming 160 amp load and some line-line loads to allow a reduced neutral. If your area hasn't adopted the 08 code you may very well be allowed to omit the grounding conductor. Not exactly code legal, but I leave the sweeps off the ends sometimes when making long pulls with heavy wire. The aluminum wire will be much easier to handle than the copper would be, plus the reduced cost too.

No matter what you do, you should definitely run your plan by your local inspector. You can't afford mistakes on large projects like this.

micromind 01-29-2009 10:45 PM

This can certainly be done, even in one shot. I've pulled larger wire longer distances without problems.

A forklift and rope will work, you really only need the steel 90s on the end you pull from. The feed end doesn't matter. If you use a steel 90, you'll need to ground it, unless it's completely buried and inaccessable.

When using a forklift to pull wire from underground, the 90 at the pull end tends to come up out of the ground. Usually, it'll break the FA where it transitions from PVC. I've used a couple of solutions;

1) Bury a 10' piece of steel rigid conduit coupled to the 90. Park something heavy on the backfill on top of the steel conduit while you're pulling.

2) Pour a yard or so of concrete around the steel 90. Your pull won't be hard enough to lift that out of the ground, but a few or the pulls I've done......

Most pulling socks for wire this size are rated for at least 8000 lbs. Tie-wire the sock only at the back, not the front. This way, the harder you pull, the tighter it'll grip the wire. Figure that the part of the wire in the sock is unusable.

If you're using anything other than a rope specifically designed for pulling wire, it'll stretch considerably. If it breaks, or the sock comes loose, it'll come flying out of the conduit with enough force to....well, you get the idea. Stay out of its way!!

When feeding the wire, the rope will stretch, then a bunch of wire will be drawn into the conduit all at once. Make sure your hands are not drawn in with the wire!

For every pound of push on the feed end, it'll pull a hundred or so pounds easier on the pull end. Push the wire into the feed end, don't let it be pulled in. Make sure the feed end can communicate with the pull end. The feed end might need to stop the pull occasionally.

Aluminum pulls way easier than copper, but if the insulation is XHHW, you'll need to lube it real good in PVC.

If you plan this out, and have enough help, it'll go in just fine.

Rob


All times are GMT -5. The time now is 02:14 AM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved