Sizing Electrical Cable

[rwork]

Wasn't sure just which forum to post this question in, but figured someone here may have some suggestions.
I need to run new electrical service out to my workshop, and am not sure what size/ type to go with. My shop is located about 175 foot from the house. I currently have overhead wires, but I don't have the height clearance for trucks to get to a building site, so I'm going buried. Some have suggested regular service cable in pvc conduit. I've even had someone tell me to use plastic water pipe.
Any suggestions?

 

[newbury]

How many amp and volts?

 

[nwngunner]

First off get direct burry cable, make sure that you burry it to about 3 feet. Then at 18 inches you place a caution tape so if any one digs they hit that tape they know they are near something. WIth direct burry cable you DONOT put it in conduit. It is made to use the temp of the ground to cool the cable. I am currently putting in 400 amp service, 200 for the house and 200 for my shop. 220volt single phase. I am running about the same distance, you should look for sweetbirar triplex. its alunium 4/0 - 4/0 - 2/0

4/0-4/0-2/0 Aluminum URD, Per Foot at Menards

 

[grsthegreat]

I would need to know Amps of the shop panel and/or the amperage you require at the shop. Wire size is all related to distance and amperage.

And DONT use water pipe. Use listed electrical conduit. Electrical fittings are shaped very differently than water pipe. And cost isnt much different. Use schedule 40 pipe underground and schedule 80 pipe where it leaves the ground.

I personally always use pipe and never do direct burial.. mainly cause im an electrician and ive had to repair LOTS of direct burial lines, but have NEVER had to repair a pipe installation except when a backhoe ripped thru a pipe. ... but those dont count.


Direct burial wire is called URD cable and cannot be placed in conduit (by code..but i see lots of people do it). When using pipe, i use XHHW wire..which is also way cheaper than direct burial.

 

[nwngunner]

I was going by what my state electrical inspector told me i had to do according to our laws. He would not accept anything other then urd

 

[grsthegreat]

I was going by what my state electrical inspector told me i had to do according to our laws. He would not accept anything other then urd

you mean they dont allow wire in pipes?????

 

[nwngunner]

Its what they told me, and he said he was being nice and not making me put in a trace wire. I might have gotten away with trailer house wire and putting it in pipe, it just wasnt any cheaper. I found 4/0 4/0 2/0 for 1.89' It was the double disconnect wth 200 amp 150 amp meter pedistal that was expensive.

 

[arlen4720]

I don't think there is much, if any, straight rated URD anymore. Everything I have seen in quite a few years is dual rated USE-2. You can install it in conduit, but being multi conductor it would be a pain to pull. If you want to put it in conduit just use XHHW like grsthegreat said.
Is this a feeder from the panel in the house?

 

[rwork]

I meant to take a look at the old panel in the shop this morning, but forgot. I did notice the other day, that the old overhead wires (3), looked awful small.
I have a couple welders, Lincoln 225, Miller 211. And a good bit of woodworking equipment. 3Hp 220v table saw, 5 hp 220v planer, and several other machines with 1 to 1 1/2 hp 110v motors (jointer, bandsaws, shaper, radial saws, etc). I'm not sure how to estimate my actual amperage needs.

 

[grsthegreat]

if there not to run at same time, you wont have as much of a draw as if some will be run concurrently. With the welders a min 50 amp will probably work, but i personally wouldn't run anything less than 100 amps if it were mine. that allows for say a larger air compressor to run with several other tools or welder.