DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Electrical (http://www.diychatroom.com/f18/)
-   -   yes, another sub-panel question!!! (http://www.diychatroom.com/f18/yes-another-sub-panel-question-14541/)

tomia 12-17-2007 04:49 PM

yes, another sub-panel question!!!
 
Hello all! what a great informative forum you have here!

This is all the background info on my situation:

I am running service to my pole building 100 Feet from my house.
I had planned on 100 amp service but after reading this forum,
I realize it may be overkill.
I think I will start with a 60 amp breaker in the main feeding the 100 amp box I have in the pole building. I have a 24 inch deep trench running from house to PB. I've got the trench dug but this being Minnesota, I got sneak attacked by Winter. I will have to wait until spring to get the inspector out to have a look and fill the trench in. I have pounded two different 5/8 grounding rods into the ground over 6 feet apart
I will be using sched. 80 from the buildings down to 24 inches below grade. using birect burial wire

1st question:
I have #1-1-1 aluminum in the trench rated for direct burial, what size ground? and I should'nt have a problem using this size wire with a 60 amp breaker feeding a 100 amp breaker, correct?

2nd
is it against the rules to do the work inside the building Ie. the wiring up to the box, so when I do get the power up in the spring it is all connected (as opposed to getting power out to the building then doing the basic wiring)

3rd
I am planing on having cable, data telephone and a natural gas line in the same trench with about 6 inches of dirt between the electrical wire and the rest (any problem with that?)

4th
after looking at all the subpanel questions, it might be nice to have all that info gathered in one place somehow ( I dont know how, It is just an observation)

Thanks for your time
Tom

If anyone has any advice I am missing, I am all ears (or since I am online, all eyes)

jogr 12-17-2007 05:15 PM

If you wait till spring you'll likely have to redig the trench. I'd go ahead and run the cables now, get it inspected (if required) and fill it in.

You can generally do all your rough in wiring in the PB before the power is out there. Talk to your inspector about how far you can go with it as he may well want to do a rough in inspection and you don't want to have to undo work.

Don't know what ground wire size or about putting other utilities in the same trench. Most inspectors are very helpful and will always give you the answer that will satisfy the inspector.

goose134 12-17-2007 07:38 PM

If you are running sched. 80 PVC, you don't need to run direct burial cable. You can run wire with a moisture rating. Most THHN is rated for THHW as well. Take a look before you commit. The insulation jacket will have the insulation type printed on it. Anything that ends in W is rated for moisture.

The phone will have to be run separately, but it sounds like you thought of that. Your ground size will be #10. You may want to upsize if you are going over 100 feet though. Good luck

Stubbie 12-17-2007 07:43 PM

1 Attachment(s)
Quote:

1st question:
I have #1-1-1 aluminum in the trench rated for direct burial, what size ground? and I should'nt have a problem using this size wire with a 60 amp breaker feeding a 100 amp breaker, correct?
There is no problem with the 100 amp breaker being after the 60 amps however you may have a problem. That is that #1 may be too large for the lugs of a 60 amp breaker. See attachment below...not all breakers are the same but you should check yours for the wire sizes it will accept. It will say on the breaker spec label located on the breaker itself

As for the ground size a 10 copper or 8 aluminum equipment ground for 60 amp circuit breaker anything above 60 up to 100 amps needs 8 copper or 6 aluminum....see this table for reference.....you have no voltage drop concerns at 100 feet.
http://www.jhlarson.com/ind_tables/g...ble_250122.htm

Quote:

2nd
is it against the rules to do the work inside the building Ie. the wiring up to the box, so when I do get the power up in the spring it is all connected (as opposed to getting power out to the building then doing the basic wiring)
You should be able to do this no problem

Quote:

3rd
I am planing on having cable, data telephone and a natural gas line in the same trench with about 6 inches of dirt between the electrical wire and the rest (any problem with that?)
Nope but you will need to get the local code for the separation distances. Usually they want gas installed last if your going to separate vertically and minimum 6 inch separation either vertical or horizontal. Water is about the only thing you cannot combine in the same trench. But you would want it a heck of a lot deeper than 2 feet anyway.

Click image to enlarge

HouseHelper 12-17-2007 08:03 PM

If you think you may go larger than 60A, and the #1 feeders will allow that, use at least a #6AL ground with the three #1 conductors.

Stubbie 12-17-2007 08:25 PM

House helper brings up a very good point you most likely want a 6 al or 8 copper ground so you will have the right size ground when you install a 100 amp breaker someday. If this was a conduit run you likely could pull in another ground but this is direct bury so by all means 6 al or 8 copper.

220/221 12-18-2007 05:18 PM

Quote:

I will be using sched. 80 from the buildings down to 24 inches below grade. using birect burial wire


ACKKK!!!


It's only a few extra bucks, spring for the 100' of conduit.


Somebody someday will thank you.


All times are GMT -5. The time now is 01:49 PM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved