DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Electrical (http://www.diychatroom.com/f18/)
-   -   Sub Panel (http://www.diychatroom.com/f18/sub-panel-32979/)

SoxFan 12-01-2008 07:31 PM

Sub Panel
 
I have searched this and other forums and read about 20 questions and answers concerning sub panels. Parts of some of these apply to my configuration and some of those seem to contridict each other. I have concluded that each installation is different enough that I need to ask some questions about my specific project.

I have a main panel with 200A service. I recently removed the range, water heater, and shed. The range and water heater were replaced with gas and I am building a new workshop to replace the shed. This leaves me with unused double pole breakers (a single 40A and two 20A).

I'd like to run 6/3 with ground cable from a 60A double pole breaker to the sub panel. I'd like to install 6 circuits in the new sub panel, four at 20A single pole for outlets and two at 15A single pole for lights. The total wire length between the main and sub panels is just under 50ft. I have 3/4" PVC burried and inspected between the house and shop. The PVC is about 20ft. I'd like to avoid splicing the feed from the main panel to the sub panel. The wiring from the sub panel to the outlets will be 12/2 and to the lights will be 14/2.

From what I have read I have a few concerns. From what I have read I can not put 6/3 NM-B cable in underground PVC. It is not feasable to get PVC from the sub panel all the way back to the main panel because of the location of the main panel. I could get within 2 feet. This seems to leave me with no choice but to splice. I think I will have to run 6/3 cable from the main panel to a junction box and run PVC from the sub panel to the junction box with individual 6AWG wires (although the ground could be 8AWG).

So here are my basic questions?

Do I have to splice?

What cable and/or wire types should I use?

Can I run the required wire in 3/4" PVC?

Did I overlook anything?

joey b 12-01-2008 10:14 PM

AFAIK, you will be ok with the 3/4" conduit. you can use UF-b for the entire run and eliminate the splice. What is stopping you from that other 2 feet of conduit? If you have a complete run then you can run individual strands of THWN. In some instances the THWN can be in flex conduit, but I am not too well versed. I'll be watching this as I have similar plans myself. BTW, with THWN, you will be able to use a 70 AMP breaker vs the 60 amp.

J. V. 12-02-2008 11:16 AM

[quote=SoxFan;192459]
So here are my basic questions?

Do I have to splice?

What cable and/or wire types should I use?

Can I run the required wire in 3/4" PVC?
/quote]


You can splice if you want to transition from NM inside to whatever wire you will use outside underground. You will need a box.

UF for direct burial. THWN for use inside conduit.

You will never get a cable pulled into the conduit. You should use THWN single conductors. Four wires 2-hot, 1-neutral, 1-ground.

Since you cannot get the conduit all the way from panel to panel, run NM to a box on an outside wall. Run it in from the back. Then run the THWN in the conduit all the way to the sub panel. The box is where you make up the connections.


All times are GMT -5. The time now is 09:05 PM.