Sub Panel Cable - Electrical - DIY Chatroom Home Improvement Forum
Advertisement


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Like Tree1Likes
  • 1 Post By georgemcq
Reply
 
Thread Tools Search this Thread
Display Modes
Old 07-18-2019, 08:38 PM   #1
Member
 
Join Date: Feb 2019
Posts: 35
Rewards Points: 60
Arrow

Sub Panel Cable


Hey guys! Getting a little confused on what cable to run. I plan on doing the rough electric myself (trenching, conduit, running the cable) and hiring someone to do the hookups.

I have a 200AMP panel in my basement. I want to run a 90 or 100 AMP sub panel in an outside shop.

There will be about 50 feet of wire indoor from the main panel leaving the house. Once we get to the outside, I will need about 100 Feet of buried cable (in conduit).

The sub panel will be mounted on the outside wall. So from the outside of the structure up to the sub panel will be like 5 feet or whatever.

Total length about 150 feet. I want to use one single cable from panel to panel. I do not want to convert from one cable to another for inside/outside.


Questions:

What type of cable can I use for this?
Is conduit needed inside my house to the electrical panel? If so what do I need?
Is 2in conduit sch 40 large enough to fit the cable that I need through it?

We are also putting an additional grounding point in the shops footer. The mason is running a 20 foot piece of rebar in the concrete that we will tie into.

Trying to look this up and i feel like people use the same terms for different cables and its really confusing.
JoeSims is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 07-19-2019, 06:12 AM   #2
A "Handy Husband"
 
rjniles's Avatar
 
Join Date: Feb 2007
Location: South Carolina Low Country
Posts: 11,215
Rewards Points: 900
Default

Re: Sub Panel Cable


Big mistake trying to use a single cable. Run SER cable from breaker box to a junction box near the underground portion. Run 4 individual conductors in conduit out to the sub. THWN or XHHW conductors.

Sent from my RCT6213W22 using Tapatalk
__________________
My electrical answers are based on 2017 NEC, you may have local amendments.

Location: Coastal South Carolina
rjniles is online now   Reply With Quote
Sponsored Links
Advertisement
 
Old 07-19-2019, 10:21 AM   #3
Maintenance / Locksmith
 
Join Date: Feb 2018
Location: Hockley, TX
Posts: 181
Rewards Points: 362
Default

Re: Sub Panel Cable


Use conduit the whole distance and use 4 THWN wires with no junction points except each end.
Gregsoldtruck79 likes this.
georgemcq is online now   Reply With Quote
Sponsored Links
Advertisement
 
Old 07-19-2019, 11:07 AM   #4
A "Handy Husband"
 
rjniles's Avatar
 
Join Date: Feb 2007
Location: South Carolina Low Country
Posts: 11,215
Rewards Points: 900
Default

Re: Sub Panel Cable


Quote:
Originally Posted by georgemcq View Post
Use conduit the whole distance and use 4 THWN wires with no junction points except each end.

The reason I suggest SER cable for the in-house portion is that running conduit in an existing finished house can be challenging. If you can run the conduit fine, then use the same wire (not cable) for the whole run. Remember you can only have 360 degrees of bends in a single run. if you need more break it up with a pull box.
__________________
My electrical answers are based on 2017 NEC, you may have local amendments.

Location: Coastal South Carolina
rjniles is online now   Reply With Quote
Old 07-19-2019, 11:29 AM   #5
Member
 
Join Date: Feb 2019
Posts: 35
Rewards Points: 60
Default

Re: Sub Panel Cable


Thanks guys! What type of conduit do I need inside and outside? Can it be the same?
Also what size conduit do I need?

What gauge of aluminum wire do I need? all #2? Or will the ground be #4?
JoeSims is offline   Reply With Quote
Old 07-19-2019, 01:18 PM   #6
Member
 
Join Date: Aug 2012
Location: Upstate of South Carolina
Posts: 460
Rewards Points: 759
Default

Re: Sub Panel Cable


Quote:
Originally Posted by JoeSims View Post
Hey guys! Getting a little confused on what cable to run. I plan on doing the rough electric myself (trenching, conduit, running the cable) and hiring someone to do the hookups.

I have a 200AMP panel in my basement. I want to run a 90 or 100 AMP sub panel in an outside shop.

There will be about 50 feet of wire indoor from the main panel leaving the house. Once we get to the outside, I will need about 100 Feet of buried cable (in conduit).

The sub panel will be mounted on the outside wall. So from the outside of the structure up to the sub panel will be like 5 feet or whatever.

Total length about 150 feet. I want to use one single cable from panel to panel. I do not want to convert from one cable to another for inside/outside.


Questions:

What type of cable can I use for this?
Is conduit needed inside my house to the electrical panel? If so what do I need?
Is 2in conduit sch 40 large enough to fit the cable that I need through it?

We are also putting an additional grounding point in the shops footer. The mason is running a 20 foot piece of rebar in the concrete that we will tie into.

Trying to look this up and i feel like people use the same terms for different cables and its really confusing.
I'm only asking a question here to learn more. Are you saying that your going to place a 20 foot long rebar into the concrete footer & tie into that as a ground. I assume the rebar is laying in the concrete horizontal & not driven down into the ground (earth). If the rebar is horizontal, of what value would it be as a ground? Copper clad ground rods are generally 8 foot long & must be driven vertical into the earth to be in code. I just pounded in a full 8 foot ground rod into rock hard clay soil. It actually went in without a problem with a short handle six pound sledge hammer.


The ground rod is a cheap item. I paid $about $11 for it a the big box store. Did you check on the code for the way you want to ground. As I said, I'm just trying to learn. I don't have a horse in this race. Thanks.
maddog1 is offline   Reply With Quote
Old 07-19-2019, 01:29 PM   #7
Member
 
Join Date: Feb 2019
Posts: 35
Rewards Points: 60
Default

Re: Sub Panel Cable


Quote:
Originally Posted by maddog1 View Post
I'm only asking a question here to learn more. Are you saying that your going to place a 20 foot long rebar into the concrete footer & tie into that as a ground. I assume the rebar is laying in the concrete horizontal & not driven down into the ground (earth). If the rebar is horizontal, of what value would it be as a ground? Copper clad ground rods are generally 8 foot long & must be driven vertical into the earth to be in code. I just pounded in a full 8 foot ground rod into rock hard clay soil. It actually went in without a problem with a short handle six pound sledge hammer.


The ground rod is a cheap item. I paid $about $11 for it a the big box store. Did you check on the code for the way you want to ground. As I said, I'm just trying to learn. I don't have a horse in this race. Thanks.
Yeah I found that interesting too. My Mason brought up the idea so I looked it up in the code book. Sure enough. I also asked an inspector and he said its a great way to ground. Check out the last Paragraph Below:


E3608.1.2 Concrete-encased electrode.
A concrete-encased electrode consisting of at least 20 feet (6096 mm) of either of the following shall be considered as a grounding electrode:

1.One or more bare or zinc galvanized or other electrically conductive coated steel reinforcing bars or rods not less than 1/2 inch (13 mm) in diameter, installed in one continuous 20-foot (6096 mm) length, or if in multiple pieces connected together by the usual steel tie wires, exothermic welding, welding, or other effective means to create a 20-foot (6096 mm) or greater length.

2.A bare copper conductor not smaller than 4 AWG.

Metallic components shall be encased by at least 2 inches (51 mm) of concrete and shall be located horizontally within that portion of a concrete foundation or footing that is in direct contact with the earth or within vertical foundations or structural components or members that are in direct contact with the earth.
JoeSims is offline   Reply With Quote
The Following User Says Thank You to JoeSims For This Useful Post:
maddog1 (07-20-2019)
Sponsored Links
Advertisement
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Top of Page | View New Posts