Looking for advise on setting up a sub panel

Reply

  #1  
Old 04-26-19, 07:47 PM
S
Member
Thread Starter
Join Date: Apr 2019
Posts: 3
Received 0 Votes on 0 Posts
Looking for advise on setting up a sub panel

I want to put a sub panel into a detached workshop that I have. I will need to run about 75ft of cable (about 50 buried outside). Off of the sub panel I want a 240v 20amp outlet and a 120v 20amp outlet.

In theory a 40 amp sub panel would work but I cant seem to find one with 3 or more slots for breakers (2 for the 240v and 1 one for the 120v).

of course I could put a 60amp sub panel and have lots of slots but then because of the distance I would need to run 4/3 cable? But the only 4/3 cable I can seem to find is industrial armored cable at like $20 a foot.

If anyone has some advised on how to achieve this without thousands of dollars in cable I would REALLY appreciate it.

Also I would only be doing the grunt work and I would have a real electrician inspect my work and make the final connection.

thanks for your time.
 
Sponsored Links
  #2  
Old 04-26-19, 08:04 PM
J
Member
Join Date: Sep 2002
Location: welland ontario
Posts: 7,321
Received 186 Votes on 165 Posts
You could put in a 60 amp sub panel and still feed it with a 40 amp breaker.
 
  #3  
Old 04-26-19, 09:01 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 56,394
Received 748 Votes on 703 Posts
The 60A panel just means its maximum. Like joed mentioned you don't need to feed it with 60A. Are you looking for underground cable or are you going to use PVC ? I'm a PVC man on any underground circuit over 20A.
 
  #4  
Old 04-27-19, 04:36 AM
S
Member
Thread Starter
Join Date: Apr 2019
Posts: 3
Received 0 Votes on 0 Posts
I have been thinking about whether or not to put a conduit. Other then reduced risk of physical damage is there a reason to use conduit? I live in southern Ontario so the ground does freeze if that makes a difference.
 
  #5  
Old 04-27-19, 07:05 AM
P
Member
Join Date: Feb 2016
Location: United States, Virginia
Posts: 1,318
Received 45 Votes on 38 Posts
Use 6/3 UF-b direct bury if you don't want to mess with conduit underground. It should cost less than $4 US by the foot. That will give you 50A.
 
  #6  
Old 04-27-19, 07:34 AM
Z
Forum Topic Moderator
Join Date: Sep 2005
Location: USA
Posts: 5,044
Received 78 Votes on 73 Posts
Other then reduced risk of physical damage is there a reason to use conduit?
Protection is one reason, another is if you upsize the conduit it a bit, it's easy to upgrade the feed in the future.

I had a single 20A circuit to my detached garage installed however many years ago. I was able to easily upgrade to a 30A @ 240v just by pulling new wire and adding a subpanel since the original installer used 3/4" conduit. No digging or anything. It was glorious!
 
  #7  
Old 04-27-19, 09:40 AM
S
Member
Thread Starter
Join Date: Apr 2019
Posts: 3
Received 0 Votes on 0 Posts
One more question for you guys that have been so helpful! Do I need to put a separate ground rod into the ground or can I have the sub panels ground attached to the main panels ground?
 
  #8  
Old 04-27-19, 09:51 AM
A
Member
Join Date: Mar 2010
Location: USA
Posts: 3,927
Received 51 Votes on 49 Posts
The subpanel (more exactly the first panel) in the detached garage needs its own ground rods. And also a ground wire with the two hots and neutral coming from the main house.

A #10 gauge ground wire goes with #6 or #8 gauge feed conductors in conduit also.
 
  #9  
Old 04-27-19, 09:51 AM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
The subpanel needs at least one ground rod. That provides your GEC (Ground Electrode Conductor) for limiting atmospheric charges,

can I have the sub panels ground attached to the main panels ground?
Different ground, different purpose. That is your EGC to clear faults to metal parts.

Both the GEC and EGC are needed.
 
  #10  
Old 04-27-19, 09:58 AM
J
Member
Join Date: Sep 2002
Location: welland ontario
Posts: 7,321
Received 186 Votes on 165 Posts
Not in Canada. You do not need ground rods. A connection to the main panel ground is all you need.
From the Ontario ESASAFE FAQ pages

Question
I have a small building in which I wish to have a sub service installed. The sub service will be fed from my house. Do I need to have separate ground rods or a plate installed at the sub service?
Answer
It depends. The Code provides two options;
First, the sub service shall be grounded by connection to a ground electrode; or
Second, the sub service shall be bonded back to the main service with a bonding conductor run with the feeder conductors.
Note that buildings housing livestock are required by the Code to use the second option.

Rule 10-208.

Ontario Electrical Safety Code 26th Edition/2015
 
  #11  
Old 04-29-19, 05:40 AM
I
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,944
Received 42 Votes on 40 Posts
If you have rocky soil conduit is a good idea because the rocks shift around during freeze/thaw cycles and can cut the cable. It also allows a burial depth of 18" instead of the 24" for UF cable.
 
Reply
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


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: