ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
UL 508A SPACING
by ale348 - 03/29/24 01:09 AM
Increasing demand factors in residential
by tortuga - 03/28/24 05:57 PM
Portable generator question
by Steve Miller - 03/19/24 08:50 PM
Do we need grounding?
by NORCAL - 03/19/24 05:11 PM
240V only in a home and NEC?
by dsk - 03/19/24 06:33 AM
New in the Gallery:
This is a new one
This is a new one
by timmp, September 24
Few pics I found
Few pics I found
by timmp, August 15
Who's Online Now
1 members (ale348), 302 guests, and 14 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 3 1 2 3
#98852 06/17/06 10:01 PM
Joined: Aug 2005
Posts: 251
T
Member
A customer has a 10-2 circuit ran out to his shed.

Is there a legal way to turn this existing 10-2 circuit into a sub panel?

I thought awhile back I read a post where someone did something similar. And if I remember correctly the inspector failed it but it was legal by code.


Shake n Bake
Stay up to Code with the Latest NEC:


>> 2023 NEC & Related Reference & Exam Prep
2023 NEC & Related Reference & Study Guides

Pass Your Exam the FIRST TIME with the Latest NEC & Exam Prep

>> 2020 NEC & Related Reference & Study Guides
 

#98853 06/17/06 11:36 PM
Joined: Feb 2005
Posts: 693
L
Member
Well, yes and yes.

First would be to make it a 120v panel, jumping the hot to both lugs. Works fine as long as you don't need 240v. Wire as a sub-panel, with ground and neutral separated.

Second would be as a 240v. feed, using the bare as a combined neutral/EGC, as in the main panel, and the neutral/ground jumper used.

This requires no other conductive pathway (water pipe, coax-cable shield, etc.) between structures, as well as a driven ground at the shed.


Larry Fine
Fine Electric Co.
fineelectricco.com
#98854 06/18/06 01:27 AM
Joined: Jul 2004
Posts: 9,923
Likes: 32
G
Member
Better hurry on option 2. I understand that method is going to dissapear in 2008.


Greg Fretwell
#98855 06/18/06 11:22 AM
Joined: Jan 2005
Posts: 5,445
Likes: 2
Cat Servant
Member
Gfretwell, you are correct; the code comittee has accepted such a proposal. Comments are now being accepted.

Now, to be a little fussy about the idea....

Jumpering from one lug to another; well, make sure to replace the lug with one intended for two wires!

Now... 10-2 as a feeder. Doing load calcs at 3 watts / sq ft, you have plenty of capacity for almost any residential garage that is used as a garage.
There's the rub! In my cynical view of things, sub-panel = garage being converted to somethng else.
If they're planning to make a little apartment, they'll need 100 amps, not 30.
If they're planning to make it a workshop, you'll have to do further load calcs.


The advantages of another wire are immense. Indeed, I'd rather see 14-3 than 10-2!

Now.... how is the wire geting out to the garage? If this is a detached garage, romex is out, as it's not suitable for the application. UF is possible.
I am biased in favor of pipe. If I were doing this, I would run a vastly oversized pipe- at least 1" PVC. I'd also bury it DEEP- at least 2 ft. Call me paranoid. The larger pipe makes it easy to run larger wires later, and the cost increase is minimal.

Oh, and last (but not least)... you'll want a disconnect switch on the outside of a detached garage.

#98856 06/18/06 12:32 PM
Joined: Jan 2004
Posts: 1,507
G
Member
Reno- I question wether or not you'd need 100a. for an apartment. Based on the definition of an apartment found in Websters. As for the disconnect, it could be a 30a if the load did not exceed 2 circuits. If it were more than 2 circuits it would need to be probably 60a. See 225.39 Also should be SUSE rated. See 225.36. As for location it could be either inside or outside the building. See 225.32


George Little
#98857 06/18/06 02:54 PM
Joined: Feb 2005
Posts: 693
L
Member
Reno, a wire-nutted pair of pigtails would also suffice, no?


Larry Fine
Fine Electric Co.
fineelectricco.com
#98858 06/18/06 03:09 PM
Joined: Jan 2005
Posts: 5,445
Likes: 2
Cat Servant
Member
Larry, I am uncomfortable with the use of wire nuts on a feeder. I tend to think of 'feeders' along the same lines as 'services,' and would prefer not to have such a splice... even if it is technically 'legal.' Mabye I'd feel better about using NSI's.
Oh, and kudos for reminding us that a panel would mean a ground rod was required!

George, I seem to recall the code specifying a minimum 100 amp service to each "residence". That would mean 100 amps per apartment.

The main point of my earlier post was to underline the need to be clear as to exactly what the intended purpose of the sub-panel was. All too often, I've seen folks try to "finesse" things, and be unhappy with the result. Might as well do it right to begin with!

[This message has been edited by renosteinke (edited 06-18-2006).]

#98859 06/18/06 03:59 PM
Joined: Jan 2004
Posts: 1,507
G
Member
Reno- I'm having trouble accepting your statment

Quote
George, I seem to recall the code specifying a minimum 100 amp service to each "residence". That would mean 100 amps per apartment.

I don't see where you need a 100a disconnect for an apartment and I'm looking in the code and all I find is the need for 100a disconnect for a "One-Family Dwelling".

Apartments are a different type of dwelling and are part of a multifamily building.


George Little
#98860 06/18/06 05:10 PM
Joined: Jan 2005
Posts: 5,445
Likes: 2
Cat Servant
Member
We are talking about a separate structure, aren't we? I cannot see how, if converted into a residence, this would be anything but a "single family" residence, or more! I don't see how it could be called 'part' of the main residence.

Perhaps that distinction would hold, were we talking about converting an attached garage into a dwelling. But, in this case, the separation is a major factor.

I will admit that my first post, describing how I would like the job done, went beyond 'code minimums.' Some of this is preference; some of it is response to my not knowing just what the shed will be used for.

We have a practical sort of "catch 22" here. Almost any use of the shed, as a shed, can be quite nicely served by a single multi-wire circuit. Almost any other use, requiring a panel with multiple circuits, is going to need more than what 10-2 can deliver.

#98861 06/18/06 05:39 PM
Joined: Jan 2004
Posts: 1,507
G
Member
I guess I was hung up on your use of the word "apartment" and didn't want people assuming that apartments require 100a. feeders automaticly. The examples in the back of the book kinda show that. Interestingly enough if it is a single family dwelling supplied by a "Service" it must have minumum 100a Service Disconnect and 100a. Service conductors feeding it. After the Service disconnect if you were using fuses, you could use smaller fuses and conductors if they were adaquate to supply the load. 230.79

If the single family dwelling (not an apartment) is fed with a feeder instead of a Service the Disconnect must be 100a and the conductors feeding it only need to be large enough to supply the load and be potected at their ampacity. 225 39


George Little
Page 1 of 3 1 2 3

Link Copied to Clipboard
Powered by UBB.threads™ PHP Forum Software 7.7.5