# 2 Pole for a shed?



## CADPoint (Jul 5, 2007)

This is an installation that I witnessed and installed under the supervision of a master in the fine State of NC. It was 3/4” PVC out to a shed in 18” trench. Both ends had a two pole breaker, for two hots, a neutral and a ground. It was composed of individual single circuit conductors of #12 THHN.

Is this installation correct?


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## MechanicalDVR (Dec 29, 2007)

CADPoint said:


> This is an installation that I witnessed and installed under the supervision of a master in the fine State of NC. It was 3/4” PVC out to a shed in 18” trench. Both ends had a two pole breaker, for two hots, a neutral and a ground. It was composed of individual single circuit conductors of #12 THHN.
> 
> Is this installation correct?


How long was the run and was it powering a light and a receptacle circuit?


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## CADPoint (Jul 5, 2007)

Yes multiple (4) receptacles, no outside GFCI, and lights inside.


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## telsa (May 22, 2015)

Crazy to go to that effort with such tiny conductors.


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## MechanicalDVR (Dec 29, 2007)

CADPoint said:


> Yes multiple (4) receptacles, no outside GFCI, and lights inside.


It was common in the past to do something like that but for years now it was more like a small sub panel in the shed if it is a workshop or somewhere along that nature.


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## HackWork (Oct 2, 2009)

Be aware that while code allows you to run a 20A MWBC out to a shed like that without requiring a panel, if they choose to install a subpanel then they also have to install the appropriate grounding.

I had a friend who figured he would install a small $15 panel as the main disco for the shed instead of a 2-pole snap switch. He failed inspection because he didn't install the ground rods. They are required if you install a panel, even if the panel isn't necessary.


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## MechanicalDVR (Dec 29, 2007)

HackWork said:


> Be aware that while code allows you to run a 20A MWBC out to a shed like that without requiring a panel, if they choose to install a subpanel then they also have to install the appropriate grounding.
> 
> I had a friend who figured he would install a small $15 panel as the main disco for the shed instead of a 2-pole snap switch. He failed inspection because he didn't install the ground rods. They are required if you install a panel, even if the panel isn't necessary.


I've done jobs in the distant past with just one circuit for lights and an one outlet with a three way in the house to turn on the light in the shed / garage.


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## HackWork (Oct 2, 2009)

MechanicalDVR said:


> I've done jobs in the distant past with just one circuit for lights and an one outlet with a three way in the house to turn on the light in the shed / garage.


Yeah, having 1 circuit is fine, even a MWBC counts as one. In that instance you don't need a panel or grounding, just a snap switch for a disconnect.


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## drspec (Sep 29, 2012)

like Hax said, you either need a 2 pole snap switch, a non fuse disconnect, a fused disconnect, or even a breaker enclosure for the disconnect, but if you install a sub panel then you need to do the grounding 

And the breaker size in the shed doesnt have to match the breaker size feeding since its just a disconnect switch

A lot of work in your case but definitely code compliant

I would have probably just ran some 12/3 UF with a snap switch and have many times


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## MechanicalDVR (Dec 29, 2007)

HackWork said:


> Yeah, having 1 circuit is fine, even a MWBC counts as one. In that instance you don't need a panel or grounding, just a snap switch for a disconnect.



Exactly.

Not that I have done one like that in decades other than just one lighting circuit for exterior lighting fixtures.


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## CADPoint (Jul 5, 2007)

I'm so novice w/ residential work.


> like Hax said, you either need a 2 pole snap switch, a non fuse disconnect, a fused disconnect, or even a breaker enclosure for the disconnect, but if you install a sub panel then you need to do the grounding
> 
> And the breaker size in the shed doesnt have to match the breaker size feeding since its just a disconnect switch
> 
> A lot of work in your case but definitely code compliant.


As I recall there was a HVAC type breaker disconnect in shed and did have a ground rod. 
I've never grasped that aspect that a shared neutral only see's the unbalanced load of two circuits, but that's another thread.


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## splatz (May 23, 2015)

cadpoint said:


> i've never grasped that aspect that a shared neutral only see's the unbalanced load of two circuits, but that's another thread


This drawing clarifies it for me: 









At any point in time over the AC cycle, 
the direction of the current returning from L1 
is OPPOSITE 
the direction of the current returning from L2 

so they cancel. 

The most current that can be on N is when one line is at full load and the other is at zero. Any other situation and the neutral carries less than either line.


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## TGGT (Oct 28, 2012)

HackWork said:


> Be aware that while code allows you to run a 20A MWBC out to a shed like that without requiring a panel, if they choose to install a subpanel then they also have to install the appropriate grounding.
> 
> I had a friend who figured he would install a small $15 panel as the main disco for the shed instead of a 2-pole snap switch. He failed inspection because he didn't install the ground rods. They are required if you install a panel, even if the panel isn't necessary.


So a subpanel to a shed needs rods? Do you bond grounding to neutral bar in this case then?



Sent from my SM-G360T using Tapatalk


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## HackWork (Oct 2, 2009)

TGGT said:


> So a subpanel to a shed needs rods?


 Yup. 



> Do you bond grounding to neutral bar in this case then?


No, you run a 4 wire feed (separate neutral and EGC) and you keep them separated in the shed's panel.


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## splatz (May 23, 2015)

TGGT said:


> So a subpanel to a shed needs rods?


Yes.



> Do you bond grounding to neutral bar in this case then?


NO, dangerous parallel path.


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## Big John (May 23, 2010)

I'm too lazy to check, does the wording only require GES with a panelboard or would you get gigged for not having electrodes on a disco?


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## HackWork (Oct 2, 2009)

Big John said:


> I'm too lazy to check, does the wording only require GES with a panelboard or would you get gigged for not having electrodes on a disco?


Only a panel:



> 250.32 Buildings or Structures Supplied by a Feeder(s)
> or Branch Circuit(s).
> (A) Grounding Electrode. Building(s) or structure(s) supplied
> by feeder(s) or branch circuit(s) shall have a grounding
> ...


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## HackWork (Oct 2, 2009)

splatz said:


> Yes.
> 
> NO, dangerous parallel path.


I beat you to the punch and said the same thing, yet you are getting all the Likes.


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## splatz (May 23, 2015)

HackWork said:


> I beat you to the punch and said the same thing, yet you are getting all the Likes.


I said it in a haiku though.


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## TGGT (Oct 28, 2012)

splatz said:


> Yes.
> 
> NO, dangerous parallel path.


That's what I was already aware of, but the ground rods seems excessive to me. What's the point in theory? Lower resistance path to ground for a fault?

Sent from my SM-G360T using Tapatalk

Nevermind, I was being lazy because I was on my phone, I'm reading about it now.


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## Kaffeene (Feb 11, 2014)

Couple years ago I installed a 60A 6 cir. panel in my shed. I installed ground rod and grounding electrode to rebar in concrete slab.

I thought that would be plenty and I'll probably be alright, but I have 9 lighting loads (mostly LED though), mini fridge (for beer), several receptacles, 12A pool pump and now I'm adding a 240V 20A heat pump for the pool. 

I used all 6 spaces. 15A for lighting, 2-20A for receptacles, 20A for pool pump and DP20 for heat pump.


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## MechanicalDVR (Dec 29, 2007)

Kaffeene said:


> Couple years ago I installed a 60A 6 cir. panel in my shed. I installed ground rod and grounding electrode to rebar in concrete slab.
> 
> I thought that would be plenty and I'll probably be alright, but I have 9 lighting loads (mostly LED though), mini fridge (for beer), several receptacles, 12A pool pump and now I'm adding a 240V 20A heat pump for the pool.
> 
> I used all 6 spaces. 15A for lighting, 2-20A for receptacles, 20A for pool pump and DP20 for heat pump.


You need to upgrade and leave some spare spaces, better call an electrician!:jester:


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