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New Small Metal Garage Disconnect

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SuperStructure

Member
Joined
Feb 15, 2025
Messages
18
Location
NE, IL, & East TN
Greetings,
I am having an 18 x 20' steel garage delivered in 3 weeks.
Simple power run from a 40A breaker in main house panel.
Underground 28" trench with 8/3 UF-B cable.
I will be using this 125A box inside:
40A main breaker.
12/2 MC cable feeding 4x LED lights (15A breaker) and 4x GFI outlets (20A breaker).

Simple right...

My electrician said I need a separate electric disconnect for a detached building.
Not a big deal... So, I looked at the following disconnect with 2 'WR' outlets(handy addition) to be put right outside the building entry point:

$50 my cost.

My Electrician told me I should not use this GE disconnect. He has a SqD box that would be better without WR plugs:

$200 my cost.

Any Opinions??

Thanks
 
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brewchief

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Messages
2,370
Location
Michigan
The one with the receptacle requires a separate circuit to power the receptacle, they are useful for when wiring an A/C unit that you need a service plug but don't have much space to mount a separate box, great for rooftop units.
 
M

mm08822

Well-known member
Joined
Jan 13, 2012
Messages
6,022
Location
NJ
SuperStructure said:
Greetings,
I am having an 18 x 20' steel garage delivered in 3 weeks.
Simple power run from a 40A breaker in main house panel.
Underground 28" trench with 8/3 UF-B cable.
I will be using this 125A box inside:
40A main breaker.
12/2 MC cable feeding 4x LED lights (15A breaker) and 4x GFI outlets (20A breaker).

Simple right...

My electrician said I need a separate electric disconnect for a detached building.
Not a big deal... So, I looked at the following disconnect with 2 'WR' outlets(handy addition) to be put right outside the building entry point:

$50 my cost.

My Electrician told me I should not use this GE disconnect. He has a SqD box that would be better without WR plugs:

$200 my cost.

Any Opinions??

Thanks
Click to expand...
I would use the Sq D disconnect but get a non-fused version. Plenty of room and proven hardware.

The ac disconnect is small and really a PIA. I'm not a fan of those combo units.

Definitely go bigger on the panel....20-24 space. You'll never regret that.
 
OP
S

SuperStructure

Member
Joined
Feb 15, 2025
Messages
18
Location
NE, IL, & East TN
brewchief said:
The one with the receptacle requires a separate circuit to power the receptacle, they are useful for when wiring an A/C unit that you need a service plug but don't have much space to mount a separate box, great for rooftop units.
Click to expand...

brewchief said:
The one with the receptacle requires a separate circuit to power the receptacle, they are useful for when wiring an A/C unit that you need a service plug but don't have much space to mount a separate box, great for rooftop units.
Click to expand...
OK thanks, just thought the external plug may be handy at some point, without having to add another outdoor box. Separate circuit is not an issue..

Would this simple pull-out be an option? I do not wish to complicate this and add unnecessary cost.

https://www.lowes.com/pd/Eaton-60A-NONFUSED-AC-Disconnect-Plastic/5005340133 OR


TIA
 
S

sparky 1971

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Joined
Oct 9, 2018
Messages
7,993
Location
Central Iowa
230.70 says that a disconnecting means is required for a separate structure, but unless there is a local amendment that I really doubt exists, an exterior disconnect is not required for a structure that isn't a house. (230.85). A main breaker panel would take care of the disconnecting means and it can be as large of a main as you need since you will have a 40 amp breaker at the house panel protecting the wire. This is the smallest panel I would go with and while it will cost a little more, the separate disconnect will not be necessary.


If you want an exterior disconnect, by all means go for it but get a real disconnect like the SQD in the link, those AC disco's are going to be more trouble than they are worth on top of mounting things to a metal garage are a PITA since there really isn't anything to screw to, something will have to be installed on the inside for backing or strut used on the outside to span the framing members.
 
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S

SuperStructure

Member
Joined
Feb 15, 2025
Messages
18
Location
NE, IL, & East TN
sparky 1971 said:
230.70 says that a disconnecting means is required for a separate structure, but unless there is a local amendment that I really doubt exists, an exterior disconnect is not required for a structure that isn't a house. (230.85). A main breaker panel would take care of the disconnecting means and it can be as large of a main as you need since you will have a 40 amp breaker at the house panel protecting the wire. This is the smallest panel I would go with and while it will cost a little more, the separate disconnect will not be necessary.


If you want an exterior disconnect, by all means go for it but get a real disconnect like the SQD in the link, those AC disco's are going to be more trouble than they are worth on top of mounting things to a metal garage are a PITA since there really isn't anything to screw to, something will have to be installed on the inside for backing or strut used on the outside to span the framing members.
Click to expand...
Perfect Sparky. The 'blanks' will dominate here, 4 breakers total. I am not worried about the 'look'. Simple and effective. Thanks
I shall check with 'local' codes first.
Cost is not much different either, as 'breakers' come with this value pack.
 
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SuperStructure

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Messages
18
Location
NE, IL, & East TN
wyliesdiesels said:
Forget the ext disconnect. Get a main breaker load center and be done with it. Dont forget to unbond the neutral, 2 ground bars, and 2 ground rods.
Click to expand...
Thanks Wylie,
I will use the 100A main load box per Sparky, and unbond the neutral.
Just spoke to the local inspector. Very nice guy. He said he is looking for "a" copper coated building ground rod, for any, powered, detached structure.

Do I need 2 neutrals and 2 ground bars for this 4-circuit application? I will send Mr. Inspector an e-mail with this Q to clarify.
Thanks Again All,
Dean
 
S

sparky 1971

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Oct 9, 2018
Messages
7,993
Location
Central Iowa
SuperStructure said:
Thanks Wylie,
I will use the 100A main load box per Sparky, and unbond the neutral.
Just spoke to the local inspector. Very nice guy. He said he is looking for "a" copper coated building ground rod, for any, powered, detached structure.

Do I need 2 neutrals and 2 ground bars for this 4-circuit application? I will send Mr. Inspector an e-mail with this Q to clarify.
Thanks Again All,
Dean
Click to expand...
Two hots, a neutral, and a ground from the house. One #6 bare wire from the garage to two ground rods 6' or more apart. Just pull the wire continuous through the first clamp and on to the second. You could run to the first rod and clamp it, then another conductor between the two, but you will need two clamps at the first rod. I'd put a ground bar (sold separately) on each side of the panel but with only four circuits, it's not a big deal if you only have one. The box the panel comes in will give you the part number for the appropriate ground bar(s), in the fine print I think it says accessories. You'll have a bar on each side from the factory and when you throw the green screw away, they will automatically both become neutral only bars.
 
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PCustoms

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Jul 23, 2011
Messages
23,280
Location
VT
Really should have kept the ground rod details here. I think you're getting bad advice in your other thread

New Garage footing - Grounding rod/rods inside footings?

Another question about new garage install. In-Footing Ground rod location? While I am pouring new footings, can I pound ground rods through my footing forms and attach my sub-panel grounds 10' apart in line with my buildings frame line? Concrete would be poured around the top of the rods. This...
www.garagejournal.com www.garagejournal.com
 
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S

SuperStructure

Member
Joined
Feb 15, 2025
Messages
18
Location
NE, IL, & East TN
PCustoms said:
Really should have kept the ground rod details here. I think you're getting bad advice in your other thread

New Garage footing - Grounding rod/rods inside footings?

Another question about new garage install. In-Footing Ground rod location? While I am pouring new footings, can I pound ground rods through my footing forms and attach my sub-panel grounds 10' apart in line with my buildings frame line? Concrete would be poured around the top of the rods. This...
www.garagejournal.com www.garagejournal.com
Click to expand...
Point taken PK.
Response was misplaced.
Just had a thought about ground rods inside footing and started new thread.
 
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