Electrical Service to Detached Garage

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johnfluevogs

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Location
NEW YORK STATE
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Engineer
I recently built a detached garage and am now deciding on how to bring service to the garage. NOTE: I am seeking opinions on different solutions proposed by different electrical contractors, and I am seeking to understand all the pros and cons.

The detached garage is 25 feet away from my existing attached garage where power will be taken from a main disconnect. The main disconnect is on the opposite side of the attached garage from where the underground conduit is placed between the two buildings. Therefore, the feeder will need to be run up and over the existing garage doors. In all from A to B the run is approximately 100' with at least five 90 degree bends.


Option A:
- install small single breaker box (100 A) tapped off the main disconnect
- run conduit the entire length (100 feet)
- install new 100 A sub-panel in new garage


Option B:
- replace 200 A main disconnect with a 200 A main load center (this would provide extra spaces/circuits in the existing structure for future)
- run conduit the entire length (100 feet)
- install new 100 A sub-panel in new garage


Option C:
- replace 200 A main disconnect with a 200 A main load center (this would provide extra spaces/circuits in the existing structure for future)
- Install new 100 A sub-panel #1 in the existing attached garage on the wall opposite from the main disconnect where the feeder will exist the building and enter the underground conduit (although a simple junction box would work, a sub-panel would provide additional circuit options for the future)
- Install new 100 A sub-panel #2 in the new detached garage fed from sub-panel #1 via the underground conduit


Thanks for reading and sharing!

***To be clear, I am not seeking advice or information about "how-to" wire/build the above.

If for some reason my request is in violation with the rules - then feel free to delete and feed me to the wolves!
 
For a start, all 3 of your solutions include
"- run conduit the entire length (100 feet)" (or 25 feet for option C)
"- install new 100 A sub-panel in new garage"

Looks like your decision is where you want to find your power. And how much re-work of the existing power you feel like doing. B & C will give you a nice, shiny, new main panel-- how old is the existing one? C will add a sub-panel good for the garage (although it's only across the room from the original).

Think about capacity for your future electro-car-- C will give you panels conveniently located for that 50-Amp circuit for a car charger...

Do you need conduit from the existing box to the other side of the garage? Whether you're going directly to the conduit or via a sub-panel?

How big is your dime??
 
Little Bill said:
Maybe some pics or drawings would help.
Click to expand...
I drew a picture first, but sadly couldn't figure out how to post :-( I will work on it...

PaulMmn said:
For a start, all 3 of your solutions include
"- run conduit the entire length (100 feet)" (or 25 feet for option C)
"- install new 100 A sub-panel in new garage"

Looks like your decision is where you want to find your power. And how much re-work of the existing power you feel like doing. B & C will give you a nice, shiny, new main panel-- how old is the existing one? C will add a sub-panel good for the garage (although it's only across the room from the original).

Think about capacity for your future electro-car-- C will give you panels conveniently located for that 50-Amp circuit for a car charger...

Do you need conduit from the existing box to the other side of the garage? Whether you're going directly to the conduit or via a sub-panel?

How big is your dime??
Click to expand...
Excellent feedback - Thank you! I agree, money may be a deciding factor; however, if I can plan for the future with only a marginal increase in price then I think it is worth it! I will admit, adding all the extra panels might be a touch "extra", but I've never heard anyone complain about having too many empty spaces in any panel 😁

The main disconnect is 30 years old and I felt replacing it with a panel would be nicer than merely tapping and installing a small "single" breaker box to feed the subs...
 
johnfluevogs said:
I drew a picture first, but sadly couldn't figure out how to post :-( I will work on it...
Click to expand...
Take a picture of your drawing with your phone. Then when you Scroll down to make a new post, you'll see an icon that you tap, and it will allow you to go into your gallery. Then you can insert your picture.Screenshot_20230628_120248_Chrome.jpg
 
James L said:
Take a picture of your drawing with your phone. Then when you Scroll down to make a new post, you'll see an icon that you tap, and it will allow you to go into your gallery. Then you can insert your picture.
Click to expand...
THANKS! For some reason I thought it required third party hosting.

Here are the diagrams:
Options.jpg
 
johnfluevogs said:
Unfortunately, the guy doing the work is not the one paying for it.
Click to expand...
The cheapest answer might be to install a junction box near the existing disconnect switch and tap in some hundred amp conductors to a fuse block in the junction box and then run UF from the junction box to the new building.
 
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