Need help reviewing sup panel requirements for a new garage/shop

Not open for further replies.


New User
Garden City, MI
I have seen a lot of questions on sub panels for remote shops. I just wanted to put all my information and see if what I’m planning is correct.
First the building will be a metal building.
  • The building is about 45 feet from the house.
  • The plan is to run (3) #4 wires and (1) #6 for ground
  • 2 Grounding rods that will be placed at least 6 feet apart.
  • 60- or 70-amp breaker in the house to feed the sub-panel
  • Currently it looks like it will (4) 110v breakers and (3) 220v breakers
Now for the big question, I bought a square-d sub panel that is MLO 86428. However, after reading several posts, it seems that I need a disconnect in the garage. I think my choices are going to be.

  • Add a main breaker at about $100
  • Back feed a breaker with a hold down, about $50
  • Return the panel and buy one with a main breaker
  • Install a separate disconnect.
If I use a main breaker, I have heard it should be a higher amperage then the breaker in the house. The logic I read was that this would make sure the breaker in the house stays the breaker and the one in the garage at a higher amperage would not trip is this correct?
Not open for further replies.