garage lighting question

[ricry]

I need to replace old and poorly done electrical in my detached garage. I plan to run a mwbc circuit to a double pole disconnect switch in the garage. I will put gfci outlets on one leg and lighting and door opener on the other leg.

As it stands now there is the 3 way switch in the garage that controls exterior lights on the house. The switch is on a different circuit than the garage. The 3 way wiring is in the same underground conduit as the old feeders to the garage and are spliced in the main panel inside the house.

Is doing the same with the new installation a code violation or otherwise bad practice?

 

[kwired]

I need to replace old and poorly done electrical in my detached garage. I plan to run a mwbc circuit to a double pole disconnect switch in the garage. I will put gfci outlets on one leg and lighting and door opener on the other leg.

As it stands now there is the 3 way switch in the garage that controls exterior lights on the house. The switch is on a different circuit than the garage. The 3 way wiring is in the same underground conduit as the old feeders to the garage and are spliced in the main panel inside the house.

Is doing the same with the new installation a code violation or otherwise bad practice?

225.30 comes into play here, assuming you are talking about a detached garage.

225.30 Number of Supplies.
A building or other structure that is served by a branch circuit or feeder on the load side of a service disconnecting means shall be supplied by only one feeder or branch circuit unless permitted in 225.30(A) through (E). For the purpose of this section, a multiwire branch circuit shall be considered a single circuit.


Where a branch circuit or feeder originates in these additional buildings or other structures, only one feeder or branch circuit shall be permitted to supply power back to the original building or structure, unless permitted in 225.30(A) through (E).

Take note of what that second paragraph says - the easiest way to comply with that is to supply the three way switched lighting circuit from a circuit already at the garage. Other option may be low voltage controls, wireless controls, or other signaling sent over existing lines.

 

[ricry]

thank you, that's what I was looking for.