A new one-family dwelling has an attached garage. What branch circuit does the Code require for the 125-volt receptacle outlets in that garage?
- AAny existing 15- or 20-ampere general-purpose circuit that already serves the rooms next to the garage
Sharing a general-purpose circuit with adjacent rooms is exactly what this rule was written to stop. A compressor or a shop vacuum then trips a circuit feeding bedrooms.
- BA 20-ampere circuit that is shared with the required laundry receptacle outlet elsewhere in the dwelling
The laundry circuit has its own dedication rule and may not take on garage receptacles. Combining them violates both provisions at once.
- At least one 20-ampere circuit with no other outlets except readily accessible outdoor receptacles
- DAt least one 20-ampere circuit that is also permitted to supply all of the lighting outlets in the garage
Garage lighting is another outlet on the circuit. Putting lights on it means losing the light when a tool trips the breaker, which is the situation the dedication prevents.
Why C is correct
The rule creates a fourth dedicated circuit alongside the two small-appliance circuits and the laundry circuit. Its purpose is to keep the tool and vehicle loads in a garage off circuits that also feed living space. The only outlets allowed to share it are readily accessible outdoor receptacles, which is a deliberate allowance so one circuit can serve the garage and the exterior receptacles near it.
What this question is testing
The item tests recall of the dwelling dedicated-circuit list and the specific limit on what else that circuit may supply, which is the part candidates most often get wrong.
On the job
Panel schedules get drawn early and this circuit is the one most often left out on a residential job, because the garage receptacles look like ordinary general-purpose outlets. The rough-in inspector catches it, and the fix is a new home run through framing that is already insulated. Adding one dedicated 20-ampere circuit at layout costs a breaker and a cable. It also solves the real complaint that follows every garage: a shop tool killing the lights.
Memory technique
The garage gets its own twenty, and only the outdoor receptacles get to ride along.
Exam tip
Learn the dwelling dedicated circuits as a set: two small appliance, one laundry, one bathroom, one garage.
Where to look it up
Look in the branch circuits article, in the section on branch circuits required for specific occupancies, under dwelling units.