Recently bought a house with a suspicious electrical setup running to a detached garage. Garage is about 70 feet from the main panel. Feeding the garage is 10/3 Romex with no ground wire on a 30amp breaker. The romex is fed to the garage from the roof of the house overhead. Inside the junction box in the garage is a mess - 10 gauge pigtailed with 10,12 and 14 garage wire feeding several outlets, lights and switches (see second picture).

Would love some advice on whether or not this is a safe enough setup. We have no need for 30amp power so I’m wondering if I can just change the breaker from 30a to 20a.

Also, concerned that there is no ground wire and how to remedy without installing a sub panel.

Thank in advance for any advice!

[junction box in garage1

overhead feed to garage


  • 1
    Wait, is that weatherhead with the 3 separate wires the feeder to the garage? Are there actually 3 wires coming out of that weatherhead and is the metal pipe grounded? Nov 11, 2020 at 20:51
  • 1
    @harper Yes that is the feeder to the garage with three wires coming in and out. The metal pipe is not grounded. Steve- I do not need 240v in the garage so that is what I’m thinking. You’re right if I do keep the 14 gauge wire, I’d go with a 15a breaker. Thank you both
    – Robert
    Nov 11, 2020 at 21:11
  • First off: what is actually used for the overhead cable to the garage? Is that a prefab triplex, or...? Nov 12, 2020 at 1:33

1 Answer 1


First there are multiple code violations even if done in the 60’s when Romex or nmb did not have a ground.

Having 2 hot and a neutral was ok I believe until the 1999 code change. But the max breaker is 15 because of the 14 gauge wire. If the 14 gauge was removed a 20 amp breaker could be used but that was the max when built and still is today without a sub panel.

The switches and outlets for 120v are only listed for 20 amp circuits a 30 amp is a violation (even if a 15 amp receptacle or switch they can be used on a 20 amp circuit and be code compliant).

Could this be made safe? Yes, change the breaker to a 15 amp OR remove the 14 gauge wire and go to 20 amp. Install GFCI protection on both lines you have 2 120v 15 OR 20 amp circuits at that point and this would be safe and even code compliant.

What would it take to make it better? Meet today’s code? I would suggest a sub panel but then you would need A ground would have to be pulled from the service or on a point from that same panel to the garage. A ground electrode would need to be driven or other method of grounding electrode to the panel. Then you could leave the 30 amp breaker in the main, install a 20 amp breaker for the #12 and a 15 amp breaker for the #15. And that would pass (what you have should have been flagged on the home inspection for the reasons I mentioned).

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.