So can I replace a 15single pole breaker with a 30amp single pole breaker with a 10gauge wire to an outlet even though im not going to use that much power? only for lighting building a grow room


6 Answers 6


Generally only 30A receptacles are allowed on 30A circuits, and 15 or 20A on 20A circuits, and 15A on 15A circuits.

210.23(B) Says a 30A branch circuit is permitted to supply fixed lighting units with heavy duty lamp holders in other than dwelling units...

So if the building occupancy in County records is residential you likely wouldn't be allowed to do that.

Alternately you install a $20 6 space electrical panel in the grow room and break your lighting circuits down to easier to handle 15A or 20A circuits and wire.

If in an allowed occupancy you are allowed to use cord and receptacle connections, but there are additional requirements in Article 422, including the receptacle is required to be directly above the light and stain relief issues.

  • Excellent answer that covers the code requirements and nuances related to answer the question, as well as a good alternate option.
    – Ack
    Apr 9, 2020 at 17:52
  • 1
    Additionally standard 15A receptacles such as a Lev CR15-w aren't (UL) listed for #10 wire. The instructions are part of approved use. leviton.com/en/docs/CR15_CR015.pdf Apr 10, 2020 at 13:51

You could but you would not be able to have any standard 15/20 outlets on this circuit. All outlets would have to be designed/rated for 30amp
If you did this and used 30 amp outlets, you would not have any overload protection at all for the lights, plugged or hare-wired.
Seems it would be better for you to run multiple circuits (15 or 20) to the grow room than to do all the work required to support the 30 amp circuit.
If your end goal is to install some device later that requires a 30amp circuit, then that a different issue.


If you already have the wire, yes, you can run it. You will still need a 20 amp breaker if installing the regular outlets. #10 AWG wire should fit in regular outlets but if you have difficulty doing it, you can pigtail it to some #12 AWG.


Yeah, you can't just use fatter wire and breaker if you want to power more stuff on a single circuit.

If the light had an internal problem, it would trip a 15A or 20A breaker, but not at 30A. And you go "oh, that sounds super random" not at all, the light is engineered to fail that way. That's part of the UL listing (assuming it has one lol).

If you are dealing with modern lights, check if they are 120/240V multi-voltage. If they are, then you can wire the circuit as 240V/20A using NEMA 6-15 receptacles. That will give you 4800 watts instead of the 3600W you'll get with 120V/30A.


In one word: NO, outlets must be protected by AT MOST 20A so if the breaker is the only protection to that outlet, it must be 20A or less.

Assuming the outlet is a regular 15A or 20A


So can I replace a 15single pole breaker with a 30amp single pole breaker with a 10gauge >wire to an outlet even though im not going to use that much power? only for lighting >building a grow room

The real question is Why do you need to upgrade to 30amps ? What are your plans ?

To me it sounds like you should be looking at a sub panel so you can divide up the circuits and if needed you can add more circuits at a later date.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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