First Class 12 Gauge Wire For 15 Amp Circuit

12 gauge wire is rated for a maximum of 20 amps.

12 gauge wire for 15 amp circuit. 15 amp dishwasher on 20 amp 12 gauge circuit. If the breaker is rated for 20 amps however you don t have a choice because the electrical code never permits you to use a 14 gauge wire on 20 amp circuit. We have a bathroom that we ran 20 amps to 12 gauge wire but we only have a few lights in there.

The lights definitely won t be using any more than one amp so i m wondering can i wire in a 15 amp switch for the lights. These ratings are for standard copper nm sheathed cable but there are instances where these amperage ratings vary. So any size circuit breaker of 20 amps or less will be ok.

The 14 gauge wire will also support a 15 amp circuit but this is the wire s upper limit and could increase the chance of overloading making the 12 gauge wire a safer choice for a 15 amp circuit. You can use a 12 gauge wire on a 15 amp circuit with room to spare. It is actually not uncommon to use a larger size wire than specified especially on long runs.

Refer to the chart below. We re finishing our basement and doing the electrical ourselves. The wire is 12.

Generally a larger wire supports higher loads and should be used when in doubt. For example there is aluminum wiring in some homes and aluminum wires have their own ampacity carrying. Recommendation because it s thinner and lighter 14 gauge wire is easier to run than 12 gauge.

If the circuit can perform adequately using 14 gauge wire then you spend money you did not need to but there are some situation where 12 wire is required. You must also use a 12 gauge wire when connecting an outlet rated for 20 amps as many gfci outlets are even if the appliances you plug in are rated for only 15 amps. Because it has even less chance of overheating 12 gauge wire is also acceptable on a 15 amp circuit.