What Size Wire For A 60 Amp Circuit Breaker?
The optimal wire sizes for a 60 Amp circuit breaker are 4 AWG copper or 3 AWG aluminum. The ampacity of the 4 AWG copper wire is 85 amps at 75°C. The ampacity of the 3 AWG aluminum wire is 75 amps at 75°C.
Smaller wires are not recommended even though their ampacity may be around 60 Amps because the maximum loading capacity of the electrical circuit should not exceed 80%.
Instead, you might want to size up if the wire runs for over 100 feet to account for the voltage drop. Every 100 feet, there is approximately a 20% voltage drop. For runs over 100 feet, use 3 AWG aluminum and 2 AWG copper wire. Size up every 100 feet. In most cases, however, runs of wires for circuit breakers will not be extremely long. There are other reasons to size up: you might want to use a bigger size of cable in case the breaker powers multiple appliances and there is an enhanced current draw, the circuit powers heavy-duty appliances, or the circuit is located outdoors where it is more prone to damage.
What Are the Applications of 60 Amp Breakers?
60 Amp breakers are used for the large appliances in residential, commercial, and industrial settings. In house settings, these appliances are the largest ones in the house. These include:
- Subpanels
- Largest models of hot tubs or spas that require significant lighting
- Central air conditioning units
- Level 2 EV charging stations that offer fast charging
- Large workshops with power tools
- Large commercial and industrial appliances
- High-capacity electric ovens and electric ranges
- Electric water heaters
- Garages and workshops with multiple appliances in them
50 Amp Breaker vs. 60 Amp Breaker Applications
50 Amp breakers and 60 Amp breakers are used for applications that are quite similar. The actual electric load of the circuit is what determines which one should be used. One important thing is that 60 Amp breakers are less common in residential settings because of standardization concerns. 50-amp and 100-amp breakers are simply more common in homes.
In general, most stoves, spas, and heaters can be serviced by a standard 50 Amp breaker, but 60 Amp breakers are sometimes required for heavier loads.
Types of Cables Used for 60 Amp Breakers
60 Amp breakers use common residential and commercial building wire appropriate for circuit breakers. Some of your options are:
- THHN/THWN in both copper and aluminum. This is the most popular option for circuit breakers. The single-conductor wires that are often used in conduit systems for residential and commercial applications. XHHW aluminum and copper cables are used in a similar way.
- NM-B Non-Metallic Sheathed Romex® Cable has two or more insulated conductors and a bare copper ground wire, all wrapped in a non-metallic sheath. The cable is only suitable for indoor applications.
- UF-B cables for circuit breakers located outdoors, suitable for direct burial without the conduit. UF-B cables may not be appropriate for a specific circuit in case the circuit does not allow for direct burial, so the best option is to check local codes.
- MC metal-clad cables have multiple insulated conductors, including with a grounding conductor, in a protective metal sheath. The metal sheath provides mechanical protection and serves as the grounding path. The cable is suitable for indoors and outdoors installations. However, outdoor installations should be dry.
