To ensure the electrical panel of your home works safely, a proper circuit breaker is essential. A circuit breaker is a specially designed device that protects the electric circuit by preventing over-current or excessive amounts of current passing through the panel.
Typically, a circuit breaker needs to have the proper amperes in its wiring to ensure it can hold the load. In homes, larger appliances like refrigerators, etc., need a 60-amp circuit breaker. Usually, you will find most 60 amp circuit breakers come with six gauge wire.
But is it correct? Well, it may not be ideal. A 4 gauge wire is ideal for a 60 amp circuit breaker, while a six gauge wire is ideal for 55 amp circuit breakers. However, many circuit breakers of 60-amperage come with 6-gauge wire. It is because many appliances may not even draw a supply of 60 amps even when working in full force.
What is Ampacity?
Ampacity or ampere capacity is the maximum current (amperes) carried by the conductor without exceeding its highest temperature rating. In other words, Ampacity refers to the maximum load of current carried continuously by a conductor or a device in a state when its steady-state temperature is fixed at a certain value.
It is calculated by dividing the wattage of a device by the rated voltage of its cables.
What is Gauge?
Gauge or American Wire Gauge (AWG) is a unit measuring the length, mostly used in the USA.
1 Gauge= 0.000254mm or 0.254 micron.
It is widely used in measuring the thickness or caliper of thin wires like electrical wires
What Size Wire For a 60 Amp Breaker?
For 60 amp circuit breakers, 4 AWG or 3 AWG wires are usually recommended. The Ampacity of 4 AWG copper wire is 85 amps at 75 degrees C. Hence, the four-gauge wire can carry a higher load at the same temperature. It also causes a higher voltage drop if you use a six-gauge wire. But most electrical appliances you use usually cannot reach 60 amps. It may reach 50 amps. So, a six-gauge wire can work fine.
But as per the NEC, for optimal results, the 80% breaker rating rule needs to be followed. In other words, the circuit breaker should handle 80% of the load of the rated or desired amperage. For example, a 60-amp circuit breaker should handle a 48-amp load ideally. If the load is more than this, you may need to go for a bigger wire size.
Factors to Consider When Choosing Wire Size for a 60-Amp breaker.
1. Wire Type
The amperage flowing through any wire is directly linked with the thickness of the wire. Electrical circuits with higher amperage ratings need to have thicker wires that can be near the load without generating excessive heat.
Thicker wires come with smaller resistance, while thinner wires have higher resistance at the same temperature. Higher resistance can cause a lot of problems, including overheating, melting, etc.
If you check from the table, the 60 amps wire needs a four gauge wire compared to the six gauge wire as it is thicker in size. The six-gauge wire is thinner and can overheat if the amperage is more than its permitted limit (60 amps).
| Wire Gauge | Amps |
| 2 Gauge | 95 |
| 3 Gauge | 85 |
| 4 Gauge | 70 |
| 6 Gauge | 55 |
| 8 Gauge | 40 |
| 10 Gauge | 30 |
| 12 Gauge | 20 |
| 14 Gauge | 15 |
2. Type of Load
The current load is extremely crucial when choosing the wire size for a 60-amp circuit breaker. In case the wire is too thin, overheating can cause the wire to melt, which in turn increases the risk of fire.
3. Voltage Drops
As per the NEC, the maximum Voltage drop in an electrical power distribution system is 5%. Voltage drop increases as the resistance increases, i.e., the length of the wire increases; frequent voltage drop can also lead to excess loss of energy and waste of electricity.
4. Length of Wire Run
The length of the cable is extremely important when choosing it. Cable length is directly related to Voltage Drop. If the wire is longer than the required length, it will have higher resistance. The wire can overheat, leading to electric fire and other mishaps. On the contrary, shorter lengths can result in voltage drop, which can result in excess power loss.
Common Types of Cables Used for a 60-Amp Breaker
1. Copper Cables
Copper is often used in electric appliances due to its good conduction properties. It is one of the most popular choices for wiring in electronic appliances and residential wiring. If the electrical wiring in the home is made of copper wire, the circuit breaker should use copper wire only.
2. Aluminum Cables
Aluminum cables are the second-best option for circuit breakers. If the fish house is built with aluminum wiring, the circuit breaker should come with an aluminum circuit breaker.
There are different types of aluminum wires which have markings depending on their size and type.
3. UF-B Cables
UF-B cables are usually used for outdoor circuit breakers. While it can be directly buried under the ground, it may not be buried in certain cases if the circuit demands special care.
4. MC Metal Clad Cables
Metal-clad cables or MC cables are widely used for feeders, branch circuits, power, lighting, control circuits, or even outdoors. It can be used concealed or exposed and can be directly buried in the ground, too. It is a type of assembled cable with one or multiple insulated circuit conductors. It can come with or even without optical fiber members enclosed with a corrugated sheath or interlocking metal tape. It is mostly used for branch circuits. It can only be used in indoor circuit breakers.
5. NM-B Non-Metallic Sheathed Romex Cables
Non-metallic sheathed cable is mostly used for residential wiring or appliances, electronic devices, and luminaries. According to NEC, the NM-B Ampacity limitation should be according to the 60-degree C conductor temperature rating. It is rated for 600 volts and can be used in both concealed and exposed conditions. It can be used for circuit breakers only for indoor conditions.
Applications of a 60 Amp Breaker
The 60 amp circuit breaker is usually used for larger electronic appliances like electric furnaces, industrial grade appliances, etc.
In the residential area, is it used for cooktops, large refrigerators, and other larger home appliances, or even in the main sub-panel of the home wiring.
Sometimes, it is used for sub-panels connected to different smaller circuits.
60 Amp Breaker – FAQs
Ans: It will not be suitable for handling a 60 amp load. The NEC recommends that the wire be suitable for 80% of the load of the rated amperage. Hence, a wire must handle 48 amperage to get a rating of 60-amperage. The 6-2 Romex wire has a maximum rating of 55 amperes and can only handle 44 amperages at maximum.
Ans: A larger wire size than the permitted level leads to higher resistance, leading to complications. So, using the permitted 4 AWG wire for 60 amps circuit is always ideal.
Ans: The insulation depends on the environment and the local electric cords where it is getting installed. If the wire is passing through the wall outdoors or in exposed areas, it needs insulation to prevent electric hazards or damage.
Ans: Extension cords are not ideal for this high-amperage circuit. Usually, extensions are made of 16 or 18-gauge cords. Hence, it could lead to overheating or melting of wire or even a short circuit.
Ans: Usually, a 60-amp circuit breaker can be used in a 100-amp panel if the panel has additional circuits and the total load remains within the limit.
Conclusion
For a 60-amp circuit breaker, 4 AWG wires made of copper, aluminum, or sometimes even UF-B cable or nonmetal cables can also be used. Even though some panels come with 6 AWG wires in a 60-imps circuit breaker, it is unsuitable. But, if the power load does not exceed 40 amps, a 6 AWG wire can be used.
