When it comes to types and size of breakers for electric vehicles, there are few things you need to know. Circuit breaker size used for EV charging depends upon various factors, the main factor is the current electric vehicle battery draw. Current is measured in amperes (A) thus charger must be selected at levels greater than or equal to this value.
For example, if we assume that the charger consumes 20A, it is necessary to calculate the breaker size of at least 20 amps. It is recommended that the breaker must always be designed for 25% more power than the charger’s output. This is necessary to avoid overloading the electrical system and causing a fire.
Size of Breakers
Size of circuit breakers determines the ampere range of EV charger and responsible driving hours.
For example, the symbol 20A breaker support 16A charger amperage and 19 km charging current in the load calculated driving range. 30A breaker supports 24A charger amperage provide a nominal drive load range of 29km is calculated.
Similarly, 40A breaker size supports 32A charger amperage and charge per hour estimated driving range of 40 km. 50A rated circuit breaker provides 40A charger amperage an estimated charge per hour with a range from 48 km. 60A breaker size supports 48A rated load current and the 58km estimated charging driving range per hour. 70A or 80A breaker size supports 50A charger amperage and 60 km of estimated driving range per hour of charging.
| Breaker size | Charger amperage | Driving range per hour of charging |
| 70A/80A | 50A | 60km |
| 60A | 48A | 58km |
| 50A | 40A | 48km |
| 40A | 32A | 40km |
| 30A | 24A | 29km |
| 20A | 16A | 19km |
Types of circuit breakers
For charging system of electric vehicles there are two types of circuit breakers available, Single-phase, and three-phase circuits. Only one breaker is used in single-phase circuit breakers while in the three-phase circuit breakers use 3 breakers.
In order to avoid tripping and overheating the circuit breakers are sized according to their competency of handling current. extension cord carries low current because of their low current carrying capacity as compared to outlets. If an EV is connected directly to an outlet, a 30-amp EV charger requires 20-amp breaker. However, if the EV is connected to extension cord a 30-amp EV charger would need 40-amp circuit breaker.
Basic knowledge about “what type of circuit breaker you need is important”. As a rule, it will be 110 volts / 15 amperes and 220 volts / 20 amperes, depending on the type of vehicle you have (or want). Amplifier circuit 15 can be treated usually two or three vehicles is not a pressing issue. However, if there or more than three in a row, the switch cannot be able to charge them all instead it would trip because it has not enough power to charge them all at once.
Using a 20-amp circuit, only one vehicle can get charged at once because of its higher speed than the maximum voltage. However, they are often more expensive than the circuit 15 amperes, so they can make more sense if the budget is the question!
The most common use of the charging station are 240-volts or 120-volts. Type of outlets used for charging greatly effect type of breakers required. The breakers used for 240-volts outlets is 100 amps while breakers used for 120-volts outlets is 30-amps.
The circuit breaker must be installed for the power source of the electric vehicle in the load circuit. The switch must be rated at least 40 amps and labelled as “electric vehicle charger» or «EV». If you are installing a new system, select a higher current than usual so you do not overload electric vehicle charging. To restore the safety of the electric vehicle, you need a power management system on your computer.
Installation of different size of breakers for home charging
Charging stations require a dedicated line separated from the other circuit breaker in the house to avoid overloading the electrical system and causing a fire. If they are not included in the package, you need to install the charging station with a particular circuit breaker.
For most chargers, you have the option of charging stations or exiting the installation program. The latter requires an electrician to install since they must be connected to the electrical system and through the wall without using an existing connection or plug.
You can set the output garage EVSE (electric vehicle), and your EV can be charged at home. Electric vehicle chargers typically require 30 amps but can use 40 amps or 50 amps of adapter cable.
Your EV energy usage rate will tell how much energy it requires. When the power rate of the EV is unknown the finding out size of circuit breakers and charger types must be challenging. Electric vehicles can use a 110-volt charging system, and new vehicles and trucks will use the 220-volt charger installed system.
The system voltage can be used depending on the presence of electric system in the house or garage. Most countries standard house current is 110 volts, but the electric vehicle charger can be required to provide 220 volts. Although you can connect port connector charging in the car, but you can use the current 110-volt.
What size of breaker is expected for a 30-amp car charger?
Usually 30-amp vehicle charger needs 30A breaker size. 30-amp car charger provides 30-amps of power which is not enough for charging EVs. In order to charge EV, you will be needed to switch to larger breaker size. When installing a new line of battery products, we recommend using a cable of at least 40 amps or 50 amps circuit breakers. These circuit breakers are beneficials in providing enough strength and support to EV charging.
From here, assume that you have a large degree of electric vehicles, you must look forward for future benefits. For example, if you have a system of 40 amperes and finally bought an electric vehicle of 50 amps need, you can interact with terminal connectors without placing new lines created.
First, you need to make sure what size of breakers are used for EVs, and number of amperes they can handle easily. For most vehicles it is the circuit breaker of 30-amps, which is great to use at home or at work. However, if you live in a region that often interrupts the power, it may be best to use a 50-amp circuit breaker.
Numbers of amps needed to charge electric vehicle battery depends on the EV battery size. The higher the voltage higher number of amps should be required to charge battery fully. For example, the battery’s pack of Tesla’s model S, have 85 kilowatts energy capacity and therefore requires approximately 7500 amperes to charge fully.
Suppose you are interested in a Tesla charger device. You have to consider the current value of the output power that your vehicle can handle. Typical house outlets have amperage of around 15-amps so if you are willing to charge Tesla, you want to use 30-amps breaker, you should plug it into an outlet that’s rated at 40 amps or greater.
The amount of electric power use to charge electric vehicle depends on the size and model of the vehicle. The most widely accepted electric vehicle include the following:
Tesla Model S: 85kw per hour battery power supply, it takes about 20 kilowatts (kW)
Nissan LEAF: 24 kW battery power, and it takes about 6 kW
Chevrolet Bolt EV: 60 kWh battery, about 15 kW
The amount of energy in electric vehicle load also depends on whether it is connected to the output of 240 or 120 electrical outlets. If you put the machine into a power outlet 240V, it takes more power than if you connect it into a 120V outlet. For example, if you plug your EV into 240V outlet and turn the heating port and AC port in your car both at same time. In that case, it will use more energy than if you run just the heating unit or air conditioning during the charging time, even though both cases involve usage of same type of charger (I.e., 30A or 50A).