When selecting an empty switch for an electric vehicle, the following steps can be followed:
1. Determine the motor power and battery voltage of the electric vehicle: Motor power and battery voltage are key factors determining the current demand of the electric vehicle. By using the formula P=UI, the approximate current demand of an electric vehicle can be calculated. For example, for a 1000W motor and a 72V battery, the current requirement is approximately 13.9A.
2. Choose the appropriate current capacity for the circuit breaker based on the current demand: After calculating the current demand, a circuit breaker current capacity slightly larger than this value should be selected to ensure that the circuit breaker will not be damaged due to excessive current during normal operation and peak load of the electric vehicle. It is usually recommended to choose a circuit breaker that is 10% \ \~20% larger than the calculated value, such as 15A \ \~17A in the above example. However, for safety reasons, larger circuit breakers such as 20A or higher may be chosen in practice. Note that for high-power motors, such as 2000W motors, their current requirements will be greater, so it is necessary to choose air switches with larger current capacity. For example, for a combination of a 2000W motor and a 72V battery, the current requirement is approximately 27.8A, and an air switch with a current capacity of 30A or higher can be selected.
3. Consider the current limit value of the controller: In addition to motor power and battery voltage, the current limit value of the controller is also an important factor to consider when selecting an air switch. The current limit value of the controller refers to the maximum current allowed to pass through the controller. To ensure the safe operation of electric vehicles, the current capacity of the selected circuit breaker should not be less than the current limit value of the controller. If the current limit value of the controller is large, such as 80A, a circuit breaker with a current capacity of at least 80A or higher should be selected.
When selecting an empty switch for an electric vehicle, the motor power and battery voltage of the vehicle should be determined to calculate the approximate current demand; Then select the appropriate air switch current capacity based on the current demand, and consider a certain safety margin; It is also necessary to consider the current limit value of the controller to ensure that the current capacity of the selected circuit breaker is not less than the current limit value of the controller. In the actual selection process, it is recommended to refer to the user manual of the electric vehicle or consult a professional for more accurate advice.