Electric Vehicle Fuse Solutions

What Are EV Fuses?

Electric Vehicle (EV) and Hybrid Electric Vehicle (HEV) fuses protect electrical circuits, electrical equipment and batteries in an electric vehicle from electrical faults such as overloads and short circuits. The electrical circuits in Electric vehicles utilise direct current (DC) voltage. EV fuses often feature 500Vdc or 1000Vdc ratings. Like regular fuses, the voltage rating of an EV fuse is the maximum voltage for which the fuse is designed to operate. It will still work correctly in voltages below the maximum voltage rating.

Difference Between EV Fuses and Standard DC Fuses

Electric vehicle fuses differ from common DC voltage fuses in several important ways;

1. EV fuses are built to be more robust to withstand vibration, g-forces, humidity, etc. by constructing the fuse body using melamine laminated glass fibre rather than using ceramic casings commonly used for regular fuses.

2. The elements inside EV fuses are designed to achieve the required opening speeds and in-rush current handling demands of electric vehicles. This includes coping with thermal stresses and continuous current fluctuations. Fuses are specifically selected to ensure reliability and suitable protection.

Fuse Applications for Electric Vehicles

Fuses are required to protect electrical circuits in all types of vehicles, regardless of whether they have petrol or electric engines. Components like lights, radio, electric windows, etc., can be protected using standard automotive fuses.

Electric vehicles also require special purpose fuses for the protection of high-capacity battery packs, electric motors, power conversion devices & battery charging equipment, etc. These EV fuses are specially designed to ensure safe and reliable operation of the electric vehicle. The following image illustrates the type of fuses used in the power distribution unit and auxiliary systems of the vehicle.
 

Fuse Applications for Electric Vehicle Charging Stations

Battery-operated electric vehicles require charging stations to recharge the batteries contained within the vehicle. These charging stations are also known as Electric Vehicle Supply Equipment (EVSE). EVSE devices require circuit protection devices to ensure that any potential overload or short circuit does not pose a risk to the vehicle, charging station or user. EV Charging Stations are generally categorized into 3 levels. The fusing requirements of each vary due to the voltage and current capabilities, as shown below.