How Do I Select The Correct Fuse Rating?
A: When selecting a electric vehicle fuses fuse, both the rated voltage and rated current must be carefully considered to ensure safe and reliable operation.
(1) Selecting the Rated Voltage The rated voltage of a fuse is the maximum voltage at which it can safely interrupt a circuit.
①The fuse’s rated voltage must be equal to or higher than the circuit’s operating voltage.
②A fuse with a lower voltage rating than the circuit voltage must never be used.
Example:
①A 3A / 125V fuse cannot be used in a 250V circuit.
②A 3A / 250V fuse can be safely used in both 125V and 250V circuits.
(2)Selecting the Rated Current
The rated current of a fuse should be selected based on the circuit’s normal operating current and operating conditions.
Key factors to consider include: Normal operating current (Irm), Ambient temperature and derating factors, Inrush or surge current (I²t value), Expected number of current surges during product lifetime
A commonly used calculation method is:
In ≥ Irm / (Sc × Tc), Where: In = Rated current of the fuse
Irm = Maximum normal operating current of the circuit
Sc = Safety derating factor
0.75 (UL standard)
0.9 (IEC standard)
0.85 (JIS standard)
Tc = Temperature derating factor (refer to the fuse’s temperature derating curve)
The selected fuse rating should always be equal to or higher than the calculated value to ensure reliable operation and avoid nuisance blowing.
Summary:
①Choose a rated voltage ≥ circuit voltage
②Calculate rated current based on operating current, temperature, and safety factors
③Consider inrush current and application conditions
④Select the nearest higher standard fuse rating for reliable performance
What Applications Are Ev Fuses Typically Used In?
A: Applications of EV Fuses:
EV fuses are primarily used to protect the main and auxiliary circuits in high-voltage electrical systems of electric vehicles. Key application scenarios include:
1.Traction Battery Packs: Protect the main battery pack and sensing circuits from overcurrent and short circuits, preventing thermal runaway.
2.Traction Inverters: Ensure current safety in motor drive circuits, preventing overload damage to inverter modules.
3.DC/DC Converters: Safeguard high-to-low voltage conversion circuits, preventing damage from instantaneous high currents.
4.On-Board Chargers (OBC) and DC Fast Charging Modules: Protect current flow during charging and prevent overcurrent during the charging process.
5.Auxiliary Power Systems: Protect high-voltage circuits for components such as electric air conditioning compressors, PTC heaters, electric power steering (EPS), and seat or windshield defroster heaters.
What Is An Ev Fuse And How Does It Differ From A Standard Automotive Fuse?
A:EV Fuses: Overcurrent protection devices designed for 100–1000 V high-voltage, high-current circuits in electric vehicles, protecting key components such as traction batteries and inverters. They quickly interrupt faults to prevent fire and thermal runaway.
Difference from Standard Automotive Fuses: EV fuses are engineered for high-voltage, high-current applications, featuring arc-resistant and explosion-proof designs and resistance to harsh operating conditions. Standard automotive fuses are intended for 12 V/24 V low-voltage, low-current circuits and do not include specialized safety features.
High-Voltage System Role vs. Conventional Fuses: EV fuses serve as a safety barrier in high-voltage circuits, accurately interrupting fault currents and extinguishing arcs. Conventional fuses, when exposed to high voltage, can sustain arcs that may lead to fire and lack sufficient current-carrying capacity and environmental tolerance.
What Are The Typical Operating Temperature Ranges?
A: The operating temperature range of our EV fuses is -40°C to 125°C.
What Is The Interrupting Rating Of These Ev Fuses?
A: The interrupting ratings of our EV fuses are 20 kA, 30 kA, 33 kA, and 50 kA.
Can these fuses replace existing automotive fuse solutions?
A: Yes, our fuses can be cross-referenced with equivalent fuse models from leading manufacturers including Eaton, Bussmann, Mersen, Littelfuse, Edison, and SIBA. Compatibility should be verified based on electrical ratings and application requirements.
What voltage and current ratings are available for PROSEMI EV fuses?
A: Our Electric vehicle fuses are available in multiple industry-standard package sizes to support a wide range of circuit designs and power requirements.
Available package sizes include: 10x38mm, 14x40mm, 18x68mm, 10x28.5mm (max), 30x65mm, 38x70mm Voltage ratings include: 100 VDC, 200 VDC, 250 VDC, 420 VDC, 500 VDC, 750 VDC, 800 VDC, Up to 1000 VAC / DC
These options allow engineers to select the appropriate fuse based on system voltage, space constraints, and application requirements, ensuring safe and reliable overcurrent protection across a wide range of EV & HEV Power Battery designs.
Are Your Electric vehicle fuses Ul / Iec Certified?
A: Yes. Our Electric vehicle fuses comply with major international safety and environmental standards. They are UL certified and manufactured using lead-free materials, meeting RoHS compliance requirements.
These certifications ensure that our Electric vehicle fuses meet recognized safety, reliability, and environmental standards, making them suitable for use in a wide range of global EV Charging module and EV & HEV Power Battery applications.
Can I Request Samples Or Technical Support?
A: Yes. Samples and technical support are available upon request. Our engineering team can assist with product selection, application evaluation, and technical documentation to support your design and development needs.