New Industry Products

Littelfuse Claims Its New Fuses Are the First Automotive-grade 1000 VDC Offerings on the Market

March 22, 2022 by Gary Elinoff

The new fuses are aimed specifically at the harsh automotive environments of modern electric vehicles (EVs), where they have been designed to provide solid overcurrent protection.

In light of EV manufacturers’ move to an 800 VDC standard, Littelfuse on March 8 announced the release of its EV1K series of fuses, which it says constitute the first automotive-grade fuses rated at 1000 VDC.

“There is a clear need for more robust safety solutions as the eMobility market transitions from 500 VDC to 800 VDC pack voltages,” said Juergen Scheel, Littlefuse’s vice president of business development xEV/AEB.

 

The EVIK series. Image used courtesy of Littelfuse

 

To meet that need, Littelfuse’s EV1K series fuses are designed to withstand the stresses of severe automotive environments.  The fuses come with available amperages from 60 to 125 A, and additional fuses capable of handling currents up to 600 A are under development.

 

Series Specifications 

All members of the EV1K series can operate at 1000 VDC, with an interrupt rating of 30 kA. Additional specifications are listed in the table below: 

EV1K Fuse Specifications
Part Number  Amperage Rating (A) Nominal Cold Resistance (mΩ) Minimum Breaking Capacity (A) Melting (Pre-arcing) I2T (A2S)
EV1K060 60 1.826 300 850
EV1K070 70 1.877 350 890
EV1K080 80 1.395 400 1580
EV1K090 90 1.218 450 1910
EV1K100 100 1.053 500 2670
EV1K125 125 0.789 625 4500

 

Each fuse also has a very fast-acting opening (FF). 

 

Interrupting Rating

The amperage rating of a fuse represents the maximum current that it will allow to flow into a circuit under protection. The interrupt rating, or breaking capacity, is the maximum current that a fuse can safely handle in the instant before it breaks electrical contact. The EV1K series features an interrupt rating of 30,000 A.

This means that while individual series members can handle between 60 to 125 A continuously, a current surge of over 30,000 A will both break the flow of current and present a fire hazard.

 

Recommended Fuse Blocks 

For 60 to 125 A fuses, ratings that encompass the entire EV1K series, an LSCR001 fuse block is recommended.

 

LSCR001 and LSCR002 fuseholders. Image used courtesy of Littlefuse 

 

The larger LSCR002 is specified for fuses carrying 150 to 600 A. 

 

Applications

The EV1K provides over-current protection in high-voltage EV power supply applications. These include:

  • Energy storage and power conversion
  • High-voltage power distribution
  • On-board chargers (OBCs) 
  • Battery disconnect unit
  • Battery distribution units (BDUs) 
  • Traction motor inverters
  • DC/DC converters
  • Auxiliary loads 

 

Additional EV1K Series End Markets 

In addition to EV and hybrid passenger vehicles, members of the series will serve in on-board and off-board charging infrastructure. They will as well find application in heavy-duty electric and hybrid vehicles, trucks and commercial buses, and in agricultural and construction equipment. 

 

Physical Considerations

  • Measuring 25 x 73 mm, the fuses feature end caps incorporating integrated bolt-down terminals, to stand up against mechanical vibration and shock
  • Members of the EV1K series operate over a temperature range of 55 ˚C to 125 ˚C
  • The fuses are humidity-resistant 
  • The fuses have melamine bodies (UL 94 Flammability rating V-0) 
  • The units' terminals are of copper alloy (silver-plated) 

 

Environmental Notes

  • RoHS-compliant
  • Halogen-free
  • Entirely Pb-free 

 

Feature image used courtesy of Ford