New varistors incorporate built-in thermal disconnect, electric arc shield

The LST Varistor series is constructed with a proprietary thermally protected varistor technology (TMOV) developed by Littelfuse. This new varistor incorporates both a built-in thermal disconnect function and electric arc shield. This combination provides additional robust protection to prevent catastrophic failure and fire hazard even under the extreme circumstances of abnormal overvoltage conditions or varistor end-of-life.

It is specifically designed for Type 1 and Type 2 Surge Protective Devices (SPDs) used in markets

and applications including:

Residential, Commercial, and Industrial buildings
Uninterruptable Power Supply (UPS)
Industrial motor control
Renewable energy
HVAC systems

“The LST Varistor provides several advantages when compared to other technologies on the market,” said Boris Golubovic, Vice President, Marketing and Strategy at Littelfuse. “By incorporating the LST in your latest design, you not only will benefit from its wide operating voltage range, high surge current rating, and compliment of options for microswitch, your SPD will also be more robust to meet the protection demands of your customer’s applications.”

The LST Varistor series offer these key benefits:

Facilitate meeting UL1449 listed Type 1 or Type 2 standards by incorporating 200 kA SCCR, 20 kA In, UL1449 Type 4 recognized component assembly.

Flexibility of using 50 kA and 75 kA I_max rated devices with the same footprint on PCB.

More options for designing remote indication/monitoring of SPD product or system via mechanically triggered ac and dc-rated microswitch (Normally Open/Normally Closed, pin length, 2 pin/3 pin/without pin).

Clear LST working status indication via a visual tab option that notifies service technicians and maintenance engineers to replace LST at end-of-life (EOL) in order to continue optimal surge protection for the end-product.

Wide Operating Voltage Range: Up to 690 Vac for 50 kA version, up to 550 Vac for 75 kA version.

The LST Varistor series is available in three trays containing 24 pieces each. Sample requests can be placed through authorized Littelfuse distributors worldwide.

Littelfuse, 8755 West Higgins Road, Chicago, IL 60631, Littelfuse.com.