New Series of its Thermally Protected Varistor Technology

Today, Littelfuse, Inc., a global manufacturer of leading technologies in circuit protection, power control and sensing, announced the LST Varistor series.

Constructed with a proprietary thermally protected varistor technology (TMOV) developed by Littelfuse, this new varistor incorporates both a built-in thermal disconnect function and an electric arc shield. This combination provides an 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 system

“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.
• The flexibility of using 50 kA and 75 kA Imax 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) 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.

Source: Littelfuse