Littelfuse introduces TCMOV and SMOV Series Thermally Protected Varistors with the micro-switch indicator to help manufacturers meet the requirements specified in UL1449 (3rd edition) for Type 1 or Type 2 Surge Protection Device (SPDs) applications. TCMOV and SMOV Series Thermally Protected Varistors are especially
well-suited for surge protection devices, AC panel protection modules,
power transfer switches, AC/DC power distribution systems, photovoltaic
systems, and cell phone base stations.
-TCMOV34S Series features 34mm2-format varistors that combine high maximum surge capability (50kA) with an integrated thermally active element and offer a short circuit current rating of 200kA. In the event of overheating due to abnormal overvoltage, the TCMOV34S Varistor safely disconnects itself from the circuit. A built-in micro-switch triggered by a mechanical slide indicates when a circuit is completely isolated from the primary circuit.
-SMOV25 and SMOV34 Series Varistors safely disconnect from the circuit in a sustained over-voltage, intermediate current condition as defined by UL1449 (3rd edition). The integrated thermal element is positioned close to the MOV body to allow for a quick thermal response. The varistors offer high peak surge current handling and energy absorption capabilities with an operating voltage range compatible with common AC line voltage (115VAC to 750VAC). A separate micro-switch indicates when the MOV has been disconnected from the circuit. This separate switch isolates the monitoring circuitry from the primary circuit to ensure indicator circuit safety and simplify the user's circuit design.