135

Upper Limit Temperature Protection

MICROTEMP

for upper limit temperature protection. Known as a thermal fuse, thermal link, or TCO, the

MICROTEMP

circuit when operating temperatures exceed the rated temperature of the cutoff.

MICROTEMP

•One-shot operation cuts off electrical power

•Current interrupt capacity up to 25 amps @ 250VAC

•Low resistance

•Compact size

Operating Principle of the MICROTEMP

The active trigger mechanism of the thermal cutoff is an exclusively formulated, electrically

nonconductive pellet. Under normal operating temperatures, the solid pellet holds spring-loaded

contacts closed.

When a predetermined temperature is reached, the pellet melts, allowing the compression spring

to relax. The trip spring then slides the contact away from the lead and the circuit is opened (see

figures 1 and 2).

After a MICROTEMP

replacement procedure must include correction of the fault condition before the product is

operated again.

MICROTEMP

INTRODUCTION