Thermal Protectors (UB8P & UB81P)

The UB8P and UB81P Self-Hold Thermal Cut-Out and Thermal Protectors are designed to provide overheat protection in high voltage applications. With a high 16 Amp capability, these models are well suited for thermal overload protection in a broad range of applications, including space heaters, dishwashers, mixers, blenders, grinders, and other electronic appliances.

The body of these surface mount devices is manufactured of phenolic resin and features a partition wall design that isolates the switch from the main body. This design effectively controls arcing that can cause a break in voltage contact (particularly in 250V applications), ensuring continuous operation to the setpoint.

The UB81P features a reinforced PBT enclosure for dust-proof applications; the UB8P has an exposed bi-metallic element for high accuracy and fast response to ambient air temperature. Both models incorporate a “self-hold” non-self resetting function that provides a high level of operational safety, especially in appliances with moving parts. The “self-hold” function ensures that after the element reaches its pre-set open temperature, the internal heater activates to maintain a self-regulating temperature, preventing the switch from resetting until the user disconnects the power.

The UB8P and UB81P models are manufactured with a built-in ceramic PTC (positive temperature coefficient) self-regulating heating element, which is positioned directly next to the bimetal-sensing switch. This design provides efficient insulation and fast thermal response time compared to units where the heater is mounted externally to the thermostat. Agency approvals include a UL rating of 16 Amps at 125V AC, 6,000 cycles resistive down to 125°C, and a European rating of 10 Amps (5A) at 250V AC, 6,000 cycles resistive (inductance) down to 125°C.