BR-B2D series thermal overload relay / motor thermal protection switch is mainly designed for the electricity protection system of single-phase AC motor (50Hz, 220V) in case of some abnormal working conditions like overload or stalling. It features small volume and high sensitivity. Apart from applications in motor, the bimetal thermostat is also seen in battery, air conditioner motor, and automotive seat heating system, etc.

Differing from BR-A1D series thermal protector which adopts casings made from stainless steel, BR-B2D series employs insulated plastic enclosure. It stimulates a rapid change of the bimetal's condition which results to the separation of 2 contacts and thus cutting off the circuit, barely relying on the bimetal's temperature sensing and the current thermal effect.

Under normal condition, for a thermal switch, when the temperature rises to the max point, the 2 contacts will separate and the switch is open. On the contrary, when the temperature drops to the allowable range, the contacts touch and the switch is closed.

Thermal overload relay drawings

Main Features
1. The motor thermal protection switch adopts insulated plastic casing
2. The max capacity of contacts: AC250V/8A (6000 times of service); AC125V/12A (6000 times of service)
3. Opening temperature: 50-130℃, in increment of 5℃; tolerance of opening temperature: ±5℃
4. Standard wires: UL3266 #22, white, 70mm; wire length and length of stripping is customizable; single-strand copper wire whose diameter is 0.6 mm should be mounted in an inserted way
5. Contact resistance: 50 mΩ (under room temperature)

Open and Close Temperature:

Index
Induction Motor Thermal Switch, Thermal Protector
Motor Overheat Protector, Vehicle Motor Thermal Protector
Thermal Overload Protector