Resettable Thermal Overload Protector For Electric Motors

Electric Motors’ thermal overload protection switches are electrical protection devices based on the thermal effect of current. They are primarily used to prevent equipment damage or fire risks caused by sustained overloads or abnormal temperatures. The following are key features:
I. Working Principle
‌Bimetallic Thermal Trip Mechanism‌
Two metal strips (active and passive) with different expansion coefficients bend under heat, triggering a mechanical mechanism to disconnect the circuit. The response time is typically in the order of seconds to minutes.
‌Combined Protection Design‌
Some models (such as the Schneider GV2-ME series) combine thermal and magnetic tripping to provide dual protection against overload (delayed) and short circuit (instantaneous).

Reset Thermal Overload Protection Switch 92 Series 8A 9 10A 12A 15A 20A Circuit Breaker

Thermal Overload Protector Push Button Manual Reset Circuit Breaker with 18AWG Wires and Cover

China Wholesale Thermal Overload Protector For Motors With Ul & Vde Certified Direct from Factory

Ii. Main Types
‌Reset Type‌: Manual/automatic reset, such as the Taiwan 98 series (3A-40A).
‌Electronic Type‌: A microprocessor monitors current, offering higher accuracy (such as the E99L model with indicator light). Thermal-Magnetic Type: Integrates a thermal element and electromagnetic coil, suitable for motor protection (such as the GV2ME20C, 0.1-32A).

Iii. Application Scenarios
Home Appliances: Klimatske naprave, garbage disposals, itd. (such as low-current circuit breakers, starting at ¥0.85).
Industrial Equipment: Three-phase motor protection (such as a 380V phase loss protector, ¥30.13).
Power Distribution Systems: Molded Case Circuit Breakers (such as the Schneider CVS400F, 320A-630A).

Manual Reset Thermal Switch Circuit Breaker Over Current Overload Protector (10A,15A, 30A)

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MRT0075 Manual Reset Thermal Overload, 3-4 HP, 4-Pole Auto Circuit Breaker

Iv. Selection Key Points
Nazivni tok: Must match load requirements. Na primer, 10A-16A is recommended for home use, while starting current should be considered for industrial motors.
Environmental Adaptability: For high-temperature environments, select a model with temperature compensation.
Certification Standards: Products that comply with UL, GB 4943.1, and other certifications are preferred.

V. Market Product Examples
‌Economical‌: Yueqing Lyuyi Electronics 98 Serija (¥2.85/unit).
‌Industrial‌: Schneider GV3 Series (starting at ¥20.90).
‌Intelligent‌: Chint NXR-25 Thermal Relay (7-10A, ¥34.20).