China Supplier of Motor Thermal Circuit Breakers

A thermal circuit breaker is a temperature-sensitive circuit protection device. It triggers circuit breaking by the deformation of a bimetallic strip, primarily used to protect equipment from damage caused by overload or abnormal temperatures.

Our thermal circuit breakers offer both thermal over-current trip-free and magnetic/hydraulic trip-free operation. Thermal Circuit breakers can be reset manually or automatically to resume normal operation. Thermal protection circuit breakers are temperature sensitive, single and double pole, fixed time delay, push-to-reset or switch function, and a compact design. Magnetic and hydraulic operation circuit breaker relays are not temperature sensitive. We offer single-pole or multi-pole circuit breakers, including 2-pole, 3-pole, and 4-pole versions. Our portfolio includes circuit breakers with various time delays and switch functions. These are side-by-side stackable. Our circuit breakers are designed for use in various applications, including industrial controls, aviation and marine systems, HVAC systems, pool/spa controls, lighting, test and measurement equipment, commercial appliances, medical devices, and surge protection.

Micro Thermal Circuit Breaker 28VDC, 250Vacar, 8Una, for threadneck panel mounting

Circuit Breaker Thermal Overload Protector, Manual Reset Overload Switch Black UL CE

Thermal Circuit Breakers with Rocker and Push

The following are its key features:
I. Working Principle and Characteristics
‌Bimetallic Strip Structure‌
Composed of two metal strips with different thermal expansion coefficients, connected in series in the circuit. When the current overloads, the metal strips bend due to heat, mechanically triggering the contacts to separate and disconnect the circuit.

It features a manual reset function and is reusable, unlike disposable fuses.

‌Environmental Adaptability‌
The protection threshold automatically adjusts as the ambient temperature rises, resulting in faster tripping and lower trigger current at high temperatures. It has strong resistance to mechanical shock and vibration and has been tested to operate stably within the 5-15Hz frequency range.

Circuit Breakers – Chinese Supplier of Thermal and Magnetic-Hydraulic

Motor Thermal Circuit Breaker, Series Trip, 250 Vacar, 50 VDC, 1 Pole, 5 – 30 seconds Trip Time at 200%

Interruptor de circuit tèrmic, Series Trip, 250 Vacar, 32 VDC, 10Una, 1Pole

II. Technical Standards and Classifications
National Standard: Complies with GB 4943.1-2011/IEC 60950-1:2005, defined as a non-manually adjustable temperature-sensitive protective device.
Type Examples:
K-type thermal circuit breakers: Commonly used in industrial scenarios, such as the Schneider GV2 series motor protector, which supports a current range of 0.1A-32A.
Molded Case Circuit Breakers: Such as the Schneider CVS400F, suitable for high-current distribution protection from 320A to 630A.

III. Application Scenarios
Household Appliances: Overload protection for air conditioners and electric water heaters.
Industrial Equipment: Motor protection (such as the Schneider GV2ME series) and short-circuit protection for power distribution systems.
Medical Devices: Temperature anomaly protection in power management systems.

IV. Selection Recommendations
Current Matching: Select a circuit breaker based on the rated load current. Per exemple, for home use, a 1P+N circuit breaker (such as the Chint NB3 series) is recommended. For industrial motors, the thermal-magnetic GV2ME is recommended.
Environmental Factors: For high-temperature environments, pay attention to the circuit breaker’s temperature compensation performance.