What do you know about Molded case circuit breakers?

Molded case circuit breakers can automatically turn off the current after the current exceeds the trigger setting. Plastic housing refers to the use of plastic insulators as the outer housing of the device to insulate the conductors and the grounded metal parts.

• What are the design features of Molded case circuit breakers?

• What is the difference between a Molded case circuit breaker r and an open circuit breaker?

• What requirements are placed on the working environment around the Molded case circuit breaker?

What are the design features of Molded case circuit breakers?

Molded case circuit breaker r is designed to install contacts, arc extinguishing chamber, trigger and actuator in a plastic housing. As a rule, maintenance is not considered. It is suitable for the circuit breaker of the branch circuit. The overcurrent trigger has thermomagnetic properties. There are two types of thermomagnetic Molded case circuit breakers, the general thermomagnetic Molded case circuit breaker r, which is a non-selective circuit breaker with only two protection modes: overload long-term delay and short-circuit instant protection. Four protective functions time delay, non-delayed short circuit and ground circuit. Some new products of compact electronic circuit breakers also have a region selective locking function. Most Molded case circuit breakers are operated manually, some have motor drives.

What is the difference between a Molded case circuit breaker r and an open circuit breaker?

Molded case circuit breakers are also open circuit breakers. Common open circuit breakers include frame circuit breakers and Molded case circuit breakers. The former has a large capacity, the rated cut-off current is also large and the volume is large, so there is no plastic housing and all parts of the circuit breaker are mounted on a steel frame. The capacity of the latter is relatively small, and the rated cut-off current is also smaller, so the volume is small, and the entire circuit breaker is protected by a plastic housing. Generally, frame circuit breakers are used in high current power circuits, while Molded case circuit breakers are used in load circuits.

What requirements are placed on the working environment around the Molded case circuit breaker?

● Ambient temperature:

○ The upper limit of ambient air temperature is +40℃;

○ The lower limit of ambient air temperature is -5℃;

○ The average value of ambient air temperature for 24-hours does not exceed +35℃.

● Height: The height of the site should not exceed 2000m.

● Atmospheric conditions:

The relative humidity of the atmosphere does not exceed 50% if the ambient air temperature is +40 °C; it may have a higher relative humidity at a lower temperature; The monthly average maximum relative humidity of the wettest month is 90%, and the monthly average of the month is the lowest. Temperature +25°C, taking into account condensation on the product surface due to temperature changes.

● Degree of pollution: The degree of pollution is stage 3.

Zhejiang Shilong Electric Technology Co., Ltd. is located in Shahu Industrial Area, Yueqing City, Zhejiang Province, China. Our corporate culture is based on mutual trust, built on honest and transparent communication, uniform processes and fair collaboration.