When using various circuits; we often hear about low voltage circuit breakers. Generally when the voltage of our appliances falls below a certain value, the low voltage circuit breaker will quickly disconnect the appliance from the power source, which will help to protect your personal safety and ensure that the appliance works under normal conditions. After understanding the general function of low voltage circuit breakers, we will take you to understand various questions about low voltage circuit breakers.

What is a low voltage circuit breaker?

Low-voltage circuit breaker is a kind of protector used in all low-voltage circuits, it mainly realizes the protection of circuits through the change of shape of the bimetal plate or the change of magnetic force of the coil of the electromagnetic mechanism, when there is a fault in the circuit, these two main parts will be combined with the other components to quickly react to cut off the power supply.

Types of low voltage circuit breakers

Circuit breakers for power distribution are used to connect or disconnect the low-voltage load circuits and the main switch of the power supply, to prevent the whole circuit from being damaged by other equipment due to the failure of the power supply.

Motor protection circuit breakers are mainly used for overload, underload and leakage protection of motors to ensure that the motors can be protected quickly and effectively under abnormal conditions and to improve the safety of motors.

Lighting circuit breaker is used for 5A~50A current lighting system, its function is relatively simple compared with other low-voltage circuit breakers, just control the normal range of current in the circuit.

Leakage protection circuit breaker in the family circuit is more common, when we in the daily use of the process of circuit abnormalities can protect personal safety and fire due to leakage.

How to choose a low-voltage circuit breaker?

Rated voltage and rated current: When choosing a low voltage circuit breaker, it is important to note that the rated voltage and rated current of the low voltage circuit breaker should be greater than the rated voltage and rated current of the circuit or equipment. This is to ensure that the low voltage circuit breaker can work effectively within a reasonable voltage and current range.

Breaking capacity: Ensure that the breaking capacity of the low-voltage circuit breaker should be greater than or equal to the maximum short-circuit current that may occur in the circuit to ensure that when a short-circuit occurs in the circuit, the low-voltage circuit breaker can quickly cut off the power supply to protect personal safety.

Protection characteristics: according to the specific use of the selection of the appropriate use of the category, in addition, you had better refer to the circuit or load to provide the protective characteristic curve to select the appropriate protective characteristics, and the short-circuit characteristics and sensitivity coefficients are verified to ensure that the low-voltage circuit breaker can cope with a variety of fault conditions.

Attachment selection: general low voltage circuit breaker will have certain accessories, such as auxiliary contacts, shunt coil, etc., you have to choose according to your actual use of the process of the problems that may arise and other requirements of the low voltage circuit breaker, not the more the better.

Problems that may occur in low voltage circuit breakers and solutions to them

1. Manual operation can not be closed: when the need to restart the low-voltage circuit breaker manually pull down the handle, but can not be stabilized at the time the circuit is connected.  

Possible causes: poor contact with the coil leads, energy storage spring damage, no power to the circuit, loss of voltage release coil damage.

Solution: Check whether the coil of the low-voltage cutoff protector is damaged, whether the off-trigger is flexible, whether the circuit is energized, and find out the parts of the failure to carry out specific repairs.

2. Possible reasons for electric operation not closing: the operating power supply does not meet the requirements, the solenoid is damaged or too small or the motor positioning switch inactivation.

Solution: replace the operating power supply, check the use of solenoid, solenoid problems and then decide to replace or adjust the solenoid, repair motor positioning switch.

3. Possible causes of overheating of low voltage circuit breaker: pressure between contacts is too small, poor contact or wear on contacts. Loose joints of conductive parts.

Solution: adjust the contact pressure or replace the contact spring, replace the contacts, tighten the screws, remove the surface oil and oxidized layer.

4. Low-voltage circuit breaker burned possible causes: transient current is too large, the coil internal magnetic field generated by the induced current, lightning strikes, grid inrush.

Solution: use low induction coil of low voltage circuit breaker, install over-voltage device to protect low voltage circuit breaker, timely maintenance of low voltage circuit breaker.

Conclusion

Low-voltage circuit breaker is an important guarantee to protect the normal use of the circuit, through the above we mentioned how to choose the right low-voltage circuit breaker for you, I believe you have a new understanding of how to choose a low-voltage circuit breaker. When you are using low voltage circuit breakers will inevitably appear a series of problems, we have mentioned in this article low voltage circuit breakers will appear common problems and solutions, I hope to help you.