Do You Know The Role Of Circuit Breakers in Distribution Boxes?

Do you know the role of circuit breakers in distribution boxes?

 

Circuit breakers play a vital role in safety protection in distribution boxes, and their core functions can be summarized into the following three aspects:

 

1. Core function of circuit protection

 

- Circuit breakers provide overload protection:

When the line current continues to exceed the circuit breaker rating (such as the common 16A and 25A specifications in households), the bimetallic strip is bent by heat to trigger the tripping, cutting off the circuit to prevent the line from overheating and causing a fire.

 

- Circuit breakers can provide short-circuit protection:

When a short circuit occurs, the current surges instantly (up to thousands of amperes), and the electromagnetic release responds immediately (0.01-0.02 seconds to act), quickly cutting off the fault current to avoid equipment damage.

 

- Fault isolation:

After tripping, an obvious breakpoint is formed, and the circuit breaker physically isolates the fault section from the power grid to ensure the normal operation of other parts of the system.

2. Power distribution system management function

- Hierarchical protection system:

Through the three-level configuration of main switch (63-100A)-branch road (16-32A)-terminal (10A), accurate fault positioning is achieved and the scope of power outage is reduced.

- Maintenance operation interface:

Provides obvious disconnection points, and with the lock device, reliable power off can be achieved during maintenance to ensure personnel safety.

- Status indication system:

Through the mechanical indicator window (red/green) or digital display, the on-off status and fault type are intuitively displayed.

3. Extended protection function

- Leakage protection integration (with RCD type):

30mA sensitive action, cut off the leakage line within 0.1 second to prevent electric shock casualties.

- Voltage fluctuation protection (under/overvoltage release):

Automatically disconnect when the voltage exceeds the limit by ±15% to protect precision equipment.

 

- Remote control interface (intelligent):

Supports Internet of Things connection, realizes mobile phone APP monitoring and remote opening and closing operations.

 

Typical application scenario example:

When the air conditioning line short-circuits 2000A due to insulation aging, the electromagnetic releaser operates within 15ms, and the arc extinguishing chamber raises the arc voltage to above 800V, forcing the current to extinguish when it passes through zero. The entire process is completed within 1/4 of the power frequency cycle, effectively protecting the conductor (6mm² copper wire safe current 32A) from melting.

 

Selection points:

The lighting circuit uses the C-type tripping curve (5-10In), and the motor circuit should use the D-type (10-20In). It is recommended that the data center be equipped with an electronic adjustable circuit breaker to achieve more accurate protection coordination.