Does the small circuit breaker have the function of preventing leakage and overload?

Miniature circuit breakers may include protection against leakage and overload, but this depends on the specific model and design. Here's a brief description of both features:

1. Anti-leakage function:
    - Circuit breakers that protect against leakage are often called residual current circuit breakers (RCD) or ground leakage circuit breakers (GFCI). They are capable of detecting current imbalances in circuits (i.e. current "leakage" from supply lines to ground lines). Once a leakage is detected, this circuit breaker will quickly disconnect the circuit, thereby protecting people from the risk of electric shock.
    - This type of circuit breaker is commonly used in bathrooms, kitchens, outdoors, and other environments where contact with water may occur.

2. Anti-overload function:
    - Anti-overload circuit breakers protect circuits from excessive currents. When the current in the circuit exceeds the circuit breaker's rated current, the circuit breaker automatically disconnects, preventing wire overheating and potential fire risks due to overloading.
    - This type of circuit breaker is a very basic and necessary component in an electrical protection system.

When selecting a miniature circuit breaker, make sure it has the required protection features. Some circuit breakers on the market may integrate both anti-leakage and anti-overload protection, while others may need to select products with these functions separately. Before purchasing, it's a good idea to confirm the product's specifications or discuss it with the supplier to ensure you choose a circuit breaker that meets specific safety requirements.