earth leakage circuit breakers

No matter what the Distribution Box , which any one of the earth leakage circuit breakers have such a logo.

"Press once a month" means that you should press this button at least once a month, and when this button is pressed, the Circuit Breaker trips to verify that the earth leakage protection function is valid. This is a test button.

In actual use, there is no one to press once a month, but it is best to regularly check to find the earth leakage protector fails. If you press the test button, earth leakage protector should trip, otherwise it is broken. However, when the button is pressed, the time should not be too long, and the trip must be let go immediately. Otherwise, the experimental resistance in the leak will burn.