Question

why the appliances does overload of electric consumption damage​

Answer 1

Exceeding the rated load for the circuit wiring causes the circuit breaker to trip, shutting off the power to the entire circuit. If there were no breaker in the circuit, an overload would cause the circuit wiring to overheat, which could melt the wire insulation and lead to a fire.

Answer 2

If in a device of a circuit ,there a lot of appliances connected then the over loading cause. That may burn and Cath fire in the whole circuit