Dryer has an electrical fault.
If trips out whole house then it's a leak to earth tripping the RCD breaker and your dryer is dangerous.
If it just trips out your power circuit then it's taking excessive current and potentially dangerous.
Either way leave it unplugged and get it repaired, replaced etc.
The door has an interlock switch that acts like an on/off switch - as soon as it closes the heater, motor and fan are allowed to operate.
Peccavi
December 2008