Every home has some type of circuit breaker in the meter/fuse box or an internal sub-box. The type depends on the age of the property. The circuit breaker or safety switch will cut the electricity feed if there is a problem.
The electricity feed follows a circuit, starting at the power station, then to your home and the light globe or appliance and back, minus the amount of electricity used. The RCD (Residual Current Device) is the safety switch or circuit breaker which cuts off power in problem situations within milli-seconds.
Many power outages are caused by the safety switch being tripped (turned off) due to a fault in an appliance – kettle, fridge, toaster, power board or lead – or by moisture reaching an electrical circuit.
If you lose power, it may be just lights or power points, check the safety switch. If it has tripped, it will be in the down position. If this is the case, try to reset the safety switch by pushing it up. If it trips again, disconnect appliances and electrical devices you have been using. If this causes the safety switch to now stay up, reconnect each appliance one at a time and recheck the safety switch after each appliance is reconnected, until you find the one that causes the switch to trip again. Don’t use that appliance again until it is checked and repaired by a qualified tradesperson.
If you cannot isolate the appliance causing the problem, call a qualified electrician.