Its annoying when for no apparent reason a Circuit Breaker trips, without getting too technical here is it in a nut shell.

A circuit breaker - is designed to monitor over current.  This Breaker will not have a test button on it.

A Safety Switch - is designed to monitor total current through the 2 wires to the outlets and if they are not within 0.03 of 1amp ( or 30 Ma ) difference the switch will trip.Physical size has no real bearing on its ability to trip or its capacity.This breaker will have a test button.

 When the difference occurs its a leakage to earth or via Your body to earth hence why its called a safety switch.

 Problems usually occur in heating equipment like Dryers, kettles and Dish Washers, Sometimes these appliances can be leaking a tiny amount that’s when the addition of the appliances on the circuit can cause nuisance trips. If your Breaker or safety switch trips randomly Call an electrician as we can test your appliances and make changes to the switch board to reduce the chances of it happening again.

  You can down Load this handy Flow chart to help solve the issue.