Hi all

Thought this may be of interest to my brothers.

Recently, I issued a COC for a domestic installation with 6 plug circuits, each protected by a 20A CBI circuit breaker.
All inspections and testing were carried out by the book and no faults were found on any of the plug circuits.

I make use of a resistive load on all socket outlets that draws 15 Amps. All passed with voltages within limits whilst under load.

COC issued after minor repairs attended to and I was very confident that the installation was compliant.

A week after the new owner moved in, I get a call. Plug circuit breakers are tripping.
Drop everything and go and have a look.

3 of the plugs circuit breakers could not handle the instantaneous starting current drawn by an angle grinder. These 3 circuit breakers could handle the 15 Amp resistive load, but couldn't handle the starting current of an angle grinder.

Replaced the circuit breakers and problem solved.

Fortunately, the new owner understood that this problem could not be detected even by doing the testing by the book.

From now on, an angle grinder is gonna form part of my testing kit.

Peace out ... Derek

Peace out