Aircon circuit. Conductor and breaker size ?

[Derlyn]

So you do an inspection for COC.
You find an aircon circuit wired with 1.5mm wire protected by a 20A breaker. Problem.

Now you have 2 options.
A. Rewire the circuit with 2.5mm wire or B. Change the circuit breaker to 16A.

Using a clip on tester you measure the current drawn by the unit is 5.8A.

Would you quote to do A or B above and why ?

[GCE]

Think couple of more questions before giving a definite answer

What is start up current , has the aircon maybe been changed to an inverter type along the line

Would think that if it is still old aircon that somewhere along the line there was intermittent tripping and the CB was upgraded

Problem with downgrading ,and it was an intermittent trip , you could be back there in the next month doing a rewire of the circuit at your own cost

[Justloadit]

Alternative use a 16A type D circuit breaker designed for motor starting

[BobZA]

Would also suggest 16A type D circuit breaker

But also try google the aircon installation manual and check out the recommended circuit breaker sizing, or at least the startup current if available

[AndyD]

Refer to manufacturers instructions. If they specify a 20A circuit you'll possibly void warranty if you downgrade it to a 15A circuit breaker.