View Full Version : Main 32A Breaker tripping after a few minutes on a Toshiba RAV 160 AH-F

13-08-2014, 06:43 PM
I'm trying to remedy a fault that's occurring with a customers air conditioning.

It's a Toshiba RAV 160 AH-F matched to a RAV 453 CHE and was working fine. Now it runs for a few minutes and takes out the 32A mcb. I'm told by Toshiba it can only be the compressor and was wondering if there is a way to bring back life for another year?

I'm an electrician and not an air-con engineer, so any help/ advice would be greatly appreciated (I am aware that it's an old unit and that the R22 refrigerant will not be available after January).

13-08-2014, 07:35 PM

As you are an Electrician you will be familiar with using an Insulation Tester.

Switch the outdoor unit off and expose the terminals on the compressor connections.
Disconnect all wires and carry out an insulation test on any one of the compressor termnals to earth and see if the reading is one you would accept on your wiring installations.

As the compressor winding's break down, the insulation deteriorates and excessive amps are drawn, leading to mcb trips and eventually a dead short.

Nothing we as fridge engineers can do to prolong this for 1 year....bite the bullet my friend and get a pro in to properly diagnose and fix the problem.

13-08-2014, 10:40 PM
In addition to what frank has pointed out you really have to be so sure that your circuit breaker is indeed 100% working as well. I have encountered a few problems of units tripping circuit breakers where the problem was actually the breaker itself. You have to connect an amperage tester to the unit while it is running and see how much amps it is drawing. I also find it strange for someone not on site to make a diagnosis for you without having to physically carry out the necessary tests on the AC unit. Other components like fans, solenoids, etc can also trip the circuit breakers. More test need to be carried here before you are so sure that its the compressor or other components at fault.

The MG Pony
14-08-2014, 04:30 AM
As said as a sparky you should know that breakers do wear, throw a new breaker on, see if that fixes it, while at it check terminal torquing & voltage at reat and under load, give us the resualts then go from there. "Oh ya and the run amps! high amps can be cuased by a dirty conedencer to fyi"