Re: [Amel Yacht Owners] Aft Cabin Air Conditioning Tripping 220 Volt Panel Fuse & marina

Bill & Judy Rouse <yahoogroups@...>


Here goes, I will attempt to explain, but frankly Eric is much better at this because he is an electrical engineer. My explanation assumes you are connected to EU type shore power...If not, 1.) let me know and 2.) try running the AC with your generator and let me know the outcome.

A GFI Circuit will OPEN when there is an imbalance between the HOT wire (Brown) and the RETURN (Blue) within a particular circuit. Most GFI's are set to OPEN when current difference between HOT and RETURN exceeds 5mA, but I have seen some marinas set it at 1mA.

For practical purposes and on your Amel, this normally will happen when the RETURN (Blue) comes in contact with EARTH, reducing the current on the RETURN side and causing an imbalance between the HOT and the RETURN. Of course it can happen with the HOT, as well.

On a boat, the normal conductive material between NEUTRAL and EARTH is water. With the Water Heater, it is the heating element cracking with age that allows some HOT current to escape to EARTH. This causes an imbalance and OPENS the GFI.

If a capacitor  is getting hot, that heat is a sign of used current and enough used current by a capacitor will certainly cause an imbalance which will OPEN a GFI.

So, what would I do under the circumstances you describe:
  1. I would eliminate the pump as a suspect because the other ACs work fine - done
  2. I would inspect the faulty AC for any water leaks and full condensation pan - done
  3. I would test and/or replace the two compressor control capacitors...1 each: 40 microFarads 420 volts to 470 volts (Biggest physical size) and 1 each: 10 microFarads 420 volts to 470 volts (Medium size)
  4. If I still had not solved the issue, I would try changing the setting on the timer. 
  5. If that doesn't work swap the timer with a working unit. The timer is about 13-15mm square and about 40mm long. It has two wires and is adjusted with a flat blade screwdriver.
  6. If none of the above works, I would get a recommendation for a Climma Qualified Tech.


CW Bill Rouse
Admiral, Texas Navy
Commander Emeritus
Amel School
720 Winnie St
Galveston Island, TX 77550

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