Problem with AC units
A problem has developed in my two Pompanette marine air conditioning units which is baffling me, and I hope someone with more knowledge will be able to suggest a remedy.
I will give a background as concisely as I can:
I have two identical 16,000 Btu marine AC units, one forward and one aft, fed by a single 120 volt water pump which splits to each unit. These units have run perfectly for three years. The water pump was submerged in a recent fresh water flooding, but I dried it out thoroughly, and it seems to pump as normal, and the flow through both outlets looks to be the same as it was before the submersion.
Afterwards both units ran as normal for about a month.
The recent problem:
The rear AC unit still works perfectly. But when I switch the forward unit on during the day it cools for about ten minutes, as I watch the voltage on my AC meter slowly rising, from a normal of about 11 amps, until it reaches 20 amps, then trips the 20 amps breaker, shutting down both units. Sometimes the forward unit just shuts down itself with a HPF reading, (high pressure fault), even before the rising amperage trips the breaker.
I then have to use only the rear unit, which is just keeping me sane, when it’s over 100F outside.
In the evening, (when the temperature in Florida is considerably less than during the day), both units run all night, the forward one only clicking the breaker as the ambient temperature rises in the morning.
Clogged condenser fins will restrict air flow and cause a HPF fault, but I have cleaned them with both compressed air and vacuum, and they don’t look any different to the aft unit fins.
The manufacturers told me a HPF fault is only caused by either a lack of water flow, or a reduced air flow. They cannot suggest why the amperage rises before it trips the breaker. It’s no good sending the unit back for inspection because they can’t refill it with R22, because the law has changed and they now use different freon.
One remedy would be to find a marine AC engineer, but being a cheapjack yachty I thought I would ask here and see if I can fix it myself.