View Single Post
Old 03-02-2021, 01:34 AM   #18
Frosty
Guru
 
City: US PNW
Join Date: Nov 2018
Posts: 943
Quote:
Originally Posted by Aussie Mike View Post

All I can hear is the fridge fan running for about 2 mins then cuts off, the compressor then seems to hum for about 2 secs and stops and the fan starts again. That cycle is repeated over and over.
Sorry if I'm posting too much info. Anyway.

I was doing a bit more reading about the 1-flash and diagnosis, just to see if anything would jump out at me. I think something has. If you want to "skip ahead," just compare your bolded quote just above with the bolded section below. I think we have a match.

I posted some Penguin instructions way up at the top of the thread, and several refrigerator troubleshooting documents repeat that. But here Coastal added a bit of their own verbiage above that same advice:

Power supply testing on Danfoss DC powered refrigeration systems

To properly test the power supply to a Danfoss powered 12v or 24v system, the following testing procedure must be carried out
[Note: This is the procedure I posted upthread a ways from Penguin]. This will establish whether the power supply feeding the system is free of bad, loose and/or high-resistance connections.

Reading the voltage on the panel or at the batteries is meaningless, as is the fact of a new installation or new batteries. Size and the capacity of the battery bank is irrelevant.

It kind of made me chuckle because of course they have heard people saying "But my battery bank is in great shape and the voltage is good (I'd probably say the same, so not dissing you at all ).

Anyway, next I read through the standard info again, and then at the bottom they had added "Interpreting results" (of the tests I mentioned yesterday). Look at what it says will happen if you get into a cut-out/cut-in "vicious cycle" due to low voltage (the part I emboldened). It kind of matches the part I emboldened in your quote at the top of this post. (This would be with the 1-Flash issue.)

Interpreting results

▪ If the power supply is free of loose, bad, and/or high resistance connections, the voltage reading at “5” above will stay very stable and only drop slightly when the compressor starts. As a general rule, on a 12v system the reading should not drop below 12v.

If, when the compressor attempts to start, the voltage reading drops significantly, a bad electrical connection should be suspected. If the voltage drop is sufficient to fall below the 10.5v (23v) cut-off built in to the controller, the compressor will stop. (At this point the voltage may return to it’s original reading.) The fan or pump will continue to run for approx. 45 seconds and then the compressor will attempt a re-start. If the voltage is then above 11.5v (23.5v) the compressor will start or attempt to re-start again.
WARNING If the multi-meter being used is a digital model that is slow to react, the voltage may drop below 10.5v (23v) and then recover too quickly to register on the meter. This can lead to the situation where the compressor starts then stops from low voltage, the voltage returns to it’s original value, and there being no significant drop on the meter.

▪ If the compressor starts and runs OK but stops after a short while, the voltage may be gradually dropping towards and below the 10.5v (23v) cut-off point. This should be easily identified on the meter.

▪ If the nature of the fault is such that the voltage reading at “5” above drops below 10.5v (23v) even before the compressor attempts to start, a very bad electrical connection must be suspected. This is because even the small load of the fan or pump relay, both less that 0.5 amp (0.25 amp), is seemingly sufficient to reduce the voltage considerably.


************************************

Additional info from same document. These possible issues would be in addition to the possibility of too-small wiring. But they would be more likely to "crop up" after awhile as connections age (have you always had the problem at anchor or is it new?).

What to look for

A loose and/or high-resistance connection can be anywhere in the supply between the batteries and the controller. i.e. a bad breaker or fuse, a loose or corroded screw connection, a poorly made or corroded crimp connection, a damaged section of wire, etc. HINT A good place to look first is the negative (ground) connection, especially on a European-built boat. These tend to be multiple, common connections that are added to over time.


Hope this helps and is not too much.

Frosty
Frosty is offline   Reply With Quote