Fridge and freizer trouble shooting

[kcj]

I have a Frigoboat twin bd50 freezer thAt was giving me fits for the year I had the boat. Ended up with pressure readings like yours, positive and negative. Solution was to pull a vacuum on the system for four hours, then close the gauges and monitor the pressure for an hour or so. If it remains constant the system is tight. If it moves you have leaks to resolve. If tight reload with gas and go.

I have not stayed in a holiday inn in a while and have no formal hvac training. I have read a lot of the forums, Kollmans book, and paid a lot of attention when a tech did the same thing 8 months the prior. I had been wrestling with my system up until the week of the departure. Ended up deciding to vacuum as described at last minute. Clearly not a decision to be taken lightly. But a good one as the system has been tip top for the 6 weeks since. KOW. Ymmv.

Btw I did have to sort out door seal issues (frost screws the units up) and clean out salt water strainers and pumps along the way. And having a sight glass made the refill much easier, as well As a warm empty unit. But there is nothing like understanding your own system.

Making ice in the keys

[ColdEH]

Sounds about right , but I think you actually may have moisture in the system and ice is blocking the cap tube . Hence the up and down swings . If it was a hard blockage it would just stay plugged . Hmmm how did the moisture get in ??? See how long the gas stays in ? If you lose it I think there may be a pin hole in the condenser ,
Thanks for the update . Do you have a vacuum pump on board ?

I have another idea , but let's see if the gas stays in first .

Regards

[kcj]

Well I do have a pump on board now! Thanks Amazon.

As to how moisture got in, in my case that was probably end user error and owner learning curve..

But I was fortunate , my system was tight. And if I was not clear, I consider Vacuuming a system the n+1 option out of n options.

[ColdEH]

Yeah I understand . Hvac is a steep learning curve . Lol . I'm still wondering where your refrigerant went ? Do you have any couplers that use a o ring as the final seal ?
If you vacuum and you are on shore power , let it run all night. You probably don't have a micron gauge to be sure you are getting down to 500 microns of vacuum . So you need to evac the system for a long time to be sure . Getting the moisture out of the oil takes a long time .
I hope you can save the system .

Regards John

[ColdEH]

Also , are you soldering or brazing ? Brazing cause a lot of scale in the tubing and you will need nitrogen to stop this , and purge . But if you are soldering in the new filter drier , what solder and flux are you using ?
Regards

[k9spud]

Up date
Purchased 2 wbd50f compressors, 200f and 380f with ss skin.
And 2 new thermostats
Pulled out old system today installing tomorrow.

Insulation on freizer back wall is 95 mm thick.

[ColdEH]

This is probably your best way to go . You may have got the old systems up and running only to have them fail again . Not fun when you are relying on them to keep your cruising stores fresh .

Regards

[k9spud]

Very happy with end result
Freizer thermostat on 2
Fridge on 4
Working like brand new
Amps used is a third of what it was when running alright before

[Rorzech]

Originally Posted by k9spud

Hi I am having problems with both.
Freizer is a salt water cooled veco superfrigomatic wbd50f with 400f evaporatore.
It's running continously and not cycling on and off.even with thermostat turned to just under 0 degrees Celsius. And less than a third of evaporator icing up.

Fridge is a salt water cooled veco wbd35f with a 200f evaporator.
Compressor runs and gets warm.
Doesn't cool the evaporator at all.
Small lines runnin into the saltwater cooling pipes don't get warm.

Tests performed
Power supply to both good at 12.8 volts.
All conections are clean.
Briged between thermostat posts (no change)
Led installed between small + and 2nd post below (didn't light up at allon either compressor )
Check led is working (it is)
Any advise on what to check before installing more gas.
As I understand I need to check all other options first.

Good advise on gassing in previous post

Great news that its working better than ever !