fridge recharge

[Thegoodshipmagn]

Hi

I have a frigoboat compressor which I want to add some refrigerant to.

I have a can of 134a and a gauge and nozzle, the nozzle is the 1/4 inch push fit variety which looks like it should fit my (low pressure) valve.
However when I try to push it on I cant seem to get it to go on, I just end up releasing more gas.

Am I just being a wus and need to push harder or are there a variety of valves and I have the wrong nozzel ?

thanks

Mark

[s/v 'Faith']

Mark,

There are the common "quick connect" r-134 automotive type connectors, and there are systems with schrader valves and threaded fittings. Is is possible you are dealing with a mix of the two?

[onestepcsy37]

yes there are a variety of valves. i found a 'valve kit' at walmart which has about half a dozen valves with different ends. think it was about ten bucks. one of those should allow you to fit your can to your low side valve. or go to an auto parts store.

my ten year old adler barbour, which came with r134a in it, still has the 'old fashioned' r12 valve. i found a small 'converter' valve which mates the r12 valve to the r134a can for about six bucks.

[Richard Kollmann]

How did you come to the decision you needed to add refrigerant? Is it because only part of evaporator’s surface area is covered with frost? Tampering with refrigerant can create a much more serious condition if you have not confirmed system is actually low. You must also use only pure 134a with no additive refrigerant. Your unit only holds 3 to 5 ounces of refrigerant and 15 grams above or below the correct amount will affect performance.

The standard fittings for 134a refrigerant are designed special for that refrigerant so you will need a conversion adapter fitting for most mobile refrigeration like Frigoboat units.

[Thegoodshipmagn]

Thanks for the quick responses.

It seems I am using the wrong connector so will need to look for another.

Richard, I had problems with my fridge last year after it was repaired in Sint Martin. They overfilled the system and it was cold but pulling 9amps, I slowly released refrigerant until it was cold and only burning 4.5/5 amps, however now we are back in the warmth again it has been running "a lot"
As I had a can of 134 I figured I would add some back to see if it made it more efficient.

Mark

[Richard Kollmann]

With the correct amount of refrigerant there will be frost covering at least 90% of evaporator's surface area and no frost on line leaving refrigerated box. Ambient temperature conditions will change performance especially on water cooled units. On well designed systems manufacturers provide the weight of refrigerant needed in grams based on standard day temperatures. Frigoboat uses the frost cover method.

Instead of writing my sixth edition of boat refrigeration books I revise them by additions to my web site. Serious problem additions are put into TECH TIPS other book additions are covered as general subjects. RREFRIGERANT CHARGE is main heading for servicing refrigerant. I started a Tech Tip on Frigoboat troubles by attempting to review 25 years of emails and forum posts and have not finished except to pin problems down to refrigerant leaks and refrigerant flow after in service for more than four years.