Frozen line

[admiralslater]

I have been fighting the good fight with my freezer. It is a new box and lid with a frigoboat boat keelcooler ,and a variable speed controller. The plate is new this year and worked well on start up . I had put the thermostat bulb at the top of the freezer and it had been ok . After a defrost the unit would start and shut down so a local teck installed a dryer vacuumed the system and it was all systems go. While retrieving my box o wine (Martinique) I noticed an Ice ball on the line just out side the freezer . I thought that the thermostat location was the issue. I have been moving it around the freezer trying to settle the system down .Any ideas ?

[Lepke]

Insulate the line where the ball forms while the freezer isn't running. It should stop forming ice. It's the temperature difference and the moisture in the air.

[Typhoon]

Hey David ,

Was the system still on initial cool down when you noticed the ice ? Or had the system been cycling on and off as it should ? Its not unusual to get frost on the line just outside the box in a deep freeze application, just as long as it does not travel to far down the line . That would indicate a possible over charge of refrigerant in the system . Most techs tend to over charge these small systems . Let a little refrigerant out and watch what happens.

This box is strictly a freezer ?

Regards John.

[admiralslater]

Hello John, the ice was not on the initial cool down .the tube is insulated for about three feet and was full of ice . the ice ball that was just out side of the freezer was about the size of a golf ball . I had noticed a higher than normal amphere reading on my link 10 as well . After words I moved the bulb into the bottom of the freezer and it read -4 degrees f. I assumed that the high position of the bulb was creating a situation that the compressor could not keep up with. But now after what you said that may not be the case.
What do you consider a little gas release ? 1or 2 seconds for example .
When do you leave for Annapolis? I have never been to the spring show . The last time we had way too much fun . Good luck with your equipment
David

[admiralslater]

Yes it is only a freezer

[Typhoon]

Hi David ,

Yes we leave for the show on the 25th, its a 10 hr drive but we usually stop for the night on the way down.

If you say that your suction line is frosting up for three feet outside of the box this may indicate a slight over charged situation. You don't want that frost line to get to close to the compressor.

But as you say this is a deep freeze and you are getting temps down to -4F , it is working just fine. Maybe just a little over charged. Try giving it a release of 5 seconds at a time and watch the line. You may want to take of a little of the insulation off to ensure liquid refrigerant does not get back to the compressor and also so you can observe the frost line.

Where are you now David ? The weather is getting better up here now

Regards John.

[admiralslater]

Thanks for taking the time with this . We are in Bequia and leave for Grenada tomorrow via Cariacou. My freezer is about 1.8 cubic feet (too small) with a 26 x9 inch plate .
I have a Carel electronic thermostat and a frigoboat boat smart speed control . The thermostat bulb is 5 inches below the lid and it is keel cooled.the compressor is about 10 feet from the box.
The thermostat is set at 11 degrees and it and it reached that the speed controller is at idle
I have let out about 6 seconds of gas and it seems to be a bit better .
Right now I have a bit of ice at the box exit and heavy frost for about 2 feet . How long does it take for ....... I just checked again and the frost is retreating .
What is a reasonable temperature to set the box at and how many seconds of gas is do you think I could release.
I hope I don't need to email you again , and look forward to meeting you this summer so we can see what is to be done with my fridge up north .
Good luck at the show

[Anna Sail]

Hi David,
John is giving you good advice, however.... with a Frigoboat system, you don't want to see any frosting on the line outside of the box. This is a sign of overcharge, like he said. The insulation that is there is simply to catch any condensate, water drips that can occur when gas moves from a cold environment (your box) to a warm environment (outside your box). That you have frosting indicates that the liquid refrigerant hasn't completely evaporated, turned into gas, before it leaves your box; an indication that you have too much refrigerant in your system... as John has suggested. So, keep bleeding it off, a few seconds at a time. Seeing an inch or two outside your box is fine. Seeing more than that is not fine. Your compressor is designed to compress gas, not liquids. It's when the refrigerant flows to your keel cooler, where the heat exchange occurs, that it is converted back into a liquid, to flow back to your evaporator plate to absorb the heat, evaporating into a gas, etc.

Regarding your thermostat sensor - it should be mounted mid-way in your box, to measure average temperature. Bear in mind, warm air rises, cold air drops. A sensor at the bottom means the top of your box may be too warm and vice versa. But you may have figured that out already!

[Typhoon]

Originally Posted by admiralslater

Thanks for taking the time with this . We are in Bequia and leave for Grenada tomorrow via Cariacou. My freezer is about 1.8 cubic feet (too small) with a 26 x9 inch plate .
I have a Carel electronic thermostat and a frigoboat boat smart speed control . The thermostat bulb is 5 inches below the lid and it is keel cooled.the compressor is about 10 feet from the box.
The thermostat is set at 11 degrees and it and it reached that the speed controller is at idle
I have let out about 6 seconds of gas and it seems to be a bit better .
Right now I have a bit of ice at the box exit and heavy frost for about 2 feet . How long does it take for ....... I just checked again and the frost is retreating .
What is a reasonable temperature to set the box at and how many seconds of gas is do you think I could release.
I hope I don't need to email you again , and look forward to meeting you this summer so we can see what is to be done with my fridge up north .
Good luck at the show

Hi again David

Sounds like a small box but those are the easiest to manage in tropical conditions some people never have any freezer at all when south .

Ideal freezer temperature is 0F but depending on your box insulation this may not be possible . As box temperatures drop the ability of the system to remove heat drops as well so only a very well designed system in a well insulated box (R40) can reach those temperatures in the tropics with a small 12v Danfoss based system and still be efficient . You don't want your compressor to run steady .

If you can manage 50 percent duty cycle in a true deep freeze (0F) in the tropics you are in refrigeration heaven

Any Idea of your amp/hr use?



This being a mid temperature freezer at 11F in a small box it is not at all unusual to have frosting of the suction line just outside the box and if you stop it entirely you may not be running the system at peak performance .

As Anna says , an inch or two outside the box should be just fine . Just remember during the off cycle that bit of frost will melt and root any wood that may be around it, over time , also mold could become an issue so make sure that bit of water has somewhere to go .

You are going about it the right way , giving time between bleeding the gas. Just give it a squirt and let it rest for 20 minutes , check, and continue . Ten feet is a good distance so you shouldn't worry about slugging the compressor.

I will be down there in a month or so installing a system on Rick Moore's boat Sophisticated Lady maybe we could plan to be in the same area and have a cold one

Regards John.

[admiralslater]

In the last episode of "the &$$/:! Freezer " our intrepid cruiser in consultation with mission control ,was letting out gas in small increments in hopes of getting the heavy frost off the line from the box . After letting out about 10 seconds worth of gas over the course of several hours TA DA the box went to 11 with no frost ,so the only thing to do after this success was to try and get colder after all why need well enough alone .
So I lowered the thermostat to 9 F and sat back to enjoy the fun . Well the lights went out on the SSC will the thermostat still showed temperature decrease so the compressor was running . So being clever a restart was done (yes I waited a bit) and things looked normal until the dreaded fault light came on . An other restart and I went to bed .
What happened next you ask ? Well the next morning the SSC with no lights on ,and the compressor running the temp was 6f 3 lower than set ,I fiddled with the mode switch on the SSC and got it registering again . This is the fun part it went down to 4 f 5 lower than set temp. I turned off the freezer for several hours a reset the the temp to 10 degrees.
The SSC indicates running on low speed the temp noodles around the set temp . We shall see . I don't think I took out too much gas . Every time I touch the compressor it seems quite warm . Also how tight is the temp range on the thermostat ie will it wait for a degree or so before kicking in

[Typhoon]

Originally Posted by admiralslater

In the last episode of "the &$$/:! Freezer " our intrepid cruiser in consultation with mission control ,was letting out gas in small increments in hopes of getting the heavy frost off the line from the box . After letting out about 10 seconds worth of gas over the course of several hours TA DA the box went to 11 with no frost ,so the only thing to do after this success was to try and get colder after all why need well enough alone .
So I lowered the thermostat to 9 F and sat back to enjoy the fun . Well the lights went out on the SSC will the thermostat still showed temperature decrease so the compressor was running . So being clever a restart was done (yes I waited a bit) and things looked normal until the dreaded fault light came on . An other restart and I went to bed .
What happened next you ask ? Well the next morning the SSC with no lights on ,and the compressor running the temp was 6f 3 lower than set ,I fiddled with the mode switch on the SSC and got it registering again . This is the fun part it went down to 4 f 5 lower than set temp. I turned off the freezer for several hours a reset the the temp to 10 degrees.
The SSC indicates running on low speed the temp noodles around the set temp . We shall see . I don't think I took out too much gas . Every time I touch the compressor it seems quite warm . Also how tight is the temp range on the thermostat ie will it wait for a degree or so before kicking in

Hey David , Im not sure of what thermostat you are using . If it is a digital one and controlling box temperatures , I set mine at a 3 degree C variant . Shuts of at -18c and back on at -15c or 0f to 5f .

Sounds like you SSC is doing all sorts of strange things. Unplug it from the C and T terminals and plug in your thermostat directly. This will remove the SSC from the equation , see what happens . This will set your system to run at low speed . Give it a day running like that and see if your box temperatures stabilize. Im not of fan of all those electronic do dads , I like controlling the compressor speeds manually. Plus they seem to break a lot .

Regards John.

[admiralslater]

That's interesting about the range thank you . I have a Carel thermostat supplied by frigoboat. At the moment it seems to be ok and since we are hauling next week I may leave it be . The surprising thing to me is when it went so much lower than set !
With variable speed manually controlled I assume you start low get things going and crank it for the big load and then back it down as much as possible once it is running at the right temperature.
Where are you going to be working on Sophisticated Lady and when.

[Typhoon]

Originally Posted by admiralslater

That's interesting about the range thank you . I have a Carel thermostat supplied by frigoboat. At the moment it seems to be ok and since we are hauling next week I may leave it be . The surprising thing to me is when it went so much lower than set !
With variable speed manually controlled I assume you start low get things going and crank it for the big load and then back it down as much as possible once it is running at the right temperature.
Where are you going to be working on Sophisticated Lady and when.

Good morning David .

Yes that is basically what they do . But like every thing else on a boat they do break . I like to keep things as simple as possible . You know when you have loaded up your fridge so just flick the switch on the control panel and speed up the compressor your self . Simple , reliable .

I am hoping to rendezvous with Rick Moore in Grenada . Where are you going to be Admiral ?

Regards John