Frigoboat freezer problem

[Richard Kollmann]

redsky49 ,

It sounds like you are describing either refrigerant volume or refrigerant flow as cause of poor performance . For me to know about correct refrigerant volume in your system I need the answer to these question. I do not need to know how thick frost is on evaporator but where in the system is there frost and where there is no frost. Example this would be frosted areas on a correctly performing correctly charged system:

• No frost near compressor or filter on suction line.
• Line from compressor to keel cooler warmer than +15 degree F
• Line from keel cooler and collector to evaporator should be less than +15 F
• Very important, evaporator’s complete surface needs to have at least a thin layer of frost. If frost can be picked under your finger nail that area has frost. If frost is not detected covering at least 85% of evaporator’s surface area refrigerant charge is low or contaminated. Contaminated refrigerant can be indicated by large surface area of evaporator without frost but frost on return line.
• Refrigerant return line outside refrigerated area on its way back to compressor will be cool but no frost on line or at line connectors. Exception in cold weather a foot or two of frost near refrigerated box is normal.

Frigoboat has known for over ten years that the design of filter location has allowed refrigerant blockages to occur at refrigerant expansion capillary tube device. If cap tube restriction turns out to be your problem of reducing refrigerant flow Frigoboat can advise you of a temporary and permanent fix.

The only source of compressor cooling on these Keel Cooler models is returning refrigerant and if there is lack of evaporator cooling and little or no compressor off cycle time it is easy to understand compressor’s higher than maybe normal temperatures. Normal compressor dome temp when under a heavy load is around 130 degrees F.

O rings do have a shorter life if used between compressor and keel cooler (condenser). Frigoboat systems seem to me to operate five years in a live aboard boat before major rework or replacement is required.

[tomfl]

Originally Posted by Richard Kollmann

redsky49 ,

SNIP
Frigoboat has known for over ten years that the design of filter location has allowed refrigerant blockages to occur at refrigerant expansion capillary tube device. If cap tube restriction turns out to be your problem of reducing refrigerant flow Frigoboat can advise you of a temporary and permanent fix.

SNIP
Frigoboat systems seem to me to operate five years in a live aboard boat before major rework or replacement is required.

Kinda a little OT, but this is the first I have seen this criticism of the Frigoboat system.

I am in the process of selecting a replacement for the refrigeration system on my boat, a 1995 Seawind. After modifying the ice box by adding insulation it is just under 6 CF.

At first I thought the Engel drop in would be my choice, but it is only good up to about 3 CF. A local refrigeration tec suggested a Frigoboat system. The PO, who seems to know what he is talking about has suggest a Norcolder™ SCQT 4407.

The two guys I buddy boat with both have Technautics CoolBlue systems and claim they are worth the additional cost.

I currently have a small Engle portable that I bought before my old system died, the theory being that when cruising if I caught a big tuna or my limit of lobster every day for a week I could freeze the food. It is also nice to have the Engle in the salon so I don't have to go below deck to get a soda or cold water.

[s/v Jedi]

The Frigoboat units are great but had some trouble with earlier units. Mine are from 2005 and good. There is this stupid position of the ridiculously small filter drier but that is easily remedied by putting a regular filter-drier between the keel-cooler and the evaporator. I have one ready to go there, and even a spare evaporator, but still never used it. I may sell the spares again...

cheers,
Nick.

Originally Posted by tomfl

Kinda a little OT, but this is the first I have seen this criticism of the Frigoboat system.

I am in the process of selecting a replacement for the refrigeration system on my boat, a 1995 Seawind. After modifying the ice box by adding insulation it is just under 6 CF.

At first I thought the Engel drop in would be my choice, but it is only good up to about 3 CF. A local refrigeration tec suggested a Frigoboat system. The PO, who seems to know what he is talking about has suggest a Norcolder™ SCQT 4407.

The two guys I buddy boat with both have Technautics CoolBlue systems and claim they are worth the additional cost.

I currently have a small Engle portable that I bought before my old system died, the theory being that when cruising if I caught a big tuna or my limit of lobster every day for a week I could freeze the food. It is also nice to have the Engle in the salon so I don't have to go below deck to get a soda or cold water.

[Streetcar]

Follow up:

I seem to have a working system again. I got the system vacuumed for about 2 hours (the limit of Marshallese patience) and recharged.

I also adjusted the mechanical thermostat grub screw (2 turns clockwise) to raise the switch off temp to about -5C at the warmest setting (No 1).

The system was slightly overcharged with frost on the return line from the evaporator, so I leaked some off. Now the unit cycles on and off and does not seem to 'stall'.

The only issue I now have is that if the unit is left switched off for more than a few hours it does 'stall' (compressor runs but evap plate freezes and then defrosts and stay like that) when restarted. I have found that switching the unit on and off with 1/2 hour intervals eventually gets it going.

On this last point the local 'technician' here has a theory: the oil in the refrigerant drains down to the lowest point (keel cooler) and collects there. It takes several attempts at starting the compressor to get it moving around the system. Not sure if this is plausible...

[s/v Jedi]

Do you get error codes?

To start from a warm box, I normally put a bag of ice in it to help.

[Anna Sail]

I have been selling Frigoboat systems for several years and find them to be great systems, especially for the self-installer.

Rule No 1: Never introduce anything into a Frigoboat Keel Cooled system except for pure R134a. No leak detecting fluid, no leak stopping agent, no extra oil, no "conditioner", no Thawzone. Use only pure R134a.

Something to bear in mind - statistically, the more Frigoboat Keel Cooled systems there are in operation, and the older they get and the harder they are pushed, the greater the chance of reported problems. From analyzing these reports, and as part of Frigoboat's policy of ongoing development, several internal design changes have been made over the last few years in order to extend the service life of the systems, while increasing the reliability rate. This has resulted in the current systems being substantially less prone to cap tube and other issues than previous generations, particularly after several years of service in very low temperature applications. In addition, although not influential in the vast majority of applications, a Filter/Drier was added to the liquid line of all Keel Coolers last year as a further preventative measure.

Originally Posted by s/v Jedi

The Frigoboat units are great but had some trouble with earlier units. Mine are from 2005 and good. There is this stupid position of the ridiculously small filter drier but that is easily remedied by putting a regular filter-drier between the keel-cooler and the evaporator. I have one ready to go there, and even a spare evaporator, but still never used it. I may sell the spares again...

cheers,
Nick.

[Richard Kollmann]

Anna Sail, can you be more specific about the internal design changes made by Frigoboat to their keel cooler systems, and are they offering any retrofit kits to improve reliability of older units, if so what are the costs to retrofit? My records show major problems with this unit to be in filter/dryer location and O ring leakage at line connecters.

[Anna Sail]

Richard, I can't be more specific about technical updates to the Frigoboat systems because I'm not a Frigoboat designer, just a dealer. I know that there are 10s of 1000s of Keel Cooler systems out there, the world over, and that when an issue is detected, it is addressed and fixed, as any manufacturer is obliged to do if it wants to maintain its good name and reputation.

[Stingo]

Anna or Richard

Do you have a website where I can order a few spares seals?

[Tim R.]

I have a a Frigoboat K50 keel cooled model and have experienced connection seal failure and cap tube blockages. I have replaced the seals and installed the filter/drier last fall and have not yet had a cap tube blockage. We love our unit and it works very well for us. It is easy to diagnose and work on.

I also need to purchase some spare seals.

[Anna Sail]

Please go to www.Frigoboat.com to find a dealer in your area

[s/v Jedi]

Originally Posted by Tim R.

I have a a Frigoboat K50 keel cooled model and have experienced connection seal failure and cap tube blockages. I have replaced the seals and installed the filter/drier last fall and have not yet had a cap tube blockage. We love our unit and it works very well for us. It is easy to diagnose and work on.

I also need to purchase some spare seals.

When you saved the plugs and caps that were on the lines of each component, you will find an O-ring on each plug. I also believe they are a standard size so you can match them in any hardware store.

[Richard Kollmann]

Originally Posted by s/v Jedi

When you saved the plugs and caps that were on the lines of each component, you will find an O-ring on each plug. I also believe they are a standard size so you can match them in any hardware store.

There are a dozen different materials used in the manufacture of O rings so finding one that is right for 134a and POE or PAG oil may not be as easy as you think. Another consideration on keel cooler system is selecting an O ring material to handle high pressure line heat on connector before keel cooler. You must also know the shelf life of O ring you have on hand or the one you are purchasing, Safe shelf life in the past for O rings was less than one year.

[Streetcar]

Just to follow up on this..

The original problem has re-occurred every time I switch the system off for more than a couple of hours. When I switch back on, the plate freezes for about 10 mins and then it seems the capillary blocks and no more freezing on the plate. The only way to get it going again was to evac the system for 24hrs and recharge it.

I think that I have now solved it. New evaporator plate (and cap tube). What happened is that I got someone out to evac the system and recharge it as above and they suggested also backflushing it to remove any possible blockage in the cap tube. What I didn;t know at the time was that they were going to do it with Nitrogen instead of refridgerant. The pressure of the nitrogen inflated the plate like a balloon, so they agreed to replace the plate. Now it all seems to work fine... for now...

My guess is that, as was suggested right at the beginning of this thread, debris blocked the cap tube at the end nearest the compressor. Evacuating the system was enough to dislodge it so I could get going again but it was only ever a temp solution.

Probably the best longterm solution would be to also install a dryer between the compressor and the beginning of the cap tube to stop any more debris finding its way around the system.

[hpeer]

Old thread but I have a similar problem, with a twist.

The Frigoboat unit (2006) previously had a condenser leak. That was changed out and the system worked fine for a few years. This fall we had frost up to the condenser. A technician did an extensive evac and refill procedure that took most of the day. He also installed a dryer. It then seemed to work fine. We left the boat with the unit off for two weeks.

Upon return we have a new problem. The unit works fine for maybe 12 hours but then doesn't want to shut off. From a near warm box I've adjusted the temp control to a high level (6.4 ish.). Then when it runs continiously I turn it down until the compressor stops. Then it cycles for about 12 hours befor it keeps running. In last adjusted it to 5 at 5 am this morning. It's now 9 and haven't kicked on.

We are in St Augustine and its humid. We tend to be in and out of the box a lot. I'm wondering if ice buildup on the thermostat tube could be interfering with how well it senses and if a digital thermostat might be the solution.

I should add that I had an old speed controller that I recently replaced with a Merlin unit. The old unit worked in auto but would not shift into manual mode so I wanted to replace it befor the rest of it went bad. The system works the same with both units.

I get ice over all the evaporator surface. None outside the box.