Refrigerator...Scratching My Head...

[Nick in Manitou]

UPDATE 4-26-20:

As soon as the "Customer Experience Manager" at Summit Appliances saw a photograph of how the unit was installed he said, "I can tell you right off the bat that the problem is the installation and the panel installed on the door."

Unfortunately moving the refrigerator into the middle of the galley floor and letting it function there for several days did nothing to improve its performance.

I wish he had been correct; I could have worked with that...

When moving the unit to the middle of the room didn't correct the problem he said, "The cooling system could have been compromised already because the unit was built in when it is not meant for this application." That might be correct...but the unit has no problem lowering the temperature in the box...it certainly seems like a control problem to me.

I asked him for a schematic that shows the circulating fan that exists in this unit and his response was the one I already have was all that they have. I said that my experience in manufacturing medical and radio broadcast equipment made me believe that somewhere there was a wiring diagram or schematic for this unit with the circulating fan (and perhaps other components that we can’t see that could be causing problems). I asked if he could check with the folks in Slovenia where the unit was manufactured. His response was that this model had been discontinued (after several folks at their company had said that it was the same as the current model FFAR10), but that he would try.

I got a response from the "Customer Experience Manager" that the factory said that the schematic that does't not show the circulating fan [and who knows what else] was all that the factory had. He said that our model has been discontinued.

To my surprise, he said that he realizes that we have already had multiple thermostats in the unit, but that perhaps we should try another...and he is sending one at no charge. (It sounds to me as though he had a conversation or two with knowledgeable folks at his company and no one could figure out any other probabilities.)

So, I await the arrival of thermostat #4. After installation, I will report the results and if need be, I will move forward with some of the other suggestions made by other forum members.

Thanks for your help and patience! The saga continues...

Nick

 

[Nick in Manitou]

Update: 5-11-20

The 4th thermostat came from the manufacturer. It was installed and performed just as the previous ones have, with the refrigerator cooling down into the mid-20s(F) before we intervene and either whack the thermostat with a screwdriver handle or just turn the unit off for a while.

I tried the suggestions Meteor64 made - both disconnecting the wire coming down to the compressor relay from the thermostat (the compressor stopped immediately) and whacking the relay in case it was stuck (no response).

I have checked with Danfoss, the manufacturer of the thermostat and the "cut-out" (compressor off) temperature range for the model thermostat that the refrigerator manufacturer says is the correct is between 17.6(F) and -14.8(F). When I pointed out to Summit that this seems pretty darn cold for a refrigerator, they said that the capillary tube senses the temperature of the evaporator plate and not the air temperature inside the fridge.

OK, so I have learned something...

So, now I have to figure out how to find where the other end of the thermostat capillary tube is supposed to be in contact with the evaporator plate and if it makes the contact it is supposed to.

(I am getting more and more tempted to get a line voltage thermostat that would sit inside the refrigerator, sense the air temp and turn the compressor on and off. If anyone has any experience with a thermostat that would work in this application, I would be interested in hearing about it. But I suppose that I should disassemble the interior of the fridge a bit more and see if I can locate the intended contact point between the thermostat capillary tube and the evaporator plate.)

Nick

 

[SKYCHENEY]

Update: 5-11-20

The 4th thermostat came from the manufacturer. It was installed and performed just as the previous ones have, with the refrigerator cooling down into the mid-20s(F) before we intervene and either whack the thermostat with a screwdriver handle or just turn the unit off for a while.

I tried the suggestions Meteor64 made - both disconnecting the wire coming down to the compressor relay from the thermostat (the compressor stopped immediately) and whacking the relay in case it was stuck (no response).

I have checked with Danfoss, the manufacturer of the thermostat and the "cut-out" (compressor off) temperature range for the model thermostat that the refrigerator manufacturer says is the correct is between 17.6(F) and -14.8(F). When I pointed out to Summit that this seems pretty darn cold for a refrigerator, they said that the capillary tube senses the temperature of the evaporator plate and not the air temperature inside the fridge.

OK, so I have learned something...

So, now I have to figure out how to find where the other end of the thermostat capillary tube is supposed to be in contact with the evaporator plate and if it makes the contact it is supposed to.

(I am getting more and more tempted to get a line voltage thermostat that would sit inside the refrigerator, sense the air temp and turn the compressor on and off. If anyone has any experience with a thermostat that would work in this application, I would be interested in hearing about it. But I suppose that I should disassemble the interior of the fridge a bit more and see if I can locate the intended contact point between the thermostat capillary tube and the evaporator plate.)

Nick

My walk-in cooler at my store has a line voltage thermostat on the wall. It looks like this:

https://www.grainger.com/product/WHITE-RODGERS-Line-Voltage-Mechanical-Thermostat-1RC43

 

[Nick in Manitou]

Sky,

That thermostat looks like it might work if I don't succeed in getting the one now in the unit to work as it is supposed to by sensing the temperature of the evaporator plate.

I have made a note of the one you suggested!

Thanks!
Nick

 

[Nick in Manitou]

Update 6-1-20:

It turns out that the refrigerator is assembled such that one can't access the evaporator plate without taking a Sawzall to the case...you cant access it from the interior (I unscrewed everything that had screws in it!) and you can't access it from the back as the case seems to be spot-welded together.

The previous owner had told us that they had problems with it and just put up with it. They purchased the refrigerator new and I bet that after they had it installed and the galley customized and custom panels attached to the fridge door, they just couldn't face the hassle of taking things all apart to replace the unit - even if it was defective from the start. I don't know what else it could be other than that the tubing that conducts the capillary tube to its position against the evaporator plate must be improperly positioned. That MUST be it. (Maybe...)

The unit is designed to be in its cooling cycle for a while and then once it thinks it is cold enough, the compressor turns off and the interior surfaces that have had frost build up on them have a chance to warm up, the frost melts off and drains out and the cycle starts again eventually. (They call this "Auto Defrost".) This period of time where the system is not on is important for the defrosting of the cooling surface. When I tried to use the thermostat with the capillary tube within the interior of the refrigerator, the time between cooling cycles was not long enough and very quickly frost built up enough that the unit was running constantly and not getting very cold. I assume that using a thermostat that I would mount through the wall of the unit would cause the same frosting-up issue.

So the situation now is that although I was told by the folks who made the unit that the thermostat was not adjustable...but because I am stubborn, I tried to adjust it anyway and have succeeded to an extent. The unit goes below freezing, but not for long enough to freeze much of the contents...and then it warms up more than we would like for it to, but so far we have not had any issues of spoilage.

I may try fiddling with another adjustment screw I see inside the thermostat, just in case it changes the cut-in temperature, but supposedly that is permanently set on this model of thermostat.

So the biggest lesson I have learned through this effort is that the thermostat is supposed to sense the temperature at the evaporator plate and not within the interior compartment of the refrigerator...and that the tech support people although well meaning don't always have a clue about how their products work.

Nick

 

[doc g]

Bypass the current stat , drill a hole in the side of the unit and install a line voltage stat. Johnson Controls makes nice digital ones along with the analog type too. Oh and manually defrost as needed........Pat

 

[Nick in Manitou]

Skycheney and Doc G have both suggested thermostats that would sense the internal temperature of the refrigerator and cycle it as needed...

My impression from running the refrigerator with the capillary tube within the conditioned space of the refrigerator instead of inside the wall of the unit is that within a day the interior back wall frosts up to a point where the unit runs continuously and needs to be defrosted. I think that the basic design of this unit precludes effective use of that sort of thermostat. Perhaps if we had the boat in Arizona...

Nick

 

[whoover]

Hello Nick, I'm just going to throw this out there. Have you thought about an external timer that would cycle the unit, two hours on, one hour off setup. Its a work around but it may work and stop the head scratching. My other suggestion is a one way boat trip.

Walt Hoover

 

[tonytrakovich]

How about a line voltage digital programmable thermostat. You can set the cut in and cut out temps independently. I would guess you would mount The thermostat on the back wall where frost builds up. There the compressor would not cut in till frost has melted.

Amazon about $35

 

[Boatsb]

I cant believe how long this has been going on. I'd have had it at the dumps or the manufacturer headquarters already.

 

[krush]

is that within a day the interior back wall frosts up to a point where the unit runs continuously and needs to be defrosted. I think that the basic design of this unit precludes effective use of that sort of thermostat. Perhaps if we had the boat in Arizona...

Nick

Is there a freezer portion on this refrigerator? If there is no freezer, you should not have permanent frozen stuff.

 

[Nick in Manitou]

Responding to several (good) suggestions...

Krush, There is no freezer compartment in this refrigerator. Supposedly it has an over-sized compressor and extra insulation so that it can meet some certifications for storing medicine (per the manufacturer). I honestly think that there was an error made when this unit was assembled and the device intended to hold the capillary tube to the evaporator plate was mislocated. (The previous owner of the boat purchased this unit new and said they just put up with the fact that it wanted to freeze everything. I never asked him if the problem existed since the unit was first in operation.)

Tony, I have looked into digital, programmable line-voltage thermostats and they all seem to be set up for household temperatures - none that I have found operate in the 30° to 40° F range.

Walt, The idea of a line-voltage timer that we could set through trial and error to whatever on-off cycle timing would be satisfactory had not occurred to us. I may resort to that!

Skycheney and Doc G have both suggested refrigeration-type thermostats and I was picturing having continuing defrost requirements due to short-cycling, but as Tony suggested in his post, if I attached the sensor to the back wall (where the frost builds) perhaps that would work!

Still fiddling with the stock thermostat (adjusting what they claim was non-adjustable to see if I can outsmart the engineers - rather doubtful, but I am stubborn!

Nick

 

[jim rosenthal]

I have to say, I'm with Scott on this one. I'd have it off the boat by now and something modern from a local shop with a warranty.

The funny thing is that Summit fridges are all over the place in medical applications and work fine. Not this one, evidently. And you're not the first person to have difficulty with one on a boat. I think we have another forum member who's had trouble with Summit units, seems to me.

 

[sixty]

I see you are have in issue finding a thermostat. My boat used a Ranco analog thermostat for the freezer plates that had a huge range of temperatures and was really accurate. Look at the Ranco model ETC-111000. Its digital, works on 120v and has a range of -30 to 220 degrees. They run about $60 online. Use this to bypass the fridge thermostat and it should fix your issue with proper sensor location. Your fridge wiring is simple so this should be pretty easily accomplished.

 

[Nick in Manitou]

Sixty, That looks like another possible option if I get to the point of drilling through the side of the unit.

Nick

 

[oscarvan]

Sixty, That looks like another possible option if I get to the point of drilling through the side of the unit.

Nick

BE VERY CAREFUL DRILLING IN A FRIDGE!!!!!!!!

(I will never again).

Many fridges, and especially freezers use the skin of the appliance as a cooling surface. There is actually refrigerant running inside. Drilling will result in PSSSSSST! and the last post in this thread will be about how you got it out, and the new one in.

Ask me how I know......

 

[Nick in Manitou]

Very pleased to say that with adjusting the screws within the thermostat, we have achieved success.

The unit has not frozen anything for more than a week and a half and the temperature range is fine.

Stubbornness seems to have paid off this time!

Thanks for all the suggestions and support.

Nick

 

[SKYCHENEY]

Very pleased to say that with adjusting the screws within the thermostat, we have achieved success.

The unit has not frozen anything for more than a week and a half and the temperature range is fine.

Stubbornness seems to have paid off this time!

Thanks for all the suggestions and support.

Nick

Glad to hear you finally fixed it.