Isotherm Cruise 85 caput.

[booster]

Originally Posted by GeorgeRa

No need to apologize, but thank you. Looking at the video I noticed that the bulb is not touching the freezer metal, there is some airgap.

See from 1:15

I need to place the fridge on the bench and do some work, fortunately fridge removal is easy.

Was your capillary bulb on the bottom of the freezer like that? Ours is just like I described and old one was.


You can put the bulb where ever you want to adjust the frig vs freezer temps. We want the freezer on the warmer side as then the frig is more efficient and we don't carry ice cream so we had ours mostly just stuffed in on top of the freezer box between the freezer and top of the frig. Our new one has vented cover around the box so no room on top now, but the side of the cover is vented and probe could be placed inside the cover along the side of the freezer box. That way you wouldn't need to loosen the freezer and move it at all. It could also go on top if don't have the cover on yours. Be aware you will likely have to adjust the coarse calibration screw in the thermosat itself. It is a torx screw, very small, you get to through the open end. I don't recall which way is warmer and colder though, unfortunately. You probably want to leave the adjusting unit loose until you know you like the temp range and be sure to get the right little torx L wrench. Practice to getting in blind as you might need to later as it is quite a ways inside the unit.

[booster]

I just got some very, very, very, bad and unbelievable news from Isotherm.

Once you install the ITC, it reprograms the Compressor module so going back to the mechanical thermostat wouldn’t work.

It looks like am going to have to replace the module, which really sucks, big time. I can't believe they would do that kind of thing and not tell you anywhere. When I tested initially, I must have done all the mechanical tests first, I guess.


I sent a message back to them and asked if your SEC would have the same problem in going back.

[@Michael]

Originally Posted by booster

I sent a message back to them and asked if your SEC would have the same problem in going back.

The ITC must have automatically reprogrammed the unit.

FWIW - Secop has software (Tool4Cool) and hardware (LIN/One-wire gateway) that OEM's can use to reprogram the controllers:

https://www.secop.com/solutions/appl...are-tool4cool/

I haven't found any DIY'rs who've done this though.

[booster]

There is no way I am going to let us get held hostage to the ITC with no backup. Isotherm electronics have not had a stellar reputation for reliability going back to when I bought our original frig over 10 years ago. I think their auto control was the one that used a cold plate back then and person I talked to at Isotherm USA mentioned that he generally recommends against it because if you get failure you are stuck waiting for parts as you can't get them many places. Would really be bad on a boat in wherever land, I suppose and that is the biggest part of the business. I think he also knew they were unreliable.


Looks like I will be buying a new module.

[GeorgeRa]

Thank you for the bad news, looks I will be getting just new mechanical thermostat for the current SECOP if there are no faults found (thank you for asking about if SEC is acting like ITS) or just new SECOP with mechanical thermostat.

I sent my temperature chart with summary to Mike Cusare / Technical Support Isotherm Marine Refrigeration, lets see what will be his advice. He offer help couple of weeks ago, during our phone conversation for SECOP/ITS installation.

[avanti]

Originally Posted by booster

Would really be bad on a boat

If I had a boat, I would significantly increase my budget for spares.

[booster]

Originally Posted by GeorgeRa

Thank you for the bad news, looks I will be getting just new mechanical thermostat for the current SECOP if there are no faults found (thank you for asking about if SEC is acting like ITS) or just new SECOP with mechanical thermostat.

I sent my temperature chart with summary to Mike Cusare / Technical Support Isotherm Marine Refrigeration, lets see what will be his advice. He offer help couple of weeks ago, during our phone conversation for SECOP/ITS installation.

You may want to also ask him if you can even go to the mechanical now that the SEC has been on the frig. It may be just like the ITC that way and reprogrammed the module. That is what I asked the contact I had.


I didn't know about the reprogramming, but ask him about that also if you get the chance, as I would probably send my current one in to get done and carry it as a spare.

[GeorgeRa]

Had a long email exchange with Mike from Isotherm. His thought was that SEC is the culprit. His recommendation was to go back to an Isotherm capillary thermostat so with SEC capillary backup is possible, no reprogramming. His preferance was to get an updated SECOP 101N0510 with ITC.

[booster]

Originally Posted by GeorgeRa

Had a long email exchange with Mike from Isotherm. His thought was that SEC is the culprit. His recommendation was to go back to an Isotherm capillary thermostat so with SEC capillary backup is possible, no reprogramming. His preferance was to get an updated SECOP 101N0510 with ITC.

Interesting about the SEC being no program to go back to mechanical, but he recommends a new module with ITC so would have no backup. No way I would do that a have possibility to get stuck, especially when the ITC doesn't even work very well, with large temps swings and uses more energy than the mechanical. All it has going it is having a display and soft start.

[GeorgeRa]

Originally Posted by booster

Interesting about the SEC being no program to go back to mechanical, but he recommends a new module with ITC so would have no backup. No way I would do that a have possibility to get stuck, especially when the ITC doesn't even work very well, with large temps swings and uses more energy than the mechanical. All it has going it is having a display and soft start.

Where did you place the ITC sensor, how far from the icebox? Is it possible that placing temperature sensor closer to cold plate could increase efficiency? Temperature set point would need to be lowered which I think ITC can do.

Two interesting point, see new charts:

1. Tight control of high temperature in the freezer on 5 setpoint.
2. Thermostat set to 5 gives decent control but still too high. I ask Isotherm fellow for spec for the SEC temperature sensor so I could check it, but he didn’t have one.

Tomorrow the fridge is going on the bench.

[booster]

Originally Posted by GeorgeRa

Where did you place the ITC sensor, how far from the icebox? Is it possible that placing temperature sensor closer to cold plate could increase efficiency? Temperature set point would need to be lowered which I think ITC can do.

Two interesting point, see new charts:

1. Tight control of high temperature in the freezer on 5 setpoint.
2. Thermostat set to 5 gives decent control but still too high. I ask Isotherm fellow for spec for the SEC temperature sensor so I could check it, but he didn’t have one.

Tomorrow the fridge is going on the bench.

I put it in the recommended place which even had dimples in the back wall to help find. Just right of center about 4-5" off floor of frig. ITC instructions should give you this is you download them, I think.


I was going to to try to do two things this winter to test. First would have been to make small "ducts" from just below and toward the center from the freezer box down to the sensor to get it cold faster. Probably would have used wiring raceway covers in pvc as I would look for a shallow hat section. It might have needed a couple to get wide enough. The other was going to be moving the sensor around to see what it did in various places. Yes you can set the temp setting. I will go out and get the manual for ITC as I think it gave max setting range.


None of this is going to happen, though, as the lack of ability to go back to the mechanical stat is a disqualifier for the ITC. I have ordered a new module. $219 off ebay from a seller that also has a real supply store business that sells it for the same amount but no shipping and has been is business a long time with stellar reviews. It will be here maybe by the end of the week.

[GeorgeRa]

Originally Posted by booster

I put it in the recommended place which even had dimples in the back wall to help find. Just right of center about 4-5" off floor of frig. ITC instructions should give you this is you download them, I think.


I was going to to try to do two things this winter to test. First would have been to make small "ducts" from just below and toward the center from the freezer box down to the sensor to get it cold faster. Probably would have used wiring raceway covers in pvc as I would look for a shallow hat section. It might have needed a couple to get wide enough. The other was going to be moving the sensor around to see what it did in various places. Yes you can set the temp setting. I will go out and get the manual for ITC as I think it gave max setting range.


None of this is going to happen, though, as the lack of ability to go back to the mechanical stat is a disqualifier for the ITC. I have ordered a new module. $219 off ebay from a seller that also has a real supply store business that sells it for the same amount but no shipping and has been is business a long time with stellar reviews. It will be here maybe by the end of the week.

I verified ITC impacting SECOP controller, this is the reply from Isotherm:
“Unfortunately, you cannot switch between the two, once the module is programed to the ITC it saves the information and would have to be reprogramed.”

Did you gat DC or AC/DC unit?, there are many SECOP sellers on ebay, can you share your source, supplystuf has high rating - Secop 101N0510 $220

Fridge is almost out, last temperature measurements with different SEC thermostat settings. I am convinced compressor works OK. Last change was switching power from DC to AC, after that change temperature went down, I am clueless why, all DC measurement was done on at 13.4VDC.

I just got a decent power supply to bench test the fridge. Saga continues.

[booster]

That is the same vendor I got ours from. It got here yesterday.



What a PITA to try to get in. You read the Isotherm instructions, watch a couple of Utube videos and it looks like cake. Except on our frigs you have move the compressor a bit off the frig to get enough clearance to get the module to unhook and be able to unplug it. One screw on the top of the base plate for the compressor and of course two more on a flange in the back which required removing my fresh air duct and some of the foilboard insulation and then bend the tubing a bit to move out the compressor and mount. I finally got it out late this afternoon and will try to put in the new one tomorrow, and I know plugging it in to the compressor is going to be ugly as there still isn't much room.



Are you still considering putting in the ITC knowing that you are locked in to it so SOL if it fails on the road? If so, you are braver and more trusting than I am. With such minimal positives and plenty of negatives, not for me.

[GeorgeRa]

Sorry you have so much trouble with the Secop controller reinstall. I assume moving compressor requires some tube bending, not good. It looks like I will need to move the compressor a few inches to access Secop>Compressor connector.

I am dragging my feet with the fridge repair focusing on another higher priority project. In the meantime, these SensorPush temperature sensors are giving me real fridge performance data without taking much of my time.
Didn’t make final replacement decision yet. I am certain that my SEC is not good.

It is possible I will be just adding a new capillary thermostat in lieu of SEC.

Still pending:
- Bench test with generic capillary
- Reading Secop codes

I am struggling to understand why my fridge keeps on #6 of the SEC thermostat dial 43.8*F on DC and 42.4*F on AC, should be the same. Could be the Secop issue. My Secop currently provides 24V for the fridge light bulb, should be 12V.

ITC vs capillary decision still pending.

[booster]

The changing of the module didn't need to be as hard as it was, but none of the instructions I found were correct for the limited space of the Isotherm, even the instructions from Isotherm. Add to that the fact that the parts list doesn't show any of the 3 screws or the base plate they go through to hold the compressor in place so I was totally in the dark when I realized the compressor had to be moved to get the module out. The duct and insulation in the way were my own issue as in stock form they wouldn't be in the way.



It looks like your frig also has foilboard on the the back of it, so you would have the same issue there, but no duct to remove.


I also hate to move the tubing to move the compressor out of the way. It just isn't a good idea to do that.


I think that the mechanical thermostat may have a resistor inside it, but not sure about that. I saw in schematic drawings a couple of places. I will try to remember to measure that today to see if these do have one. If no resistor, you could just jump out the 3 thermostat connections on the module to test it. It would run in the slowest speed with no resistance in thermostat line other than the what is in the thermostat. If there is a resistor in the stat, you would need a resistor of that value or higher in the jumper.

[avanti]

Hmmm. Sounds like I should not feel too bad that I never got around to modding my fridge.

[booster]

Originally Posted by avanti

Hmmm. Sounds like I should not feel too bad that I never got around to modding my fridge.

That probably depends on what you were going to do to it


I think you have a Novakool and those probably have decent access to the module if needed compared to the Isotherm. Of course the duct and insulation complicated it but wouldn't have been so bad if what needed to done had been known up front. I am still not positive what I am doing is correct or not.


The whole ITC thing is another story completely and was worried about a failure based on some posts on the boat forums and past electronic units by Isotherm also had issues. I never would have gotten one if I didn't think it could be taken back to the mechanical thermostat. The reprogramming of the module by the ITC is something that never would have crossed my mind. Their past electronic controls like George has could be taken back it appears.

[booster]

I put the module in today. Easier than taking it out but I now knew how it all want together. Hardest part was getting connector plugged into the compressor as it was upside down when held in normal position like all the instructions show and stiff, short wires made it a big torsion spring. Finally turned the module to facing up with terminals and brought the wires and connector out the bottom which somehow made the connector orientation nearly right on except for height. Tight quarters, but did finally get it started enough to push on by rocking it it a bit.


Temp wired it all up, including the speed control, and it ran fine so that was the issue. Pretty silly, but at least it is fixed and a lesson learned.


Not cold yet so might change, but running amps now very similar to old frig, at least on the slowest speeds. On low it is barely above 2 amps right now compared to the closer to 3 amps in ECO mode on the ITC which never went to the actual slowest allowable speed of 2000rpm and ran at 2500rpm whenever it ran.


A little testing to do and then will put it all in place and call it done.

[booster]

I went out today and got all the on frig wiring harnesses taped up, tied back and in place and got most of the insulation in place for the final install in place. I ran a quick test of the wiring once in it's final positions and the connectors on and got the very limited result below


Running amps at 35*F frig temp, freezer/evaporator temp not checked, was at 2.2 amps in the lowest speed based on the battery monitor and subracting the other .2amp loads from the monitor reading. I will get better reading accuracy once I get it all done and with the Wattsup on it so I see only the frig use.



This is nearly identical to what we saw in the old frig, so I would expect we will get the same performance if we have the same freezer temp also by tweaking the ratio of freezer to frig a bit.

[GeorgeRa]

Congratulation, nice to have a new and working fridge. How loud is your thermostat? How do you measure compressor RPM?