Isotherm Cruise 85 caput.

[GeorgeRa]

Originally Posted by avanti

Do you know about the LED diagnostic light that you can install between the + and the D terminals? It will flash error codes when something is wrong.

Thank you Pete, I didn’t know. I read something about reading codes for which a special device was necessary, I am glad that LED can be used. I found the schematic and LED readout info:

“These error codes can also be read out via an Error LED, connected between + and D/I. See Chapter 3 on page 5.”

“LED (option b) A light emitting diode (LED) (6) can be connected between the terminals + and D/I. It will be driven with a regulated current of 10mA. In case the electronic unit records an operational error, the diode will flash a number of times. The number of flashes depends on what kind of operational error was recorded. Each flash will last ¼ second. After the actual number of flashes there will be a delay with no flashes, so that the sequence for each error recording is repeated every 4 seconds. Operational errors Error code or LED flashes Error type Can be read out in the software TOOL4COOL®

6 Thermostat failure (If the NTC thermistor is short-circuit or has no connection).

5 Thermal cut-out of electronic unit (If the refrigeration system has been too heavily loaded, or if the ambient temperature is high, the electronic unit will run too hot).

4 Minimum motor speed error (If the refrigeration system is too heavily loaded, the motor cannot maintain minimum speed at approximately 1,850 rpm).

3 Motor start error (The rotor is blocked or the differential pressure in the refrigeration system is too high (>5 bar)).

2 Too many start attempts or fan over current (Too many compressor or fan starts in short time or fan current higher than 0.5Aavg).

1 Battery protection cut-out (The voltage is outside the cut-out setting)"

[GeorgeRa]

Question to ITC installers with some experience (Booster), if I choose a new 101N0510 controller with ITC my plan is to mount it into the front panel to the galley. The galley is built from 8020 1.5” frame. If I would use flush mount by shaving flanges down to 54mm it should fit, I think. Are there any other issues with this my mounting concept?

[booster]

Originally Posted by GeorgeRa

Question to ITC installers with some experience (Booster), if I choose a new 101N0510 controller with ITC my plan is to mount it into the front panel to the galley. The galley is built from 8020 1.5” frame. If I would use flush mount by shaving flanges down to 54mm it should fit, I think. Are there any other issues with this my mounting concept?

You are referring the flanges on the box that holds the snap in circuit board assembly and cover, I assume. The kit came with two boxes, one for flush mount and one for surface mount, but I didn't look very closely at the surface mount one because I didn't have a place for it that way. I do think what you are saying should work OK, depending on how wide that flush mount box is. My guess is that the flanges are all that changes.


The final assembly kind of snaps together and it all is very, very tight so high level of risk for damaging things if you have to take it apart again. This is especially true for the circuit board/display that snaps in last. I filed a bit off the plastic hooks to make it easier to remove from the cover. It was lucky that I had test fit it one the bench into the cover without the cover on the box so I could release the hooks from the back of the cover or I don't know if I could have gotten it apart without damaging the front display bezel which is where you pry.


As I mentioned in my testing writeup, it is way too bright of a display so an area that doesn't shine directly on sleeping is a good idea, at least for us. I need to find a small piece of window tint to put on it to calm it down, I think, even facing the other way on the countertop wall.


For reference, I am in the process of rewiring ours to put in a manual compressor speed control in the mechanical thermostat setup and finally found the factory speed resistor so I could measure the resistance. It was 466 ohms on the Fluke. I think it would be a bit under 3000 rpm IIRC the speed chart right. The specs don't say what speed they run the various models at, but the amps said it was considerably higher than the 2000 rpm minimum. I also am adding a master on/off switch and indicator LED by the front of the frig so we can get the always powered interior light to shut off when the frig is off and door open a bit to ventilate. It will kill all power in both modes. It is taking me longer to do the rewire than I thought it would as I decided to clean up the stuff I originally did to get the switchable modes between ITC and mechanical thermostat control. I was on limited time to get it all done and tested as the old frig failed on our first spring trip and thought I would choose be going mechanical only based on the testing, plus the ITC used some clunky adapter plug in connectors that made for a huge harness. I cut out all the messy, big, sections and soldered in new wires and now the harness is about half the size in that area.



I did run a quick start up rate for the two modes before I took it all out to see if the compressor has a built in soft start, as I had read that it did a couple of places that weren't official Secop sites. The mechanical thermostat mode appeared to get to running amps in about 1/2 the time of the ITC so it appears it was not seeing a soft start like the ITC has built into it. The softstart is probably the biggest benefit of the ITC as the adjustable speed mechanical thermostat tested as more efficient on power use.



I ran a third wire back from the center connection for the mechanical thermostat that is not used for the ITC so I could move the ITC only capacitor to the ITC control disconnect connector to get it out of the circuit when in mechanical thermostat mode. I hope moving it further away from the control unit won't be an issue as a lot of cap filters, which I think this is, are desired as close to the the electronics as possible. The wiring in each mode will now be exactly to the diagrams for each version of frig, except for that distance. The mode swapping connectors are on the rear of the frig, accessible through the lower vent removable panel.

[GeorgeRa]

Thank you for answers!

Following Pete’s recommendation, I am going to test for existing faults but need to remove the fridge to access D terminal. Found 1kOhm resistor and LED. I can access the SEC by removing the stove but there is no D connection.
Yesterday the fridge stopped working on DC power. I got it to work again by switching to AC resulting in rapid cooling bonding my wet fingers into the ice box in a minute. Today fridge stopped working on AC, slightly heated temperature sensor forced compressor to action. In all cases SEC was set to max. I am still holding to my wish that fridge will not have to be replaced, when the compressor works it works well.

My primary reason to eliminate capillary thermostat was its loud clicking, during night it was intolerable. After a few months of SEC success, I cut capillary of the original thermostat, in the hindsight I should have kept it.

[GeorgeRa]

I decided to better understand failures and since yesterday measured the fridge temperatures every minute. Experiment details.
- Battery voltage 13.4V, Magnum charger on
- Garage temperature stable 65F
- Sensor placed inside freezer compartment
- Thermostat set to maximum

Results:
- 8PM 11/22 – 12PM 11/23 AC powered, thermostat turned on, cycled -11.9 – 30.5F about every 1.5 hr.
- 12:00PM AC CB turned off, DC CB turned on, fridge died.
- 12:30PM DC stayed on, fridge thermostat cycled on and off, fridge cycled -10.1 – 31.3F about every 1.5 hr.

Conclusions:
Compressor works
Temperatures range is slightly different under AC and DC power
Temperatures range is over 40F, huge. perhaps capillary is better
Either SEC or SECOP controllers don’t work if switched on by CBs.

Tomorrow I will be turning fridge by CBs or thermostat on DC at no charging voltage. I don’t think I had this switching by CB conditions earlier so something has changed.

[booster]

Originally Posted by GeorgeRa

I decided to better understand failures and since yesterday measured the fridge temperatures every minute. Experiment details.
- Battery voltage 13.4V, Magnum charger on
- Garage temperature stable 65F
- Sensor placed inside freezer compartment
- Thermostat set to maximum

Results:
- 8PM 11/22 – 12PM 11/23 AC powered, thermostat turned on, cycled -11.9 – 30.5F about every 1.5 hr.
- 12:00PM AC CB turned off, DC CB turned on, fridge died.
- 12:30PM DC stayed on, fridge thermostat cycled on and off, fridge cycled -10.1 – 31.3F about every 1.5 hr.

Conclusions:
Compressor works
Temperatures range is slightly different under AC and DC power
Temperatures range is over 40F, huge. perhaps capillary is better
Either SEC or SECOP controllers don’t work if switched on by CBs.

Tomorrow I will be turning fridge by CBs or thermostat on DC at no charging voltage. I don’t think I had this switching by CB conditions earlier so something has changed.

If I am reading the results right, you got a 40*F differential, which is truly huge. Almost like it is in storage/super cool mode all the time but even much larger swing that that, which usually limits at 32*F frig temp.


What may be more likely going on is that you have the sensor, which if it is like the ITC is an electronic one, in the freezer and it is normally in the frig area which has a big temp delay when compared to the freezer. The freezer maybe stays cold enough to keep it shut off for a long time before it starts again.



Another possibility might be that the thermostat on max may just run it to the cold limit setting it probably has before shutting off and then it doesn't come back on again until it gets to what the setpoint really is to turn on again.


Very odd though.



You have an AC-DC frig?


The mechanical thermostats are made to be in the freezer or on the evaporator somewhere. They have a wide hysteresis so really no choice in the matter because of that big swing. The temp response difference of the freezer is much faster than the frig so the "smoothing" of the cooling to the frig gives much smaller temp swings than if the mechanical thermostat was in the frig. You can move the capillary bulb around and tweak the amount of delay and thus temp difference between the frig and freezer. On our old frig, I generally had the bulb on the outside, top, in near the back of the freezer box. Basically just on the other side of freezer box from where it was inside the box. This gave a warmer freezer and cooler frig and increased efficiency by a measurable amount, IIRC maybe 10% or more. You can also get about the same effect by just removing the drip tray so the evaporator sends more cold air to the frig and freezer warms up faster.


Sounds like you may need a new controller, though, which you already know. There is an ebay seller that is at $219 and appears to be a real dealer also with their own website and been in business a long time.

[GeorgeRa]

Originally Posted by booster

If I am reading the results right, you got a 40*F differential, which is truly huge. Almost like it is in storage/super cool mode all the time but even much larger swing that that, which usually limits at 32*F frig temp.
What may be more likely going on is that you have the sensor, which if it is like the ITC is an electronic one, in the freezer and it is normally in the frig area which has a big temp delay when compared to the freezer. The freezer maybe stays cold enough to keep it shut off for a long time before it starts again.

I have SEC (Smart Energy Controller) with temperature sensor located in lower right side – see the picture. This thermostat sensor is lagging actual temperature form the cold plate resulting with large swing. Thermostat set to max - #6 with voltage above 13.2V triggers storage mode, perhaps this is causing some issues.

Originally Posted by booster

Another possibility might be that the thermostat on max may just run it to the cold limit setting it probably has before shutting off and then it doesn't come back on again until it gets to what the setpoint really is to turn on again.
Very odd though.

I am getting second temperature probe - SensorPush today and plan to place it next to SEC sensor to compare temperature cycling. If this swing is due to time delay between temperature on the cold plate and SEC sensor a capillary thermostat could solve it. I don’t like my icebox temperature coming near 32F.

Originally Posted by booster

You have an AC-DC frig?

Yes, it is Secop controller 101N0500 which is AC/DC. Newer AC/DC one is 101N0510.

Originally Posted by booster

The mechanical thermostats are made to be in the freezer or on the evaporator somewhere. They have a wide hysteresis so really no choice in the matter because of that big swing. The temp response difference of the freezer is much faster than the frig so the "smoothing" of the cooling to the frig gives much smaller temp swings than if the mechanical thermostat was in the frig. You can move the capillary bulb around and tweak the amount of delay and thus temp difference between the frig and freezer. On our old frig, I generally had the bulb on the outside, top, in near the back of the freezer box. Basically just on the other side of freezer box from where it was inside the box. This gave a warmer freezer and cooler frig and increased efficiency by a measurable amount, IIRC maybe 10% or more. You can also get about the same effect by just removing the drip tray so the evaporator sends more cold air to the frig and freezer warms up faster.
Sounds like you may need a new controller, though, which you already know. There is an ebay seller that is at $219 and appears to be a real dealer also with their own website and been in business a long time.

It seems as I have 3 issues:
1. Large temperature swings – could be time delay between electronic sensor and cold plate temperature. Second SensorPush experiment should tell if it is true.

2. Fridge stops working after power is reconnected. Can be turn on again with SEC thermostat power switch. It seems as an SEC issue.

3. Overnight failure, swing from -15.4 to 41.7F, that is 57.1F swing see the new picture.

I am glad I measured actual temperatures and can see that either SEC or Secop or both devices are not working properly.

Isotherm-parts.com folks sell a kit of Secop 101N0510 with ITC for $375 or Secop 101N0510 with capillary thermostat could be better option.

[GeorgeRa]

I didnt touch the van, garage temperature still 65F. Saga continues....

[SteveJ]

George, would something this simple work for you? I used one on a propane fridge to interrupt the 12 volt power supply to the entire fridge for temp control. It had nice tight temperature control. Ten amp relay rating. Perhaps this could be used to eliminate the problematic controller? Power consumption was quite low.

https://amazon.com/Inkbird-Temperatu...ROL_THERMOSTAT

[GeorgeRa]

Originally Posted by SteveJ

George, would something this simple work for you? I used one on a propane fridge to interrupt the 12 volt power supply to the entire fridge for temp control. It had nice tight temperature control. Ten amp relay rating. Perhaps this could be used to eliminate the problematic controller? Power consumption was quite low.

https://amazon.com/Inkbird-Temperatu...ROL_THERMOSTAT

Thank you, I am still getting more data from 2 sensors, based on the current data it looks like either SEC or SECOP or both are not good. Inkbird could be helpfull if SECOP works. I am questinung myself if a capillary with sensor on cold plate is not better than an electronic thermostat with sensors in refrigerator compartment. Perhaps Booster's soft start and capillary is the best option. Next week I will remove the fridge to get faults readout from the SECOP.

[booster]

Originally Posted by GeorgeRa

Thank you, I am still getting more data from 2 sensors, based on the current data it looks like either SEC or SECOP or both are not good. Inkbird could be helpfull if SECOP works. I am questinung myself if a capillary with sensor on cold plate is not better than an electronic thermostat with sensors in refrigerator compartment. Perhaps Booster's soft start and capillary is the best option. Next week I will remove the fridge to get faults readout from the SECOP.

The soft start would great, let me know if you find one. Might be tough as it will have interface with controller, I think. The built in one one the ISC says it starts on the lowest speed, and that is what we ran probably 98% of the time on the old frig and mechanical thermostat so I still am contemplating getting rid of the ITC again (wishy and washy on that).

[GeorgeRa]

Originally Posted by booster

The soft start would great, let me know if you find one. Might be tough as it will have interface with controller, I think. The built in one one the ISC says it starts on the lowest speed, and that is what we ran probably 98% of the time on the old frig and mechanical thermostat so I still am contemplating getting rid of the ITC again (wishy and washy on that).

I reread your previous post to be clear about the soft start. So either SEC or ITC are the only options. I am observing some strange behavior every few hours, have to put the data from 2 sensors together in synch.

[GeorgeRa]

I measured freezer and refrigerator temperatures over a few days. Conclusions:

1. On SEC thermostat maximum setting refrigerator temperature range would be almost sufficient 41.4*F to 38.8*F except random spikes every few hours
2. On SEC thermostat setting #4 refrigerator temperature range is reasonably stable but way too high 46.4*F to 50.4*F
3. Compressor has cooling capacity to reduce the temperature down to -15.6*F tells me that it is likely OK
4. Random spikes with thermostat set on max point to SEC failure

Next week:
1. I will try to see if there are registered failure codes on SECOP, fridge needs to be removed
2. Test fridge operation with capillary thermostat

[booster]

Originally Posted by GeorgeRa

I measured freezer and refrigerator temperatures over a few days. Conclusions:

1. On SEC thermostat maximum setting refrigerator temperature range would be almost sufficient 41.4*F to 38.8*F except random spikes every few hours
2. On SEC thermostat setting #4 refrigerator temperature range is reasonably stable but way too high 46.4*F to 50.4*F
3. Compressor has cooling capacity to reduce the temperature down to -15.6*F tells me that it is likely OK
4. Random spikes with thermostat set on max point to SEC failure

Next week:
1. I will try to see if there are registered failure codes on SECOP, fridge needs to be removed
2. Test fridge operation with capillary thermostat

Sure sounds like that is what it is. Maybe just the temp sensor though.


Did you leave the little capillary bulb mounting bracket in the frig, so mounting easy now?

[GeorgeRa]

Originally Posted by booster

Sure sounds like that is what it is. Maybe just the temp sensor though.


Did you leave the little capillary bulb mounting bracket in the frig, so mounting easy now?

Temperature sensor could be incorrect, but it is just a simple thermistor I assume.

I never removed the bulb, just cut the capillary once I knew that the SEC was working OK, it was a mistake, should have kept it as back-up.

I think I need to lower the freezer to access the bulb mounting bracket.

[GeorgeRa]

Originally Posted by booster

...................
Did you leave the little capillary bulb mounting bracket in the frig, so mounting easy now?

Is this the bracket you are refering to?, I copy this from SEC installation video but I don't have it there. Could be on top of the freezer.

[booster]

Originally Posted by GeorgeRa

Is this the bracket you are refering to?, I copy this from SEC installation video but I don't have it there. Could be on top of the freezer.

I think the pic is of the switch end control of the thermostat, I think, on the right side above the little shelf, but the light.



On our old Cruise 85 the sensor bulb mounted inside freezer compartment with two screws you can get to with a stubby phillips screwdriver of phillips bit in a hex bit holding ratchet (neat tool to have). I was just little rectangular plate with a stamped in recess for the bulb to fit into and two screw holes. The plate holds the bulb against the freezer box top at the rear. You might have to take out the two screws in the upper edge front of the freezer box and pull it down a bit and out a bit. Ours located the rear on a couple of moulded in areas that you have to clear before it will go down. The hardest part will probably be fishing the bulb in to the freezer again. You may want to tie a string or wire onto the old one and pull it out from the outside, if you left enough tube on it, so you can use the string to pull in the replacement.

[booster]

Originally Posted by GeorgeRa

Is this the bracket you are refering to?, I copy this from SEC installation video but I don't have it there. Could be on top of the freezer.

I think the pic is of the switch end control of the thermostat. on the right side above the little shelf, by the light.



On our old Cruise 85 the sensor bulb mounted inside freezer compartment with two screws you can get to with a stubby phillips screwdriver of phillips bit in a hex bit holding ratchet (neat tool to have). I was just little rectangular plate with a stamped in recess for the bulb to fit into and two screw holes. The plate holds the bulb against the freezer box top at the rear. You might have to take out the two screws in the upper edge front of the freezer box and pull it down a bit and out a bit. Ours located the rear on a couple of moulded in areas that you have to clear before it will go down. The hardest part will probably be fishing the bulb in to the freezer again. You may want to tie a string or wire onto the old one and pull it out from the outside, if you left enough tube on it, so you can use the string to pull in the replacement.


I will go out and look at the new frig and see if it is the same way.

[booster]

Sorry George, I lied to you.


The sensor bulb location is correct, but in stock form the screws come in from the top the box and are very hard to get at and turn. I tiny vise grip works well, IIRC. There are extruded, tapped holes in the plate that holds the sensor. I remember what I really did once I saw it.



When I put the replacement in back then, about 2-3 years after we got the frig, changed it a bit to make it easier if there was a next time.


I epoxied the screws in place in the top of the box and drilled out the extruded threads and used nuts and lock washers on the inside, basically remov the extruded area. I then put on the plate and tube over the screws and put on the nuts and washers. Easy to do in the future.

[GeorgeRa]

Originally Posted by booster

Sorry George, I lied to you.


The sensor bulb location is correct, but in stock form the screws come in from the top the box and are very hard to get at and turn. I tiny vise grip works well, IIRC. There are extruded, tapped holes in the plate that holds the sensor. I remember what I really did once I saw it.



When I put the replacement in back then, about 2-3 years after we got the frig, changed it a bit to make it easier if there was a next time.


I epoxied the screws in place in the top of the box and drilled out the extruded threads and used nuts and lock washers on the inside, basically remov the extruded area. I then put on the plate and tube over the screws and put on the nuts and washers. Easy to do in the future.

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

https://www.youtube.com/watch?v=MeP7X1K3v5c

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