ITC 1000 install problem

I just installed an ITC 1000 in an Isotherm Drink 130 dc fridge. The controller reads the correct temp and the compressor is running but the box is not getting down to temp. It is cooling but it’s going really slowly.

Controller is set to 25f. Box only getting to about 43f.

I placed the sensor between the evaporator plate and back wall. It’s a small space. About 1/4 of the way down the evap plate. Is that the best place for it? Should I just keep adjusting the temp lower on the controller even though it doesn’t relate to the interior temp?

I have a wireless digital thermometer on the inside that I am able to read without opening the fridge.

Help! On boat and can’t loose the food in our fridge! Thanks!!

May I know what version of the ITC-1000 did you purchase? Is it 220V/ 110V/ 12V? Is the voltage of the power supply and fridge the same as it?
If you connect the fridge directly to the mains, can it cool quickly to 25F?
This can help us to rule out whether it is the way the fridge works that is causing the problem.

It is a 12vdc model.
Yes the voltage is the same on the power supply and fridge.

Can’t check by switching the fridge back to its previous state at this time. I have to do some dismantling and we are underway (sailboat).

Thanks for getting back to me.

Quick follow up question. Is it correct that the Inkbird runs the compressor at the slowest speed?

ITC-1000 is an on/off controller, it does not control the running speed of the compressor, it only affects the opening time of the compressor.
Not sure if the compressor will turn on at a slower speed when powered on?


I just purchased an ITC-1000F in 12v to act as a digital thermostat. I now have this setup to open/close the 12vdc circuit for my Danfoss BD50F compressor. This is a variable speed compressor and I have the cooling switch port set on the negative side, so that I keep a health 12v+ coming from the main breaker panel.

When I attach the Inkbird, the sensed temp and cut in temp seem to work fine. The compressor is running with over 12v at the compressor main connections. However, the evaporator plate is not frosting over and the refrigerator compartment is not cooling.

When I remove the Inkbird from the circuit and plug the 12vdc leads directly onto the compressor (bypassing the Danfoss thermistor with a shunt as described by Danfoss) the unit cools down quickly to below freezing.

I have tried adding the circuit to the positive side leads and negative side leads; all to no positive effect.


Will the compressor synchronize with the cooling indicator switch of the ITC-1000F when connecting the ITC-1000F?
ITC-1000F 12V is connected to 12V supply voltage and powered by 12V.
If the compressor is required to exceed 12V for full operation, it may be because the 12V output of the ITC-1000F is lower than the compressor’s demand that the compressor cannot complete cooling?


The ITC-1000F is being powered by 12v, the display and the features all seem to work according to the provided instructions. The compressor is at 12.6v when running with the ITC-1000F attached. The Danfoss literature states that a minimum of 10.4v is required and a maximum of 17v. So with the multi-meter everything is running within specification.

Any other recommendations? Could I have a bad Inkbird unit? I have noticed that the results are repeatable, in that the unit does not cool when the ITC-1000F is attached and it does cool with the leads directly attached to the compressor terminals.


If the voltage problem is ruled out, the compressor will not work when connected to the ITC-1000F, but the compressor will turn on automatically when connected directly to the power supply, this could be caused by a wiring error/ setup error/ product problem.
Just a troubleshooting step, just in case, please refer to this wiring diagram and check if the wiring is correct or the wires are loose/broken.

If correct, please check if the cooling indicator light on the ITC-1000F is on? The cooling indicator and cooling output are switched on and off synchronously, if the cooling indicator is not on, this may be a setup problem.
The ITC-1000F is set up on the following principle
When the temperature reaches/ higher than TS+DS, it will turn on the cooler, turn off at TS.
Please make sure the current reading is above TS+DS.

In addition, please make sure that the compressor current is within 10A. The ITC-1000F has a power limit, if the power of the cooling unit exceeds 10A it may damage the ITC-1000F and cause output problems.

If all of the above are OK, perhaps you can contact the seller for a replacement to try.

Thank you. We might be getting somewhere :grinning:
I want to make sure we are communicating correctly, so p

lease let me re-state a couple of points:

  1. In my previous wiring attempts, I did not wire the heater ports into the circuit. Because I’m attempting to run a refrigerator that has no heater or heating device and will not ever have a heating device. If neither of those ports are part of the circuit, will this cause an issue?
  2. When using DC power, the loss of voltage supplied is proportionate to the length of the cable to the device being powered. As such, I need to limit the number of breaks/connections/connectors used on the + side of the circuit. However, this is not true of the - side of the circuit. Therefore using your latest diagram, can I just reverse the polarity of the leads making the two cooling ports of the ITC-1000F a “-” and not a “+”? Please see my enclosed sketch.
  3. If the heater ports must be included in the circuit for proper operation, can I just run both of them to the negative side of the circuit? Again please see my diagram.

Thank you for all your help, and I look forward to any modifications to my sketch to make the ITC-1000F work for my Danfoss Compressor.

If you are not using the heating unit, terminals #5 & #6 do not need to be wired.
Please connect the ‘’+’’ of the power supply to terminal #1 & #7. The ‘’-’’ of the power supply to the ‘’-’’ of the cooler. The “+” of the cooler to terminal #8. The cooling ports of the ITC-1000F cannot be ‘’-’’ & “-”. Maybe you can follow the wiring diagram I posted earlier and do the wiring except for the heating side, does the cooling unit work as expected?