Something wrong with cooling.

[forestcat]

Hello, my thermo king sb-210 reefer stopped working in august. it showed codes 32 and 26 and 89. i was starting the unit in cool mode and it will shut down in couple of minutes. the codes. outside temperature was 90 Fahrenheit. Yesterday i got a chance to take a look at it. It started fine and was cooling . Outside temp was 50 Fahrenheit. I set unit to cool to 0F. In 30 minutes i have these readings : Discharge temp 0F , TPDF -11 F, Coil 12 F, Suction pressure 24 , Discharge pressure 176 , Etv position 800. Any idea what is wrong with the unit and where do i start?

[Shibhrac]

the 32 and 26 error code is related to refrigeration capacity and when the refrigeration system can not be operated or started (fail to run smoothly) the 89 error code is displayed.going back to you finding today and with comparison to the August cases . assuming the changing factor was the ambient temperature which usually effect the high side part of the refrigeration system. i would suggest inspection to the high side components, such as condenser fan motors or motor driven sensors.

[forestcat]

Thanks, is it possible that the unit is just low on refrigerant? from what i remember discharge pressure was always around 250-300 psi. i have 404a refregirant in the unit.

[IRMechanik]

Thanks, is it possible that the unit is just low on refrigerant? from what i remember discharge pressure was always around 250-300 psi. i have 404a refregirant in the unit.

Check the sightglass in the receiver tank, running in high speed cool the ball should be up.
Discharge pressure does seem low but at 50 ambient it's not too low. 11 degree tpdf is decent but a little low.
Code 89 is ETV circuit. Basically the unit has moved the Electronic throttling valve but it failed to see a corresponding change in the suction pressure. This is usually caused by low refrigerant or a failed ETV. Most often it's low refrigerant but it has to be almost empty to see this code.
Try running a full pretrip. A download would be helpful to see exactly what was going on when it set the codes.

[forestcat]

Thank you very much! I would try to obtain tools for download.