Another AC question: compressor idling/temp switch

Dlc

Dlc

Well-Known Member
Site Donor
Messages
211
Reaction score
210
Location
Austria
Calling out to all AC experts on the forum:

my AC system is freshly refilled and working nicely again, in time for the hot season.

Now I am experimenting with the temp switch, to find the right setting of compressor idling and cold air:
I started with the standard aftermarket temp switch, locating the probe deeply into the evaporator.

This produced very rapid on/off-idling cycles, the evaporator started to blow cold, then the switch went off... then again, you could hear the TXV working, feel cold air... and off again.
Too short cycling.

So i relocated the probe and pulled it a bit back -- this works better now, less rapid on/off, but still too sensitive.

So my questions to the group:

a) what is the common compressor idling cycle, is the temp switch shut off and on rapidly every two minutes the regular and to-be expected behavior?

b) I also thought about experimenting with a digital temp switch, where you can set a shut-off temp and a turn-on-again temp. Which settings would be recommended for this?
Off at 32° F (0° C) - on again at 50 °F (10° C)?

thank you - any comments appreciated!
Dominik
-
 
What happens when you turn the knob all the way to the right?
 
The know all to the right/full cold is the rapid idling....
it gets better when the probe sits a bit further outside, but the behavior still seems somewhat hectic to me
 
What fan speed are you using? My compressor cycles less frequently at max fan speed.
 
I have installed an aftermarket fan with 3 separate speeds. I have been running it at low speed mostly. Will try full speed.

Just did take the car for another ride and did measure air temp directly above the evaporator (put the the temp probe right above the opening in the intermediate piece).
I also used a digital temp switch that I set to go down to 0.1 ° C (32° F). When the compressor kicks in and the TXV opens up, you can see them air temp drop very quickly down to 32°F. I set had the digital switch to come back at 50° F, and that proved to be a cycle of 1-2 mins. It seems that my AC gets very cold very quick.
 
72F is chilly here in S. Florida.

I too had (have) the same issue with the compressor cycling too often and not maintaining a more desired temperature, and this is happening with temperatures of 85-90 plus F. I also tried to reposition the temperature probe with some success, and even swapped probes as we tried several as some allow adjustment on the back of the switch. We used ice water to put the probe in to test.

Stay cool

jjs2800cs
 
  • Like
Reactions: Dlc
jjs2800cs said:
72F is chilly here in S. Florida.

I too had (have) the same issue with the compressor cycling too often and not maintaining a more desired temperature, and this is happening with temperatures of 85-90 plus F. I also tried to reposition the temperature probe with some success, and even swapped probes as we tried several as some allow adjustment on the back of the switch. We used ice water to put the probe in to test.

Stay cool

jjs2800cs
Click to expand...
Have you taken fan speed into account?
 
You must log in or register to reply here.
Back
Top