Any help on this is much appreciated. I've tried everything I can, even calling the manufacturer for their PID settings and gotten no where on this. I took a Tenney TJR thermal chamber, removed the old Watlow controller and replaced it with a new Watlow F4T. The heating cycle practically took care of itself but the cooling cycle has been very difficult. It has cascaded compressors. The hi stage turns on, runs for about 15 secs and then the lo stage clicks on. I've set the compressors to be on for at least 30 seconds and off for at least 15 secs to avoid burning out the compressors. The problem is the temperature plummets a few degrees even with the compressors only on for about 40 secs(the graph is C degrees vs time). The profiles only asking for about a 0.5 C drop per a minute so the compressor turns on the heaters to battle the temperature drop. This results in a very jagged cooling profile that can not be the best this chamber can do. Am I misunderstanding something about how the compressors should be controlled? Any tips?
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