Since I bought the Hunter 290 new in 2001, the refrigerator has been problematic, primarily due to the design and quality of the thermostat that Adler-Barbour uses to control the temperature of the box. The analog thermostat uses sensor that monitors the temperature of the evaporator, rather than the temperature of the box, as a home refrigerator does. The relationship between evaporator temperature and box temperature, while correlated, is not entirely predictable, and needs trial and error to get the box temperature right. Furthermore, when ice or frost builds up between the sensor and the coils, the relationship changes, and the sensor reads a temperature that is higher than the coil, causing the refrigerator to run constantly and driving the box to a lower than desired temperature, often freezing.
Short of a slow leak that developed a few years ago, the compressor works very well. We have been through three thermostats in the last year, and the last one was installed this summer ($160 parts and labor), and is now acting erratically.
I decided to take care of this problem once and for all by installing a digital controller with a thermocouple that measures refrigerator temperature directly. I bought a digital controller for $69 from Omega Engineering (model #CN4316-R1-R2) and a K-type thermocouple (model #HSTC-TT-K-20S-120) for $39. The controller needs to be configured, but it is a simple task for which I have detailed the parameters for below. I disconnected the analog thermostat from the compressor and connected them to terminals 6 & 7 on the controller. I applied power to terminals 1 & 2 on the controller, and connected the sensor to terminals 8 & 9. (red goes to 8, yellow goes to 9). I had to drill a small hole through the side of the refrigerator to get the sensor in. I put the sensor under a tray I keep in the ice box. You can put it anywhere you like, but if you leave it hanging out in the breeze, it will tend to cycle the compressor more than if you bury it in with your refrigerated goods. I cut a small hole in the front of the cabinet where the compressor is to mount the controller, configured it as shown below, and the ice box works perfectly. It cycles about 3 or 4 times an hour, but is holding the temperature at 35 - 39 degrees.
Configuration:
Temperature setpoint = 35
CtrL = onoF
Srun = run
Act = dr
Ctl = 300 (this will prevent your compressor from cycling more than once than every 300 seconds)
CHYS = 4 (this means that the temperature will not be allowed to vary by more than 4 degrees above the set point)
InP = 0
dPt = 0.0
FILt = 40
Fru = 60F
Opt = rELy
Leave all other parameters at their default.
Short of a slow leak that developed a few years ago, the compressor works very well. We have been through three thermostats in the last year, and the last one was installed this summer ($160 parts and labor), and is now acting erratically.
I decided to take care of this problem once and for all by installing a digital controller with a thermocouple that measures refrigerator temperature directly. I bought a digital controller for $69 from Omega Engineering (model #CN4316-R1-R2) and a K-type thermocouple (model #HSTC-TT-K-20S-120) for $39. The controller needs to be configured, but it is a simple task for which I have detailed the parameters for below. I disconnected the analog thermostat from the compressor and connected them to terminals 6 & 7 on the controller. I applied power to terminals 1 & 2 on the controller, and connected the sensor to terminals 8 & 9. (red goes to 8, yellow goes to 9). I had to drill a small hole through the side of the refrigerator to get the sensor in. I put the sensor under a tray I keep in the ice box. You can put it anywhere you like, but if you leave it hanging out in the breeze, it will tend to cycle the compressor more than if you bury it in with your refrigerated goods. I cut a small hole in the front of the cabinet where the compressor is to mount the controller, configured it as shown below, and the ice box works perfectly. It cycles about 3 or 4 times an hour, but is holding the temperature at 35 - 39 degrees.
Configuration:
Temperature setpoint = 35
CtrL = onoF
Srun = run
Act = dr
Ctl = 300 (this will prevent your compressor from cycling more than once than every 300 seconds)
CHYS = 4 (this means that the temperature will not be allowed to vary by more than 4 degrees above the set point)
InP = 0
dPt = 0.0
FILt = 40
Fru = 60F
Opt = rELy
Leave all other parameters at their default.
Guess they just don't make 'em the way they used to...