OPERATING CHARACTERISTICS
When a dehumidifier begins its run cycle, a partial frosting of the evaporator can be ob- served. This temporary frosting is limited by the operating conditions of the unit. In all cases, the frost should completely disappear within 10 to 15 minutes.
In cool dry conditions, (65°F or lower tempera- tures, and relative humidity of 60% or less), the evaporator may become completely coated with frost or ice. Under these conditions, the evaporator temperature is reduced to below freezing (32°F) because of inadequate heat load, and it is possible that no moisture will be collected from the air. Mechanical control dehumidifiers without a deicer thermostat are not designed to operate under these condi- tions, and the customer should be advised to discontinue use until proper ambient conditions are present.
TYPICAL OPERATION
The control panel (see below) provides the customer with control over the speed of the fan, (when this feature is offered), and adjustment of the amount of moisture in the air. An indica- tor light also provides information on the water level in the bucket, and whether the bucket is properly installed in the unit.
AB
A. Light glows, indicating the bucket is full or is not in correct position. B. Adjusts amount of moisture removed from room.
A
LOW TEMPERATURE OPERATION
Mechanical control models without a deicer thermostat, i.e. AD25BSS, must not be oper- ated below 65°F. Mechanical control models with a deicer thermostat, i.e. AD35DSS, may be operated as low as 55°F.
Electronic control models, i.e. AD35USS, monitor the temperature of the evaporator us- ing a thermistor and may be operated as low as 38°F.
When the thermistor reaches 30°F, the control begins timing. After 10 minutes at or below 30°F, the compressor is turned off. The fan continues to run for a period of 10 minutes before the compressor is restarted. This low temperature operation will continue until the thermistor reaches 40°F for 20 minutes.
ELECTRONIC CONTROL SENSORS
•The humidistat is an electronic version of the mechanical humidistat. It monitors the relative humidity of the room air.
•The thermistor is a device that changes re- sistance as the temperature changes. The electronic control monitors the resistance and operates the compressor and fan motor accordingly.
DEFECTIVE SENSOR DEFAULT
If either the thermistor or the humidistat fails on electronic control models, the control will operate in the following manner.
•The compressor cycles on for 25 minutes and off for 10 minutes.
•The fan operates continuously at the set speed or High if set to Auto mode.
CB
A.Light glows, indicating the bucket is full or is not in correct position.
B.Adjusts amount of moisture removed from room.
C.Selects fan speed.
