MovinCool CM12 Service Manual - Manual (Page 24)

Operation Section
24
5.3 Operation
(1) Basic operation
• When a Y signal is input, the 52CM relay located on the relay board comes ON, and the
compressor operates.
• When a G signal is input, both the 52ID relay and the RX (auxiliary relay) come ON, and the
evaporator and condenser fans operate. However, when the G signal is OFF, both the 52CM
and 52ID relays go OFF, stopping the compressor as well as the fans.
(2) Evaporator fan speed control
• With a G signal on, the fan will start at high speed. When a G1 signal is input, relay 52ID will
become active and fan speed changes from high to low.
(3) Condenser fan speed control (Air Volume Control)
• Condenser fan air volume is controlled by the
ODS (condenser inlet air thermistor).
• When condenser inlet air temperature is
approx. 77 °F (25 °C) or greater...
Condenser fan speed switches to high.
• When condenser inlet air temperature is
approx. 73 °F (23 °C) or less...
Condenser fan speed switches to low.
< NOTE >
However, when the 52ID relay is ON and the ODS temperature is 73 °F (23 °C) or less, the
condenser fan will switch to low speed after running in high speed for 5 seconds.
(4) Anti-frost control
• Anti-frost controls turns the 52CM relay on in accordance with the Freeze Protection Thermistor
(CTS) temperature in order to turn the compressor on and off to prevent a decrease in cooling
performance resulting from a buildup of frost on the evaporator.
• Compressor off conditions: Freeze protection thermistor (CTS) temperature  30 °F (-1 °C)
• Compressor on (recovery) conditions: CTS temperature  50 °F (10 °C) and continuous anti-
frost control for 15 minutes.
ILL00643-00
(Low)
(High)
Condenser Inlet
Air Temperature
Condenser Fan
73°F
(23°C)
77°F
(25°C)