8
802961 Rev. 00
WALL THERMOSTAT OPERATION
Heat
Sets the unit into heating mode.
Initiates heating when room
temperature falls below set point.
Off
Disables heating and cooling modes,
but allows control of fan.
Cool
Sets the unit into cooling mode.
Initiates cooling when room
temperature rises above set point.
Auto
(not shown)
Found on automatic changeover
thermostats only. Allows the
thermostat to decide whether it should
be in the heating or cooling mode.
Usually a 4 F
q
differential or
“deadband” will exist between
heating and cooling set points to
prevent inadvertent rapid switching
between modes.
Temperature
Setting
Establishes the “set point”, or desired
room temperature.
Fan On
Synonymous with “Fan Continuous”.
Fan will continue to run after the
heating and cooling function has
cycled off. Fan will continue to run
even when mode switch is in Off
position.
Fan Auto
Synonymous with “Fan Intermittent”.
Fan will cycle on and off with the
heating cycle or cooling cycle, and
will not operate between cycles.
ADDITIONAL FEATURES:
Some additional features of the Electronic Control units are
as follows:
Room Freeze Protection
This feature is enabled when the unit is shipped from the
factory. The feature can be disabled by qualified service
personnel. If power is available to the unit, and regardless of
whether it is turned ON or OFF, the unit will automatically
supply heat to the room with the fan running at low fan
speed if the room temperature falls to 55°F (13ºC). The heat
will turn off when the room temperature reaches 60°F
(16ºC). For the feature to work, the unit must be configured
with a heat source, whether it be electric heater or hydronic
(hot water would need to be standing by). The feature is
enabled whether the unit is configured for keypad or remote
thermostat.
Compressor Short-Cycle Protection
If the electronic control shuts the compressor down for any
reason, a 3 minute time delay will elapse before the
compressor is allowed to re-start. This prevents compressor
overload during re-start due to unequal system refrigerant
pressures.
Indoor Coil Freeze Protection
Control of frost on the evaporator coil due to low indoor
loads, or cold outdoor ambient temperatures, is provided.
The protection remains active when the unit is OFF, for
either keypad or remote thermostat application, as long as
the unit is plugged in, power is available, and a heat source
is configured in the unit and is working.
Low Outdoor Temperature Lock-out
If the outdoor temperature is too low for proper compressor
operation, cooling operation will be suspended.
Indoor Temperature Limiting (Keypad Control Only)
Using the keypad control and display, high and low
temperature limits can be established to prevent the user
from entering set point temperatures colder or warmer than
what the property manager or hotel operator may desire. The
temperature limit choices are as follows:
Configuration Code
Low Limit °F
(ºC)
High Limit °F
(ºC)
R1
63 (17)
86 (30)
R2
65 (18)
86 (30)
R3
65 (18)
90 (32)
R4
67 (19)
88 (31)
R5
67 (19)
92 (33)
R6
69 (20)
90 (32)
R7
69 (20)
72 (22)
The procedure to set the limits is as follows:
Depress the On/Off key, the °F/°C key, and the Warmer key
simultaneously for 5 seconds to enter the limit setup mode.
The Warmer and Cooler keys will scroll through the R-
values indicated in the above table. Once the desired R-value
has been obtained on the display, press the On/Off key to
accept the change, and then press it again to effect the
change and restore the normal display.
ELECTROMECHANICAL DIAL CONTROLS
Room temperature is controlled on both heating and cooling
by the temperature control knob. Clockwise rotation
decreases the temperature in the room. Counter-clockwise
rotation decreases the temperature in the room.
Rotate the “Temperature” dial a small amount at a time in
the direction that you wish the temperature to go. Moving
the dial more than ½” at a time may over-compensate
leading to an extreme hot or cold situation. Once a
