29
UNIT OPERATION WITH A WALL-STAT
Front Panel Display Operation in Wall-Stat Mode
The indoor ambient temperature sensor is disabled. All buttons are disabled with the following exception:
A. Maintenance commands.
B. The user menu for Freeze protection (Display/Enter button for Kuhl+ only units).
C. First Button push to illuminate the back light (display will dim).
Maintenance features are operational. This includes the Check Filter, Lock Panel, M3, M4, M5, and the Service
wrench icon. Under T-stat operation, as a default, the selected operating Mode (Cool, Heat or Fan) will not show on
the front panel. The Service ICON ( ) is displayed if a malfunction is detected.
Cool/Heat/Fan modes and Fan speed operations are controlled by the remote wall thermostat.
The fan speeds can be Low or Max for 4 speed units and Low or High for 3 speed units. (T-stat selected must have
2 speed capabilities)
Thermostat terminals requirements:
Must be single stage heat/cool.
For cooling only units:
C, R, G, Y
.
For cooling with electric heat units:
C, R, G, Y, W
.
For heat pump units:
C, R, G, Y, W, B
.
(See page 68 for RT5 T-Stat wiring diagrams)
During Heat Mode
:
The B terminal must be continuously energized. The W terminal from the T-Stat must have 24 V AC output to call
for heat. The control board decides on whether to turn on the Heat Pump Heat (compressor) or Electric Resistance
Heat. The Y terminal should not have 24 VAC output during Heat Mode.
