21
PTAC-PRC001-EN
Mechanical
Specifications
Unit Controls
The unit controls will be full solid-state
and accessible from the top. The
standard unit mounted controls will
include two rotary (switch) knobs
controlling unit operational and
temperature mode. The unit operational
switch includes:
• Off position.
• Fan only — unit operates on low fan
speed.
• Low cool — unit operates on low fan
speed to circulate air for cooling.
• High cool — unit operates on high fan
speed to circulate air for cooling.
• Low heat — unit operates on low fan
speed to circulate air for heating.
• High heat — unit operates on high fan
speed to circulate air for heating.
Temperature Switch
The temperature switch is controlled by
turning the knob clockwise for a cooler
room temperature; turning it
counterclockwise will provide a warmer
room temperature. Adjusting the
thermostat to the mid setting (vertical)
will set the room temperature at
approximately 75°F.
Remote Control Operation
To operate units with remote
thermostats, the Standard/Remote unit
mounted switch must be set to the
remote position. When in the remote
position, the unit will only respond to the
wall-mounted thermostat inputs. Unit
will operate on low or high fan.
Remote Thermostat/Sensor Terminals
These terminals provide control inputs
for a remote thermostat or sensor.
Front Desk Control Terminals
These terminals provide control inputs
for a front desk switch.
Load Shedding Terminals
The LS/IN terminals will provide a
connection for a switch that can be
added to close the circuit and lockout the
compressor and electric heat when the
power company or energy management
system is trying to reduce its load for a
specific time.
On Board Diagnostics
An LED light will flash a code displaying
8 conditions: Control OK, 24 Vac Fuse
Blown, ICT (Indoor Coil Temperature)
Probe Failure, Mode Switch Failure,
Potentiometer Failure, Bad Thermostat
Input Failure, Bad Communications in
Slave Mode, and IAT (Indoor Air
Temperature) Failure. A spare 500 MA
fuse has been provided on the board.
Temperature Limiter
The temperature limiting feature can
reduce energy costs by controlling the
maximum temperature in heating and
the minimum temperature in cooling.
Room Freeze Protection
Freeze protection is built into all units
and will activate the electric resistance
heater (when it senses a temperature of
40°F room temperature) to maintain an
above freezing temperature at the
sensor.
Fan Cycle Switch
The fan cycle switch sets the operational
mode of the fan. In the ON position, the
fan will run continuously whenever the
unit is in the heat or cool position. In the
AUTO position, the fan will cycle on and
off with the compressor or electric heater
when the unit is in the cool or heat
mode.
Automatic Emergency Heat Staged
Thermostat
On every unit mounted control heat
pump, electric heat engages
automatically if the sealed system or
compressor fails.
Compressor Time Delay
The compressor will not try to restart
once running or until approximately
three minutes have elapsed after
shutdown.
