Digital Control Operation - Friedrich PTAC series Service Manual

DIGITAL CONTROL OPERATION

Temperature Display
The Friedrich digital PTAC is shipped from the factory
to display the "Set Point" (desired room temperature) on the
LED readout.
The unit can be configured to display the room temperature
by simultaneously pressing the 'Cool' and 'High Fan' buttons
for three seconds. The display will show an 'R' for one second
to acknowledge the change. The unit will then display the "Set
Point" whenever the Temperature Up
Down buttons are pressed, then switch back to display
actual room temperature.
To revert back to the factory setting displaying the "Set Point"
only, press the 'Cool' and 'High Fan' buttons simultaneously
for three seconds. The unit will display an 'S' for one second
to acknowledge the change.
°F vs. °C Display
The unit is factory configured to display all temperatures in
degrees Fahrenheit (°F). To switch to degrees Celsius press
the 'Fan Only' and 'Low Fan' buttons simultaneously for three
seconds. The display will show a 'C' as acknowledgement of
the change.
To revert back to degrees Fahrenheit press the 'Fan Only'
and 'Low Fan' buttons simultaneously for three seconds.
The display will show an 'F' as acknowledgement of the
change.
Cooling Mode
Pressing the 'Cool' button while the unit is in any mode,
including off, will put the unit into cooling mode. Adjust the
temperature readout to the desired room temperature and
the unit will cycle the compressor on and off to maintain a
comfortable room. The compressor will come on anytime that
the room temperature is 1.8°F above the desired temperature.
The fan operation is dependent on the fan mode selected,
either continuous or cycling.
Heating Mode
Pressing the 'Heat' button while the unit is in any mode,
including off, will put the unit into heating mode.
Heat Pump Models (PDH)
When the 'Heat' button is pressed initially the unit will energize
the electric resistance heat to quickly bring the room to the
set temperature. When the desired room temperature falls
1.8°F below the desired set temperature the unit will cycle
the compressor on and operate as a heat pump to maintain
the room temperature while running more efficiently than
resistance heat only models. If the room temperature should
fall more than 5°F from the set temperature the unit will run
the resistance heater. The fan operation is dependent on the
fan mode selected, either continuous or cycling. Dip switch 5
controls the fan mode, see "Dip Switch" setting elsewhere in
this manual.
When the outdoor coil temperature falls below 30°F for more
than 2 minutes the unit will operate the resistance heaters and
not the compressor. When the outdoor coil temperature reaches
45°F the compressor will be allowed to operate again.
Digital Control Panel
or Temperature
Heat/Cool Models (PDE)
After pressing the 'Heat' button, adjust the temperature
readout to the desired room temperature and the unit will cycle
the resistance heat on and off to maintain a comfortable room.
The heater will come on anytime that the room temperature
is 1.8°F below the desired temperature. The fan operation is
dependent on the fan mode selected, either continuous or
cycling. Dip switch 5 controls the fan mode, see "Dip Switch"
setting elsewhere in the manual.
Emergency Heat Operation
In the event of a compressor failure in heat pump mode the
compressor may be locked out to provide heat through the
resistance heater. This feature ensures that even in the unlikely
event of a compressor failure the room temperature can be
maintained until the compressor can be serviced. Dip switch 7
controls the emergency heat setting, see "Dip Switch" setting
elsewhere in the manual.
Fan Mode
Fan Only
Pressing the 'Fan Only' button will run the fan to allow for
air circulation in the room without operating the compressor
or heater regardless of the room or set temperature. The fan
speed selection is made by pressing either the 'High Fan' or
'Low Fan' button.
Cycle/Continuous
The owner may choose between fan cycling or fan continuous
mode based on property preference. (Note: Even heat
monitoring and quiet start/stop fan delay only operate in fan
cycle mode). Fan continuous mode is used to keep constant
airflow circulation in the room during all times the unit is 'ON'.
Fan cycle will conserve energy by only operating the fan while
the compressor or electric heater is operating. Dip switch 5
controls the fan mode, see "Dip Switch" setting elsewhere in
the manual.
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