Friedrich HEAT PUMPS User Manual

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The vent control lever is located behind the front cover on the 
left side of the unit. The unit is shipped in the closed position 
with a locking screw in place. The screw must be removed to 
operate the lever.  When the lever is back, (OPEN), outside air 
is mixed with indoor air.  When the lever is forward, (CLOSED), 
no out side air is admitted into the room and room air is re cy cled 
through the unit.
G. Fresh Air Vent Con trol
NOTE:  The vent should remain closed for peak operating ef fi  cien cy.
Auxiliary Fan Control
The Smart Center also has the ability to control a 24VAC relay 
to activate an auxiliary, or transfer, fan. The outputs are listed as 
F1 and F2 on the control board.
To connect the relay, simply wire one side of the relay to F1 and 
the other side to F2. Anytime that the PTAC fan runs the terminals 
will send a 24VAC signal to the relay. The relay must be 24 VAC, 
50mA or less.
Note: The relay and auxiliary fans must be fi eld supplied. 
NOTE: It is the installer's responsibility to ensure that all control 
wiring connections are made in accordance with the installation 
instructions. Improper connection of the thermostat control wiring 
and/or tampering with the unit's internal wiring can void the 
equipment warranty and may result in property damage, personal 
injury or death. Other manufacturer's PTACs and even older 
Friedrich models may have different control wire connections. 
Questions concerning proper connections to the unit should be 
directed to the factory.
Wire Size
Maximum Length
#24
400 ft.
#22
600 ft.
#20
900 ft.
#18
1500 ft.
#16
2000 ft.
Desk Control Terminals
The Friedrich PD model PTAC has built-in provisions for 
connection to an external switch to control power to the unit. The 
switch can be a central desk control system or even a normally 
open door switch.
For desk control operation connect one side of the switch to the 
D1 terminal and the other to the D2 terminal (See fi gure  13).  
Whenever the switch closes the unit operation will stop.
Maximum Wire Length for Desk Control Switch
Note: The desk 
control system and 
switches must be 
fi eld supplied.
H. Air Discharge Grille
The air discharge grille can be redirected to blow air either straight up or at an angle into the room.  To change the air fl ow di rec tion, re move 
the front cover, locate and remove the six grill retaining screws.  Reverse the ends of the grille and refasten the grille to the cover.
Moving parts hazard.
Turn off electric power before 
servicing this component.
Failure to do so can result in property 
damage, personal injury and/or death.