Friedrich VERT-I-PAK VHA-18K75RTP, Service & Parts Manual

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23 PB
OPERATION
Compressor Lock Out Time
The lockout feature ensures that the compressor is de-energized for a period of time. The timer varies randomly
from 180 to 240 seconds.
The compressor lockout is initiated every time the compressor is “off” due to:
(1) Satisfying the T-stat temperature set point
(2) Changing mode to fan only or heat
(3) Turning the unit off
(4) Power is restored after failure
(5) Line power is restored from a brown out condition
Cooling Fan Delay
This is only for t-stat Fan Auto Mode only.
When unit cycles cooling ON – starts the fan 5 seconds EARLY. When unit cycles cooling OFF – DELAYS the fan off for 30
seconds
Heating Fan Delay
This is only for Fan Auto Mode (Fan cycles with cool/heat operation) and not for continuous fan mode. When unit cycles Heat-
ing ON – starts the fan 5 seconds EARLY. When unit cycles Heating OFF – DELAYS the fan off for 15 seconds.
Continuous fan operation enables fan to run continuously.
Fan Speed Change Delay
Relay activation is delayed by a minimum number of seconds. The default for this value is 2 seconds and is used to eliminate
relay chatter.
Room Air Sampling Feature
The room air sampling feature maintains a balanced temperature throughout the room by circulating the air for 90 seconds
once every 9 minutes that the unit is not running when it is set to cooling or heating mode. By circulating the air, the unit can
detect hot or cold areas in the room and operate the unit to cool or warm the room as neces-sary. This function is only avail-
able when the fan mode is set to ‘AUTO’ during COOL or HEAT Mode.
Low Voltage Interface Connections
All Vert-I-Pak units have a low voltage interface connector through
which a Remote Wall Thermostat, Desk Control and Auxiliary Fan’s
Relay can be connected. The interface connector is located on the electronic control board.
Interface Connector Definitions
FP Factory use only.
(Ensure there is no jumper at FP an F2)
F2 Used with F1 to provide 24 VAC to external
fan relay. (Ensure there is no jumper at FP an F2
F1 Used with F2 to provide 24 VAC to external fan relay.
D2 Used with D1 for desk control on or off operation.
D1 Used with D2 for desk control on or off operation.
C Common Ground TerminaL
GH Call for high fan
GL Call for low fan
B Call for heat pump reversing valve
Y Call for compressor
W Call for heating
R 24V Power from Electronic Control to Wall
Figure 301 (Inteface Connections) Figure 302 (Inteface Connections)