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PA4G: Installation Instructions
interface board (IFB). Verify that static pressure is in the acceptable
range for the speed tap to be used for dehumidification cooling.
7. Use any spare vinyl plugs to cap any unused speed tap wires.
HIGH
QC5
07
09
0L0
08
ALO
C9
C4
QIL
Z2
06
04
A7
D5 D3
C7
JW5
R2
QCB
Y
SSTZ-8
Fig. 11 – Interface Fan Board (IFB)
Single Speed Cooling with Higher Electric Heat Speed
This unit can also be configured to operate with single speed cooling and
a higher speed for an accessory electric heater.
1. Using
Fig.
11, move the two pin DEHUM jumper from the "STD"
position to the "DEHUM" position.
2. See
Table 2
for minimum airflow for electric heat operation. Add
electric heater and filter pressure drop to duct system static pressure
to determine total external static pressure.
3. Select speed tap from
Table 5
from
Table
2.
4. Remove the vinyl cap off of the desired speed tap wire (Refer to
Table 3
for color coding).
5. Connect the desired speed tap wire to the "HIGH" terminal on the
interface fan board (IFB).
CAUTION
!
UNIT OPERATION HAZARD
Failure to follow this caution may result in unit component damage or
improper operation.
To use this mode, a speed connection must be made on the "HIGH"
terminal that meets or exceeds the minimum airflow found in
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
LOW
COM
QC4
QC3
KL
KZ
DCR
QCR
C
R13 C8
R11
Q1
D2
QC1
Q3
AL2
RL
G1
01
G2
R9
AB A15
F1
C0
Z1
U1
R4
RL4
C3
JWZ
R3 R5 R6
P2
JW3
P4
R W2 Y
C
W3 W3 W2 W2 C
JW4
P1
Y2
Y1
W3
W2
DH G
C R
Y
that will achieve required airflow
–
Table 3 – Color Coding for Indoor Fan Motor Leads
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury or death.
Disconnect electrical power to the unit and install lockout tag before
changing blower speed.
Continuous Fan Operation
When the DEHUM feature is not used, the continuous fan speed will be
the same as cooling fan speed. When the DEHUM feature is used, the
continuous fan will operate on IFB "LOW" speed when the DH control
lead is not energized, or IFB "HIGH" speed when the DH lead is
energized (see
Fig.
Cooling Sequence of Operation
With the room thermostat SYSTEM switch in the COOL position and
the FAN switch in the AUTO position, the cooling sequence of operation
is as follows:
When the room temperature rises to a point that is slightly above the
cooling control setting of the thermostat, the thermostat completes the
A09059
circuit between thermostat terminal R to terminals Y and G. These
completed circuits through the thermostat connect contactor coil (C)
(through unit wire Y) and time delay relay (TDR) (through unit wire G)
across the 24-V secondary of transformer (TRAN).
The normally open contacts of energized contactor (C) close and
complete the circuit through compressor motor (COMP) to condenser
(outdoor) fan motor (OFM). Both motors start instantly.
A set of normally open contacts on the interface fan board (IFB) are
closed which energizes a circuit to the indoor fan motor (IFB).
NOTE: Once the compressor has started and then has stopped, it should
not be started again until 5 minutes have elapsed.
The cooling cycle remains on until the room temperature drops to a point
that is slightly below the cooling control setting of the room thermostat.
At this point, the thermostat breaks the circuit between thermostat
terminal R to terminals Y and G. These open circuits deenergize
contactor coil C and IFB. The condenser and compressor motors stop.
After a 90-second delay, the blower motor stops. The unit is in a standby
condition, waiting for the next call for cooling from the room thermostat.
Table
2.
14
Black = High Speed
Orange = Med-High Speed
Red = Med Speed
Pink = Med-Low Speed
Blue = Low Speed
WARNING
!
11).
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