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INSTALLATION INSTRUCTIONS
the crankcase heater remains de-energized after the
compressor is turned off.
Outdoor Fan Motor Operation
The outdoor unit control energizes the outdoor fan any time
the compressor is operating.
energized if a pressure switch or compressor overload
should open. Outdoor fan motor will continue to operate for
one minute after the compressor shuts off when the outdoor
ambient is greater than or equal to 100_F (37.8_C) to allow
for easier starting during next cooling cycle.
On CCA7, HCA7 and TCA7 models - The outdoor fan motor
is a PSC type. A fan relay on the control board turns the fan
off and on by opening and closing a high voltage circuit to the
motor. It does not change speeds between low and high
stage operation.
On CCA9, HCA9 and TCA9 models − The outdoor fan is an
ECM type. The motor control is continuously powered with
high voltage. The motor speed is determined by electrical
pulses provided by the PWM outputs on the control board.
The ECM motor RPM adjusts to outdoor conditions as
described in Table 3. The PWM output can be measured
between the PWM1 and PWM2 terminals on the circuit board
with a volt meter set to DC volts.
Table 3 − Outdoor Fan Motor PWM
Outdoor Temp (DC volts, Tolerance +/− 2%)
Low−Stage
High Stage
Model
Size
OAT 3 1045F/ 405C
OAT 3 1045F/ 405C
924
9.57
936
9.06
948
9.91
960
10.83
Time Delays
The unit time delays include:
S
Five minute time delay to start cooling operation when
there is a call from the thermostat or user interface. To
bypass this feature hold the "Cool To" or "Heat To"
button on the Observer Wall Control for 10 seconds.
S
Five minute compressor re−cycle delay on return from
a brown−out condition.
S
Two minute time delay to return to standby operation
from
last
valid
Communicating Wall Control only).
S
One minute time delay of outdoor fan at termination of
cooling mode when outdoor ambient is greater than or
equal to 100_F (37.8_C).
S
There is no delay between staging from low to high
and from high to low capacity. The compressor will
change from low to high and from high to low capacity
"on the fly" to meet the demand.
421 01 1701 00
The outdoor fan remains
Low & High Stage
OAT > 1045F/ 405C
10.88
11.90
10.23
11.90
11.04
11.90
11.70
11.90
communication
(Observer
R−410A Split System Air Conditioner
TROUBLESHOOTING
If the compressor fails to operate with a cooling call, Table 4
can be used to verify if there is any damage to the
compressor windings causing system malfunction.
Table 4 − Winding Resistance
Winding Resistance At 705F +/− 205F
(21.115C +/− 11.115C)
Winding
24
36
Start
1.40
1.29
(S−C)
Run
1.32
0.89
(R−C)
Systems Communication Failure
If communication with the Observer Communicating Wall
Control will flash the appropriate fault code. (See Table 6)
Check the wiring to the wall control, indoor and outdoor units.
Model Plug
Each control board contains a model plug. The correct model
plug must be installed for or the system to operate properly
(see Table 5).
Table 5 − Model Plug
Model
Model Plug
Number
Number
*CA724
HK70EZ040
*CA736
HK70EZ042
*CA748
HK70EZ044
HK70EZ046
*CA760
*CA924
HK70EZ009
*CA936
HK70EZ011
*CA948
HK70EZ013
HK70EZ015
*CA960
The model plug is used to identify the type and size of unit to
the control.
On new units, the model and serial numbers are input into
the board's memory at the factory. If a model plug is lost or
missing at initial installation, the unit will operate according to
the information input at the factory and the appropriate error
code will flash temporarily.
A FAST® Parts replacement board contains no model and
serial information. If the factory control board fails, the model
plug must be transferred from the original board to the
replacement board for the unit to operate.
NOTE: The model plug takes priority over factory model
information input at the factory. If the model plug is removed
after initial power up, the unit will operate according to the last
valid model plug installed, and flash the appropriate fault code
temporarily.
Pressure Switch Protection
The outdoor unit is equipped with high and low pressure
switches.
If the control senses the opening of a high or low pressure
switch, it will respond as follows:
1. De-energize the appropriate compressor contactor.
2. Keep the outdoor fan operating for 15 minutes.
3. Display the appropriate fault code (see Table 6).
4. After a 15 minute delay, if there is still a call for cooling
and the LPS or HPS is reset, the appropriate
compressor contactor is energized.
5. If LPS or HPS has not closed after a 15 minute delay,
the outdoor fan is turned off. If the open switch closes
anytime after the 15 minute delay, then resume
operation with a call for cooling.
48
60
1.52
0.60
0.64
0.49
Pin Resistance
(kOhms)
Pin 1−4
Pin 2−3
18
75
18
120
18
180
18
270
5.1
91
5.1
150
5.1
220
5.1
360
9
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