Installation guide

Defrost Time
Selectors
Thermosta_
Low Voltage
Connector
03 1:_
->
_C
_fS_
NNNNNNNN_
°°'c=ff_' __c:5 _ o_:_ _ _ _i
..... HK38EA00_
Reserved for
Future Use
Fig. 14--Control Board
Low Pressure
_ Switch Connector
High Pressure
Switch Connector
*-Thermistor
Connection
To Run
Capacitor
] O.D.F. Connection
]Crankcase Heater
Connection
A01192
STATUS F[_'CTION LIGHTS
A system control STATUS function light is located on the outdoor
unit control board. (See Fig. 14.) The STATUS light provides
indication signals for several system operations. See Table 4 for
codes and definitions. Table 4 also provides the order of signal
importance.
NOTE: Only one code will be displayed on the outdoor unit
control board (the most recent, with the highest priority).
FACTORY DEFAULTS
Factory defaults have been provided in the event of fi_ilure of
outdoor air thermistor and, or outdoor coil thermistor. Refer to
Table 6 for default and ffmetion.
ONE MINUTE SPEED CHANGE TIME DELAY
When compressor changes speeds fi'om high to low or low to high,
there is a 1-minute time delay before compressor restarts. The
outdoor fan motor remains running.
COMPRESSOR OPERATION
When the compressor operates in second stage operation, the
motor rotates clockwise. Both the lower and upper pistons are
eccentric with the rotating crankshaft, and both compress refrig-
erant. When the compressor operates in single stage operation the
motor reverses direction (rotates counter-clockwise). The lower
piston becomes idle and the upper piston compresses refrigerant.
During single capacity operation the "start" and "run" wind-
ings are reversed.
CRANKCASE HEATER OPERATION
The two-speed control board energizes the crankcase heater during
unit's oft" cycle.
OUTDOOR FAN MOTOR OPERATION
The two-speed control energizes outdoor fan any time compressor
is operating. The outdoor fan remains energized during the
l-minute compressor speed change time delay and if a pressure
switch or compressor overload should open. Outdoor fan motor
Table 7--Two-Speed Compressor
(Winding Resistance at 70°F + 20°)
WINDING 024 036/037 048
Start (S-C) 2.280 1.850 1.459
Run (R-C) 0.770 0.745 0.552
060
0.740
0.356
12
will continue to operate for one minute after the compressor shuts
off when the outdoor ambient is greater than 100°F.
After termination ofa defi'ost cycle, the outdoor fan delays coming
on for 20 sec. This allows refrigerant system to recover outdoor
coil heat and minimize the "steam cloud" effect.
DEFROST TIME SELECTION
The defi'ost interval can be field selected, dependent on local or
geographical requirements. It is factory set at 90 minutes but can
be changed to either 30, 60, or 120 minutes. To select defi'ost time,
set dip switches located on the left side of the unit board (See Fig.
14). See Table 5 for Defi'ost Dip Switch Settings.
DEFROST
The dual capacity control logic for defrost function is time and
temperature initiated, time or temperature terminated.
Defrost only occurs at outdoor temperatures less than 50°F. The
control initiates del}ost when outdoor coil thermistor is 30°F (±2 °)
or less, and selected defrost time (intelwal) has been accumulated
during unit operation. Termination occurs when coil thermistor
reaches 80°F (±5 °) or defrost period reaches a maximum of 10
minutes. Defi'ost will occur at the compressor capacity that is being
called lbr. During defrost, unit operates in high or low capacity,
energizes reversing valve O and auxiliary heat W2, and de-
energizes outdoor fan. Upon termination, there is a 20-see delay in
outdoor fan being energized.
FIELD-INITIATED FORCED DEFROST
By placing a jumper across forced defrost temlinals (See Fig. 14)
for a mininmm of 5 sec and then removing it, a del}ost cycle can
be initiated. The cycle occurs only if outdoor ambient is less than
50°F, regardless of outdoor coil temperature. The cycle temlinates
when coil thermistor reaches 80°F (±5 °) or defrost period reaches
a maxinmm of 10 minutes.
COMPRESSOR VOLTAGE FAILURE (6 FLASHES)
The control senses the voltage of the compressor run winding. If
compressor voltage (Vc) is less than 90v when control board is
calling for compressor operation, control de-energizes compressor
contactor for 15 minutes with outdoor fan running. After 15
minutes (provided there is a call for Y1 or Y2), control attempts to
start compressor. During this time, a code of 6 flashes appears at
control board. If Vc trip occurs 3 consecutive times during a Y1
request, then low capacity operation is locked out and control
responds to Y2 requests until a reset occurs. If 3 consecutive trips
occur in a combination of Y1 and Y2 or all Y2 requests, then both
low and high capacity operation will be locked out. The compres-
sor voltage failure (6 flashes) can be caused by:
• compressor internal overload trip (refer to Table 7 for con'ect
winding resistance)
• no 208/230 volt power supply to outdoor unit
• failed compressor contactor(s)
• failure of start relay to pick-up properly
• improper wiring
PRESSURE SWITCH PROTECTION
The outdoor unit is equipped with high- and low-pressure
switches. If the control senses the opening of the high or low
pressure switch, it will respond as fbllows: