
CAUTION: To prevent personal injury wear safety
glasses, protective clothing, and gloves when handling
refrigerant.
CAUTION: Back seating service valves are not
equipped with Schrader valves. Fully back seat (counter
clockwise) valve stem before removing gage port cap.
CAUTION: Federal regulations require that you do not
vent refrigerant to atmosphere. Recover during system
repair or final unit disposal.
Follow these steps to properly start up the system:
1. Fully back seat (open) liquid and vapor service valves.
2. Unit is shipped with valve stem(s) front seated (closed) and
caps installed. Replace stem caps after system is opened to
refrigerant flow (back seated). Replace caps finger-tight and
tighten with wrench an additional 1/12 turn. Use a backup
wrench on valve body flats to prevent distortion of sheet
metal.
3. Close electrical disconnects to energize system.
4. Set room thermostat at desired temperature. Be sure set
point is below indoor ambient temperature.
5. Set room thermostat to HEAT or COOL and fan control to
ON or AUTO mode, as desired. Operate unit for 15
minutes. Check system refrigerant charge.
A. Sequence of Operation
NOTE: Defrost control board is equipped with a 5-minute lock-
out timer which may be initiated upon an interruption of power.
With power supplied to indoor and outdoor units, transformer is
energized.
COOLING
On a call for cooling, thermostat makes circuits R-O, R-Y, and
R-G. Circuit R-O energizes reversing valve, switching it to cooling
position. Circuit R-Y energizes contactor, starting outdoor fan
motor and compressor circuit. R-G energizes indoor unit blower
relay, starting indoor blower motor on high speed.
When thermostat is satisfied, contacts R-Y open, de-energizing the
contactor and blower relay. Compressor and motors should stop.
NOTE: If indoor unit is equipped with a time-delay relay circuit,
the blower runs an additional 90 sec to increase system efficiency.
HEATING
On a call for heating, thermostat makes circuits R-Y and R-G.
Circuit R-Y energizes contactor, starting outdoor fan motor and
compressor. Circuit R-G energizes indoor blower relay, starting
blower motor on high speed.
Should temperature in the dwelling continue to fall, R-W2 is made
through second-stage room thermostat. Circuit R-W2 energizes
supplemental electric heat. If outdoor temperature falls below
setting of outdoor thermostat (field-installed option), contacts
close to bring on an additional bank of supplemental electric heat.
When thermostat is satisfied, its contacts open, de-energizing
contactor and sequencer. All heaters and motors should stop after
all fan off delays.
QUIET SHIFT
Quiet Shift is a field-selectable defrost mode (factory set to OFF
position), which will eliminate occasional noise that could be
heard at the start of defrost cycle and restarting of heating cycle. It
is selected by placing DIP switch 3 (on defrost board) in ON
position.
When Quiet Shift switch is placed in ON position, and a defrost is
initiated, the following sequence of operation will occur. Revers-
ing valve will energize, compressor will turn off for 30 seconds,
then turn back on to complete defrost. At the start of heating cycle
after conclusion of defrost mode, reversing valve will de-energize,
the compressor will turn off for another 30 seconds, and the fan
will turn off for 40 seconds, before starting in the heating mode.
DEFROST
The defrost control is a time/temperature control which includes a
field-selectable time period (DIP switch 1 and 2 on the board)
between defrost cycles of 30, 60, 90, or 120 minutes (factory set at
90 minutes).
To initiate a forced defrost, two options are available depending on
the status of the defrost thermostat.
If defrost thermostat is closed, speedup pins (J1) must be shorted
by placing a flat head screw driver in between for 5 seconds and
releasing, to observe a complete defrost cycle. When the Quiet
Shift switch is selected, compressor will be turned off for two 30
second intervals during this complete defrost cycle, as explained
previously. When Quiet Shift switch is in factory default OFF
position, a normal and complete defrost cycle will be observed.
If defrost thermostat is in open position, and speedup pins are
shorted (with a flat head screw driver) for 5 seconds and released,
a short defrost cycle will be observed (actual length is dependent
upon the selected Quiet Shift position). When Quiet Shift switch is
in ON position, the length of defrost is 1 minute (30 seconds
compressor off period followed by 30 seconds of defrost with
compressor operation). On return to heating operation, compressor
will again turn off for an additional 30 seconds and the fan for 40
seconds. When the Quiet Shift is in OFF position, only a brief 30
second cycle will be observed.
If it is desirable to observe a complete defrost in warmer weather,
the thermostat must be closed as follows.
1. Turn off power to outdoor unit.
2. Disconnect outdoor fan motor lead from OF2 on control
board (See Fig. 19). Tape to prevent grounding.
3. Restart unit in heating mode, allowing frost to accumulate
on outdoor coil.
4. After a few minutes in heating mode, liquid line tempera-
ture should drop below closing point of defrost thermostat
(approximately 30°F).
NOTE: Unit will remain in defrost until defrost thermostat
reopens at approximately 80°F coil temperature at liquid line or
remainder of defrost cycle time.
5. Turn off power to outdoor and reconnect fan motor lead to
OF2 on control board after above forced defrost cycle.
XIV. CHECK CHARGE
A. Unit Charge
Factory charge is shown on unit rating plate. To check charge in
cooling mode, refer to Cooling Only Procedure. To check charge
in heating mode, refer to Heating Check Chart Procedure.
With unit operating, charge Puron units with liquid using a
commercial-type metering device in manifold hose. Charge refrig-
erant into suction line. Some refrigerant cylinders may contain a
dip tube that allows liquid refrigerant to flow from cylinder in
upright position. Check cylinder label for correct position to allow
liquid flow.
B. Cooling Only Procedure
NOTE: If subcooling charging conditions are not favorable,
charge must be weighed in accordance with unit rating plate ±0.6
oz/ft of 3/8-in. liquid line above or below 15 ft respectively.
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