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PH14*B, PH15NB, PH16NC: Installation Instructions
CAUTION
!
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this caution may result in personal injury, equipment
damage or improper operation.
• Do not overcharge system with refrigerant.
• Do not operate unit in a vacuum or at negative pressure.
• Do not disable low pressure switch in scroll compressor applications.
• Compressor dome temperatures may be hot.
Follow these steps to properly start up system:
1. After system is evacuated, fully 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.
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.
Sequence of Operation
Turn on power to indoor and outdoor units. Transformer is energized.
Cooling
On a call for cooling, thermostat makes circuits R–O and 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, its contacts open, de–energizing contactor
and blower relay. Compressor and motors should stop.
NOTE: If indoor unit is equipped with a time–delay relay circuit, the
indoor blower will run an additional 90 seconds 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 continue to fall, R–W2 is made through second–
stage room thermostat. Circuit R–W2 energizes a relay, bringing on first
bank of supplemental electric heat and providing electrical potential to
second heater relay (if used). If outdoor temperature falls below setting
of outdoor thermostat (field installed option), contacts close to complete
circuit and bring on second bank of supplemental electric heat.
When thermostat is satisfied, its contacts open, de–energizing contactor
and relay. All heaters and motors should stop.
Quiet Shift-2
Quiet Shift-2, available on units with aluminum outdoor coils, is a field
selectable defrost mode (factory set to OFF), which will reduce the
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 the ON position.
When Quiet Shift-2 switch is placed in ON position, and defrost is
initiated, the following sequence of operation will occur:
– The compressor will be de--energized for approximately 1 minute,
then the reversing valve will be energized. A few seconds later, the
compressor will be re-energized and the normal defrost cycle starts.
Once defrost termination conditions have been met, the following
sequence will occur:
– The compressor will be de-energized for approximately 1 minute,
then the reversing valve will be de-energized. A few seconds later,
the compressor will be re-energized and the normal heating cycle
starts.
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Defrost
The defrost control is a time/temperature control which includes a field
selectable time period between defrost cycles (30, 60, 90, or 120 . For
non-Quiet Shift 2 boards the time period is selected using quick connects
located at the edge of the board. For Quiet Shift 2 boards the time period
is selected using DIP switches located on the board. For Quiet Shift 2
boards HK32EA011 and later used on Al coil product, the setting is
initial period only then varies with defrost length.
For all defrost controls, the defrost thermostat senses coil temperature
throughout the heating cycle. When the coil temperature reaches the
defrost thermostat setting of approximately 32°F (0°C), it will close,
which energizes the DFT terminal and begins the defrost timing
sequence. The timer starts only when the defrost thermostat is closed and
the contactor is energized.
Defrost mode is identical to cooling mode except that outdoor fan motor
stops and second–stage heat is turned on to continue warming
conditioned spaces.
Defrost Speedup
Quiet Shift-2 Models
To initiate a forced defrost, speedup pins (J1) must be shorted with a flat
head screwdriver for 5 seconds and RELEASED. If the defrost
thermostat is open, a short defrost cycle will be observed (actual length
depends on Quiet Shift-2 switch position). When Quiet Shift-2 is off,
only a short 30 second defrost cycle is observed. With Quiet Shift-2 ON,
the speedup sequence is approximately 3 minutes; 1 minute compressor
off period followed by 30 seconds of defrost with compressor operation.
When returning to heating mode, the compressor will turn off for an
additional minute.
If the defrost thermostat is closed, a complete defrost cycle is initiated. If
the Quiet Shift-2 switch is turned on, the compressor will be turned off
for two 1-minute intervals as explained previously.
For HK32EA012 and later boards, if Quiet Shift 2 is enabled, the
variable defrost intervals will be disabled to provide options where using
a specific setting is desired. In this case the 30, 60, 90, or 120 setting
will not change unless the dipswitch is changed, and power is cycled.
NOTE: Forcing a defrost will reset the defrost interval to the DIP switch
setting before resuming variable length intervals based on defrost cycle
lengths.
All Other Models
To initiate defrost, the defrost thermostat must be closed. This can be
accomplished as follows:
1. Turn off power to outdoor unit.
2. Disconnect outdoor fan motor lead from OF2 on control board (see
Fig.
13). Tape lead 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 temperature should
drop below closing point of defrost thermostat (approximately
30°F/-1.11°C).
5. Short between speedup terminals with a flat-blade screwdriver.
This reduces the timing sequence to 1/25th of original time. (See
Table
5.)
6. When you hear reversing valve change position, remove
screwdriver immediately; otherwise, control will terminate normal
10-minute defrost cycle in approximately 2 seconds.
NOTE: Length of defrost cycle is dependent upon length of time it takes
to remove screwdriver from test pins after reversing valve has shifted.
7. Unit will remain in defrost for remainder of defrost cycle time or until
defrost thermostat reopens at approximately 65°F (18.33°C) coil
temperature of liquid line.
8. Turn off power to outdoor unit and reconnect fan motor lead to OF2
on control board.
To initiate defrost, the defrost thermostat must be closed. This can be
accomplished as follows:
1. Turn off power to outdoor unit.
7
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