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PH14*B, PH15NB, PH16NC: Installation Instructions
2. Disconnect outdoor fan motor lead from OF2 on control board for
units using PSC motors and from ODF terminal on units with ECM
motor (see
Fig.
12). 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
4.)
PARAMETER
30–minute cycle
50–minute cycle
90–minute cycle
10–minute cycle
5 minutes
T1 - ENABLES DEFROST
TIMER.MUST BE
ENERGIZED FOR
DEFROST TIMER
TO START
C - COMMON
O - REVERSING VALVE
THERMOSTAT INPUTS
Fig. 12 – Non-Quiet Shift-2 Control Board for Units with PSC
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Table 4 – Defrost Control Speedup–Timing Sequence
MINIMUM
(MINUTES)
27
45
81
9
4.5
OUTDOOR FAN
RELAY
DEFROST THERMOSTAT
MUST BE CLOSED BEFORE
DEFROST TIMER BEGINS
Y OUTPUT TO PRESSURE
SWITCHES AND CONTACTOR
SPEEDUP
Motors
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 for units using PSC motors and to ODF terminal
on units with ECM motor.
MAXIMUM
(MINUTES)
33
55
99
11
5.5
Fig. 13 – Non-Quiet Shift-2 Control Board for units with ECM
A05332
8
SPEEDUP
(NOMINAL)
7 sec
12 sec
21 sec
2 sec
1 sec
Motor
A170138
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