Sears GT Series Installation Instructions Manual page 23

• The condensate overflow protection sensor is located in the drain
pan of the unit and connected to the "COND" terminal on the
UPM board. See Fig. 70.
A14123
Fig. 70 - Condensate Overflow Protection Sensor Location
30°F
2
Y
PULSE
NO
lockout
reset
2
Y
alarm pulse
test no
The UPM Board includes the following features:
• ANTI-SHORT CYCLE TIMER: 5 minute delay on break
timer to prevent compressor short cycling.
• RANDOM START: Each controller has an unique random start
delay ranging from 270 to 300 seconds on initial power up to
reduce the chance of multiple unit simultaneously starting at the
same time after power up or after a power interruption, thus
avoiding creating large electrical spike.
• LOW PRESSURE BYPASS TIMER: If the compressor is
running and the low pressure switch opens, the controller will
keep the compressor ON for 120 seconds. After 2 minutes if the
low pressure switch remains open, the controllers will shut down
the compressor and enter a soft lockout. The compressor will not
be energized until the low pressure switch closes and the
anti-short cycle time delay expires. If the low pressure switch
opens 2-4 times in 1 hour, the unit will enter a hard lockout. In
order to exit hard lockout power to the unit would need to be reset.
• BROWNOUT
/ SURGE / POWER INTERRUPTION
PROTECTION: The brownout protection in the UPM board
will shut does the compressor if the incoming power falls below
18 VAC. The compressor will remain OFF until the voltage is
above 18 VAC and ANTI-SHORT CYCLE TIMER (300
seconds) times out. The unit will not go into a hard lockout.
• MALFUNCTION OUTPUT: Alarm output is Normally Open
(NO) dry contact. If pulse is selected the alarm output will be
pulsed. The fault output will depend on the dip switch setting for
"ALARM". If it is set to "CONST", a constant signal will be
produced to indicate a fault has occurred and the unit requires
inspection to determine the type of fault. If it is set to "PULSE", a
pulse signal is produced and a fault code is detected by a remote
device indicating the fault. See L.E.D Fault Indication below for
blink code explanation. The remote device must have a
malfunction detection capability when the UPM board is set to
"PULSE".
NOTE: If 24 VAC output is needed, R must be wired to
ALR-COM terminal; 24 VAC will be available o the ALR-OUT
terminal when the unit is in the alarm condition.
• DISPLAY OUTPUT: The Display output is a pulse output
connected to the Unit Diagnostic Display (UDD) and it pulses
24VAC when the unit is in an lockout alarm condition.
• TEST DIP SWITCH: A test dip switch is provided to reduce all
time delays settings to 10 seconds during troubleshooting or
verification of unit operation.
[]NIT DAMAGE AND/OR OPERATION HAZARD
Failure to follow this caution may result in unit damage
and/or improper equipment operation.
Operation of unit in test mode can lead to accelerated wear
and premature failure of components. The "TEST" switch
must be set back to "NO" after troubleshooting/servicing.
FREEZE SENSOR: The default setting for the freeze limit trip as
26°F (sensor number 1); however this can be changed to 15 °F by
cutting the R30 resistor located on top of the DIP switch SWl.
Since freeze sensor 2 is dedicated to monitor the evaporator coil, it
is recommended to leave the factory default setting on the board.
The UPM controller will constantly monitor the refrigerant
temperature with the sensor mounted close to the condensing
water coil between the thermal expansion valve and water coil. If
temperature drops below or remains at the freeze limit trip for 30
seconds, the controller will shut the compressor down and enter
into a soft lockout condition. Both the status LED and the Alarm
contact will be active.
The LED will flash the code associated with this alarm condition
three (3) times. If this alarm occurs 2 times (or 4 if Dip switch is set
to 4) within an hour, the UPM controller will enter into a hard
lockout condition. It will constantly monitor the refrigerant
temperature with the sensor mounted close to the evaporator
between the thermal expansion valve and evaporator coil as
shown in Fig. 69.
If temperature drops below or remains at the freeze limit trip for
30 seconds, the controller will shut the compressor down and
enter into a soft lockout condition. Both the status LED and the
alarm contact will be active. The LED will flash the code
associated with this alarm condition six (6) times. If this alarm
occurs 2 times (or 4 if Dip switch is set to 4) within an hour, the
controller will enter into a hard lockout condition.
[]NIT DAMAGE AND/OR OPERATION HAZARD
Failure to follow this caution may result in unit damage
and/or improper equipment operation.
Freeze sensor will not guard against the loss of water. A
flow switch is recommended to prevent the unit from
running if water flow is lost or reduced.
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