Electrical | 11LM Series Heat Pump
8 733 905 315 (2013/9)Revised 09-13
• Evaporator freeze protection sensor, mounted
between the thermal expansion device and the
evaporator, monitors refrigerant temperature
between the evaporator coil and thermal
expansion valve. If temperature drops below or
remains at freeze limit trip for 30 seconds, the
controller will shut down the compressor and
enter into a soft lockout condition. The default
freeze limit trip is 30°F. (Figure#11)
Figure # 11
• The condensate overflow protection sensor is
located in the drain pan of the unit and
connected to the ‘COND’ terminal on the UPM
board. (Figure #)
Figure # 12
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. If, after 120 seconds 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.
UPM Board Factory Default Settings
TEMP
30°F
LOCKOUT
2
RESET
Y
ALARM
PULSE
TEST
NO
UPM DIP SWITCH DEFAULT POSITION
lockout 42
reset
RY
alarm
Cont pulse
test
yes no
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