Safety Devices and the UPM Controller | 11EC Series
T111970289 (2015/01)EC Series
• High pressure switch located in the refrigerant
discharge line and wired across the HPC
terminals on the UPM
• Low pressure switch located in the unit
refrigerant suction line and wired across
terminals LPC1 and LPC2 on the UPM.
• Water side freeze protection sensor, mounted
close to condensing water coil, monitors
refrigerant temperature between condensing
water 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 26°F, however this can be changed to
15°F by cutting the R42 resistor located on top
of DIP switch SW1. (Figure #13)
•
Figure # 10
• The optional condensate overflow protection
sensor (standard on horizontal units) is
located in the drain pan of the unit and
connected to the ‘COND’ terminal on the UPM
board. (Figure #14)
Figure # 11
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 down 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 and does not need to be reset.
UPM Board Dry Contacts are Normally Open
(NO)
UPM Board Factory Default Settings
TEMP
26°F
LOCKOUT
2
RESET
Y
ALARM
PULSE
TEST
NO
HOT/DRY ALARM
NO
UPM DIP SWITCH DEFAULT POSITION
lockout 42
reset
RY
alarm
Cont pulse
test
yes no
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