Emerson Liebert iCOM Manual De Usuario
Operation
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Liebert
®
iCOM
®
Setting the counter to 0 will reset the alarm without the need of pressing the reset button on the
display. Even if the pressure in the system drops below the alarm point, the compressor will remain
Off until the system is reset.
Advanced DX High-Pressure Protection
Advanced high-pressure protection routines are intended to prevent high-pressure lockouts. Liebert
Advanced high-pressure protection routines are intended to prevent high-pressure lockouts. Liebert
iCOM does this by constantly monitoring the condensing pressure. If the control finds that pressure is
not maintained, the compressor capacity will automatically adjust to help lower the operating
pressure. This built-in intelligence operates the compressor at a slightly reduced capacity, reducing
the chance of a total loss of cooling created by a high-pressure lockout.
This feature is standard on units equipped with liquid line transducers and these compressor types:
This feature is standard on units equipped with liquid line transducers and these compressor types:
• 4-Step
• Digital Scroll
• Tandem Digital
• Digital Scroll
• Tandem Digital
Digital Scroll High Temperature
A protective maximum operating compressor temperature limit is imposed on units with digital scroll
A protective maximum operating compressor temperature limit is imposed on units with digital scroll
compressor(s) with thermistor. If the digital scroll temperature reaches the maximum temperature
threshold, the compressor will be locked out for at least 30 minutes and an alarm will be annunciated.
If after 30 minutes the temperature has cooled to a safe operating temperature, the compressor will
resume operation.
Each time a high-temperature alarm occurs, HT 1 Alarm Counter (Service Menu, Diagnostics) or
Each time a high-temperature alarm occurs, HT 1 Alarm Counter (Service Menu, Diagnostics) or
HT 2 Alarm Counter (Service Menu, Diagnostics) is increased by one. Once these counters reach five
occurrences in a rolling four-hour period, the compressor will be locked out. The alarm can be reset
once the temperature returns to a safe level by:
1. Setting the counter back to 0 from the display and pressing the alarm reset button.
2. Shutting Off power to the control board by turning the cooling unit's main power disconnect
1. Setting the counter back to 0 from the display and pressing the alarm reset button.
2. Shutting Off power to the control board by turning the cooling unit's main power disconnect
switch Off and On.
3.1.6 Compressor Timing—Short-Cycle Protection
To help maximize the life of your compressor(s), there is a start-to-next start delay for each single
compressor.
NOTE
If the unit is equipped with manual reset high head pressure switches, or if the auto reset high
If the unit is equipped with manual reset high head pressure switches, or if the auto reset high
head pressure switches don’t reset, the compressor will not be turned back on, but there will be
a 30-second delay from when the high head pressure situation occurs and when the alarm is
annunciated.
NOTE
Advanced DX high-pressure protection is not supported on standard scroll compressors.
Advanced DX high-pressure protection is not supported on standard scroll compressors.
NOTE
This delay may cause a short cycle if there is a very light room load. A short cycle means that
This delay may cause a short cycle if there is a very light room load. A short cycle means that
the compressor has cycled On and Off 10 times in the past hour. This is typically caused by a
lack of load or control settings set too tight (see 3.3.2 - Compressor Control for more
information on the control adjustment). Should short cycling still occur after the control has
been adjusted, contact technical support at 800-543-2778 to adjust the minimum compressor
Off delay.