Setting Temperature Compensation - Vertiv Liebert iCOM DP400/500 Installer/User Manual

• Compressor 1A is digital-scroll and Compressor 1B is fixed, standard-scroll. These comprise tandem-
compressor set 1.
• Compressor 2A is digital-scroll and Compressor 2B is fixed, standard-scroll. These comprise tandem-
compressor set 2.
Selecting Event Type and Setting Alarm/Warning Notification
tandem compressors. If an alarm condition affects both tandem sets, tandem-compressor set 1 acts as the lead until the
alarm is reset and the compressors reactivated. Once the alarm is cleared and the compressors activated, the lead-lag
settings chosen for Compressor Sequence resume, see
The compressors operate in stages to maintain the selected temperature setpoint. The stages are defined by the
compressors that operate during that stage and the begin operating and ramp up or down based on the call-for-cooling
percentage, see Table 3.2 below, for typical operation. The loading routine may vary based on transient room conditions,
but in the tandem set the compressors operate as follows: The digital scroll compressor in the lead set activates on a call for
cooling and ramps between 20% and 100% to meet the requirement. If the call exceeds the digital scroll's capacity, the
fixed-capacity compressor activates and the digital scroll ramps down.
Table 3.2 Cooling Stages and Compressor Operation in a Dual-Circuit System with Tandem Compressors
Cooling Stage
1
2
3
4

3.1.5 Setting Temperature Compensation

Temperature compensation provides protection from changes that affect capacity and heat load by monitoring
temperature conditions and fan-speed settings, then automatically adjusting the temperature setpoint. Changes that may
cause temperature compensation are floor tile removal in non-cold aisle areas, incorrect supply temperature setpoint, unit
failure in a neighboring zone, or unexpected heat load fluctuations at rack equipment.
Temperature compensation is also tied-in to cascade/stand-by operation in Teamwork Mode 3. See
Optimized Aisle Operation
1. Touch
The TEMPERATURE COMPENSATION secondary panel opens.
2. Select the Compensation Type, then touch Save. The setpoint is updated.
• Return temperature compensation cannot be used when both fan and cooling control is set to Return.
• Supply temperature compensation requires the following settings:
Temperature Control Sensor: Supply Sensor
Fan Control Sensor: Remote Sensor
NOTE: When temperature compensation is enabled and active, theTemperature Setpoint Act field on the Temperature
Control setpoints panel displays the adjusted setpoint value.
NOTE: Depending on the type of thermal management unit, included components, and control settings of your
system, all of the options listed may not be available on your iCOM display.
3 Service Operation
Compressor(s) Operating
Digital-scroll 1A modulating
Digital-scrolls 1A and 2A modulating
Digital-scrolls 1A and 2A modulating, Fixed 1B
Digital-scrolls 1A and 2A modulating, Fixed 1B and 2B
on page 66.
, then > Setpoints >Temperature Compensation.
on page 45 describes the alarm events associated with the
Setting Compressor Options on page 39.
Unit Capacity to Meet Room Load
Up to 25%
25% to 50%
50% to 75%
75% to 100
Teamwork Mode 3—
27