Setting Q15 Options - Vertiv Liebert iCOM DP400/500 Installer/User Manual

Setting Low Pressure Time Delay
At compressor startup, a low pressure condition is ignored for a set period to avoid false trips due to bubbles in the
refrigerant or other misreading of the low-pressure device.
NOTE: The factory default setting is a three minute delay for air cooled units and a zero to one minute delay for water
cooled units.
1. Touch
2. Use the Winter Start Delay slider to select the number of minutes for the delay, and touch Save.
Adjusting Ball Valve Pressure Offset
NOTE: Only a properly trained and qualified technician should modify the motorized ball valve setting.
The number of times the valve opens and closes is adjusted based on added pressure offset.
1. Touch
2. Use the Ball Valve Setpoint Offset slider to select amount of pressure added to open the valve wider, and touch
Save.
Compressor Sequencing for Balancing Run Times
Compressor sequencing, available in two compressor cooling units, allows assigning a lead compressor or allowing
automatically leading with the compressor with the lower run hours logged.
When Auto is selected, the following applies as iCOM attempts to maintain equal run time of the compressors:
• If only one compressor is available because of safety delays, it is given first priority to start/stop.
• If both compressors are off, the compressor with fewer run hours is the next to start.
• If both compressors are operating, the compressor operating for the longest time since the last start is the first
to shut off.
NOTE: Automatic compressor sequencing will not power off a compressor if it is required to properly condition the
space.
To Set Up Compressor Sequencing
1. Touch
2. Select the Compressor Sequence option to use, and touch Save.

3.3.6 Setting Q15 Options

1. Touch
2. Make adjustments as needed and click Save. The option settings are updated.
• Touch Cancel to discard the changes without saving.
40
, then > Options Setup > Compressor Settings.
, then > Options Setup > Compressor Settings.
, then > Options Setup > Compressor Settings.
, then > Options Setup > Q15 Settings. The Q15 SETTINGS panel displays.
Vertiv™ | Liebert® iCOM™ Installer/User Guide