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Operation
The Value setting is the factory default setting on free-cooling and dual cooling units. If the tempera- ture difference between the second source cooling fluid parameter, Free-cooling Fluid Temperature (User Menu, Sensor Data) and room air is equal to or greater than the adjustable DT Between Room Air / FC Fluid (Service Menu, Setpoints) value, then the second source cooling fluid will be used to provide at least partial cooling (delta T between room and glycol = true).
Sensors used for this delta T are: room/local sensor or the return air sensor; and the glycol sensor. If this delta T is true, the following actions will be performed:
1.The Free-Cooling Status indication will show “On” instead of “Off”.
2.The compressor band will be shifted to the right by 100%, and within the first 100% the free- cooling valve band will take place (see Figure 18).
Figure 18 Second cooling source and compressorized cooling
Temp Setpoint: 70°F
Proportional Band: 8°F
Deadband: 2°F
Valve | Valve 100% | Cool 1 | Cool 2 |
Closed | Open | On | On |
| + 100% | | |
½ Dead- | Cooling | | |
| | |
band
2ndComp Source
| ½ Proportional Band | ½ Proportional Band | + 200% |
| Band1: 2nd Source | Band 2: Compressors |
| Cooling |
Increasing Temperature
Minimum Chilled Water Temperature—This feature permits the user to select the minimum chilled water temperature that allows simultaneous operation of the second cooling source (chilled water control) and compressor control. This feature is enabled in the Service menu under Setpoints, parameter Minimum CW Temp.
Below this minimum chilled water setpoint, parameter Minimum CW Temp Value, (Service Menu, Setpoints), the control will operate ONLY the second cooling source control, i.e., the compressor is locked out. Above the minimum chilled water setpoint, assuming the fluid temperature is below the return room air temperature (delta T between room and glycol = true), the control will operate the second cooling source control and compressor control simultaneously if needed.
If the Minimum CW Temp is disabled, the second cooling source temperature is ignored, the control will always operate the second cooling source and compressors simultaneously when the load requires it.
Liebert iCOM
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Table of Contents
Teamwork
Installing a Liebert Icom UNIT-TO-UNITNETWORK
Mounting a Large Display on a Wall
Figures
Tables
Features
Large and Small Displays
ESC
Keyboard icons and functions
Icon Key Name Function
Status menu, large display, graphical view
Accessing Submenus
Accessing Submenus on Small Displays
Accessing Submenus on Large Displays
Navigating Through the Liebert iCOM Menus
Entering a Password
Menu tree-Small display, stand-alone or networked
Status Menu System View Status Menu Unit 1 View User Menu
Service Menu Unit
Advanced Menu Unit
Viewing Multiple Units with a Networked Large Display
Service Menu Unit #
Advanced Menu Unit #
SET
User menu icons
Service menu icons
Single Unit Functions
Unit/Fan Control Start Stop
Loss of Power Alarm
Fan Alarm / Fan Protection Settings
VSD Setpoint VSD Fan Speed Setting
Autorestart
High Pressure Alarm
Pump Down
Compressor Timing-Units With Two Compressors
Digital Scroll High Temperature
Compressor Sequencing
Motorized Ball Valve in Digital Scroll Units
Service Offset-Changing System Pressure Settings
MBV Operation After Compressor is Turned Off
Temperature Proportional Band
Temperature proportional band
Compressor Control
Compressor Proportional Bands
One Single-Step Compressor Without Unloaders-One-Step
Two Single-Step Compressors Without Unloaders-Two-Step
Two Compressors With Unloaders-Four-Step
Two compressors with unloaders four-step
Digital Scroll Compressors
Digital scroll capacity modulation, 10-100% variable
Temperature Control-Second Cooling Source
Differential Temperatures / Controls Comparator Circuit
Delta T Temperature Difference Between Room and Glycol
Chilled Water Control
Second cooling source and compressorized cooling
Temperature Control-Reheat
Reheat configuration types
Glycool Cooling-Free-Cooling
Dual Cooling Source
Off ½ Proportional Band Decreasing Temperature
Heat On ½ Dead Band 100%
Tight Mode
SCR Reheat
Standard Mode
Humidification Dehumidification
Humidity Control
Humidification
Parameters for infrared humidifier control
Humidification Infrared Humidifier
External Humidifier Control-Optional
Dehumidification With Comp settings
Dehumidification
Dehumidification Low Limit
Dehumidification Compressor Quantity
Control Types
Temperature and Humidity Control Types
Reheat During Dehumidification
Humidity Sensor Reading Control Types
High and Low, Temperature and Humidity Events
Supply Limit-Optional
User Inputs / Customer Inputs
Customer inputs
Time Delay
Enable or Disable
Event Types and Properties
Event Types
Main FAN Overload
Possible Event Notifications
Event notifications-large or small display
Calculation of Next Maintenance and Diagnostics
Next Maintenance Calculation
Calculating Unit Wellness
Parameters for Next Maintenance Calculation
General Maintenance Settings
Fans / Heaters / Humidifier Settings and Diagnostics
Compressor 1 / 2 Settings and Diagnostics
Teamwork Mode
Teamwork Modes
Application of Teamwork Modes
No Teamwork
Teamwork Mode 1 with two cooling units
Standby Rotation Typical Standby Lead/Lag Function
Standby and Cascade
U2U Hardware Cables and Network Switch
Placement of Cooling Units
Minimum Network Switch Requirements
Sample Liebert iCOM network configurations
Wiring for Unit-to-Unit Communications-U2U
Liebert iCOM U2U Ethernet Network
Wiring a Liebert iCOM U2U Network Small Displays
Large Displays
Wall-Mount Large Display
Combining Large and Small Displays on a U2U Network
Wiring a small display for stand-alone operation
Wiring a large display for stand-alone operation
Ports available for connecting Liebert iCOM control devices
Liebert vNSA
298 84mm 305mm 14.25 362mm DPN001136 Rev
Necessary Mounting Items
Location Considerations
Mounting Instructions
Liebert iCOM display dimensions
Spare Part List-Large Display Only
Setpoints parameters
Spare part list parameters-large display only
Event log parameters
Set alarms parameters
Sensor data
Active alarms parameters
Active Alarms
Display setup parameters
Timer parameters-Sleep Mode
Total run hours parameters
Service contacts parameters
Service Menu Parameters
Unit Diary-Large Display Only
Unit diary parameters
Standby settings / lead-lag parameters
Maintenance / wellness settings parameters
Wellness COMP2
Wellness HEAT2
Diagnostics / service mode parameters
ALM REL
7of
Delay
Enable Disab
Enable Disab Comp 1 Overload
Unit X Disconnected WRN Loss of Power LOP MSG, WRN, ALM
Call Service MSG, WRN, ALM High Temperature
Sensor calibration / setup parameters
System / network setup parameters-large display only
Network setup parameters
GBP
Static RAM Not Available, Invalid, OK
Options setup parameters
HUM Steam
Service contact info parameters
Service Menu Parameters
Service Menu Parameters
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