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Operation
3.3Temperature Control—Single Source Cooling (No Extra Cooling Coil)
3.3.1Temperature Proportional Band
The control uses the temperature proportional band to determine which operation to perform (cool- ing/heating) and how intensely to perform it. The Temperature Proportional Band is a user-defined range that is divided into two equal parts for cooling and heating. The Temperature Setpoint is between these two equal parts.
An optional Temperature Deadband range can be defined, which is equally divided on either side of the setpoint and separates the two halves of the proportional band. Figure 11 illustrates how the temperature proportional band is evenly divided on either side of the temperature setpoint, with and without a deadband.
Figure 11 Temperature proportional band
| | Without Deadband | |
- Temp | Heating | | Cooling | + Temp |
| ½ Proportional Band | | ½ Proportional Band + 100% |
| - 100% | 0% | |
| Heating | | Setpoint | Cooling | |
With Deadband
| | Dead- | | |
- Temp | Heating | band | Cooling | + Temp |
- 100% ½ Proportional Band | | | ½ Proportional Band + 100% |
| 0% | 0% | |
| Heating | Setpoint | Cooling | |
When the return air temperature deviates from the setpoint it begins to penetrate one of the propor- tional band halves, cooling or heating. If the return air temperature increases, the control calls for 0% (none) to 100% (full) cooling capacity based on how far the temperature penetrates the cooling portion of the proportional band. If the return air temperature decreases, the control calls for 0% (none) to - 100% (full) heating capacity based on how far the temperature penetrates the heating portion of the proportional band.
When the return air temperature reaches the end of the proportional band, either 100% or -100%, full cooling or full heating capacity is provided. No operation is performed when a 0% call is calculated. The control varies the call for cooling and heating in 1% increments as the return air temperature moves through the proportional band halves.
The deadband range is used to widen the setpoint. When the return air temperature falls within the deadband, the control operates the same as if the temperature equaled the setpoint exactly. This set- ting helps maximize component life by preventing excessive component cycling. The Temperature Proportional Band and Temperature Deadband parameters are in the Service menu under the Set- points submenu. The Temperature Setpoint parameter is in both the User Menu and Service Menu under Setpoints.
There is a parameter AutoSet Enable (Service Menu, Setpoints), which automatically sets the propor- tional bands for temperature and humidity, and both the integration time factors according to the type of unit (Chilled Water, single or double compressor), with influence of the selected Teamwork Mode. See 4.1 - Teamwork Modes for more on using this feature.
Liebert iCOM
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Table of Contents
Mounting a Large Display on a Wall
Installing a Liebert Icom UNIT-TO-UNITNETWORK
Teamwork
Figures
Tables
Large and Small Displays
Features
ESC
Icon Key Name Function
Keyboard icons and functions
Status menu, large display, graphical view
Navigating Through the Liebert iCOM Menus
Accessing Submenus
Accessing Submenus on Small Displays
Accessing Submenus on Large Displays
Menu tree-Small display, stand-alone or networked
Entering a Password
Advanced Menu Unit
Service Menu Unit
Status Menu System View Status Menu Unit 1 View User Menu
Advanced Menu Unit #
Service Menu Unit #
Viewing Multiple Units with a Networked Large Display
SET
User menu icons
Service menu icons
Unit/Fan Control Start Stop
Single Unit Functions
Autorestart
Loss of Power Alarm
Fan Alarm / Fan Protection Settings
VSD Setpoint VSD Fan Speed Setting
Pump Down
High Pressure Alarm
Compressor Sequencing
Digital Scroll High Temperature
Compressor Timing-Units With Two Compressors
MBV Operation After Compressor is Turned Off
Service Offset-Changing System Pressure Settings
Motorized Ball Valve in Digital Scroll Units
Temperature proportional band
Temperature Proportional Band
Two Single-Step Compressors Without Unloaders-Two-Step
Compressor Control
Compressor Proportional Bands
One Single-Step Compressor Without Unloaders-One-Step
Two compressors with unloaders four-step
Two Compressors With Unloaders-Four-Step
Digital scroll capacity modulation, 10-100% variable
Digital Scroll Compressors
Chilled Water Control
Temperature Control-Second Cooling Source
Differential Temperatures / Controls Comparator Circuit
Delta T Temperature Difference Between Room and Glycol
Second cooling source and compressorized cooling
Dual Cooling Source
Temperature Control-Reheat
Reheat configuration types
Glycool Cooling-Free-Cooling
Heat On ½ Dead Band 100%
Off ½ Proportional Band Decreasing Temperature
SCR Reheat
Tight Mode
Standard Mode
Humidification
Humidity Control
Humidification Dehumidification
External Humidifier Control-Optional
Humidification Infrared Humidifier
Parameters for infrared humidifier control
Dehumidification Compressor Quantity
Dehumidification With Comp settings
Dehumidification
Dehumidification Low Limit
Reheat During Dehumidification
Temperature and Humidity Control Types
Control Types
Humidity Sensor Reading Control Types
Supply Limit-Optional
High and Low, Temperature and Humidity Events
Customer inputs
User Inputs / Customer Inputs
Event Types
Time Delay
Enable or Disable
Event Types and Properties
Main FAN Overload
Event notifications-large or small display
Possible Event Notifications
Calculating Unit Wellness
Next Maintenance Calculation
Calculation of Next Maintenance and Diagnostics
Compressor 1 / 2 Settings and Diagnostics
Parameters for Next Maintenance Calculation
General Maintenance Settings
Fans / Heaters / Humidifier Settings and Diagnostics
No Teamwork
Teamwork Mode
Teamwork Modes
Application of Teamwork Modes
Teamwork Mode 1 with two cooling units
Standby and Cascade
Standby Rotation Typical Standby Lead/Lag Function
Minimum Network Switch Requirements
Placement of Cooling Units
U2U Hardware Cables and Network Switch
Liebert iCOM U2U Ethernet Network
Wiring for Unit-to-Unit Communications-U2U
Sample Liebert iCOM network configurations
Combining Large and Small Displays on a U2U Network
Wiring a Liebert iCOM U2U Network Small Displays
Large Displays
Wall-Mount Large Display
Wiring a small display for stand-alone operation
Wiring a large display for stand-alone operation
Liebert vNSA
Ports available for connecting Liebert iCOM control devices
298 84mm 305mm 14.25 362mm DPN001136 Rev
Mounting Instructions
Location Considerations
Necessary Mounting Items
Liebert iCOM display dimensions
Event log parameters
Spare Part List-Large Display Only
Setpoints parameters
Spare part list parameters-large display only
Sensor data
Set alarms parameters
Display setup parameters
Active Alarms
Active alarms parameters
Total run hours parameters
Timer parameters-Sleep Mode
Service contacts parameters
Service Menu Parameters
Unit diary parameters
Unit Diary-Large Display Only
Maintenance / wellness settings parameters
Standby settings / lead-lag 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
GBP
Network setup parameters
Static RAM Not Available, Invalid, OK
HUM Steam
Options setup parameters
Service contact info parameters
Service Menu Parameters
Service Menu Parameters
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