Intelligent Communications & Monitoring System User Manual
Table Of Contents
- 1.0 Introduction
- 2.0 Liebert iCOM Display Components and Functions
- Figure 2 Liebert iCOM display components
- Table 1 Keyboard icons and functions
- Figure 3 Status menu, large display, graphical view
- Figure 4 Liebert iCOM default screen symbols
- 2.1 Navigating Through the Liebert iCOM Menus
- 3.0 Operation
- 3.1 Single Unit Functions
- 3.2 Motorized Ball Valve in Digital Scroll Units
- 3.3 Temperature Control—Single Source Cooling (No Extra Cooling Coil)
- 3.3.1 Temperature Proportional Band
- 3.3.2 Compressor Control
- Compressor Proportional Bands
- Figure 12 One single-step compressor without unloaders
- Figure 13 Two single-step compressors without unloaders or one compressor with an unloader (two-step)
- Figure 14 Two compressors with unloaders (four-step)
- Figure 15 Digital scroll capacity modulation, 10-100% variable
- Figure 16 Single and dual digital scroll compressor activation points
- Compressor Proportional Bands
- 3.3.3 Chilled Water Control
- 3.4 Temperature Control—Second Cooling Source
- 3.5 Temperature Control—Reheat
- 3.6 Humidity Control
- 3.7 Control Types
- 3.8 Possible Event Notifications
- 3.9 Next Maintenance Calculation
- 4.0 Teamwork
- 5.0 Installing a Liebert iCOM Unit-to-Unit Network
- 5.1 Placement of Cooling Units
- 5.2 U2U Hardware: Cables and Network Switch
- 5.3 Wiring for Unit-to-Unit Communications—U2U
- 5.4 External Communications—Building Management Systems, Liebert SiteScan®
- 6.0 Mounting a Large Display on a Wall
- 7.0 User Menu Parameters
- 8.0 Service Menu Parameters
- Table 23 Setpoints parameters
- Unit Diary—Large Display Only
- Table 24 Unit diary parameters
- Table 25 Standby settings / lead-lag parameters
- Table 26 Maintenance / wellness settings parameters
- Table 27 Diagnostics / service mode parameters
- Table 28 Set alarms parameters
- Table 29 Sensor calibration / setup parameters
- Table 30 System / network setup parameters—large display only
- Table 31 Network setup parameters
- Table 32 Options setup parameters
- Table 33 Service contact info parameters
Operation
18
3.3.2 Compressor Control
Depending on the type of Liebert air conditioning unit you have your unit may contain one or two
compressors with or without unloaders.
Compressor Proportional Bands
One Single-Step Compressor Without Unloaders—One-Step
One single-step compressor, Cool 1, is started at 100% call for cooling from the temperature propor-
tional band and stopped at 0% (see Figure 12).
Figure 12 One single-step compressor without unloaders
Two Single-Step Compressors Without Unloaders—Two-Step
First single-step compressor, Cool 1, is started at 50% calculated output from the temperature propor-
tional band, and stopped at 0%. The second compressor, Cool 2, starts at 100% and stops at 50% (see
Figure 13).
One Compressor With an Unloader—Two-Step
The two-step compressor is started unloaded at 50%, Cool 1, calculated output from the temperature
proportional band and stopped at 0%. At 100% the compressor starts fully loaded, Cool 2, and returns
to unload operation at 50% (see Figure 13).
Figure 13 Two single-step compressors without unloaders or one compressor with an unloader (two-step)
Temp Setpoint : 70°F
Proportional Band : 8°F
Deadband : 2°F
75
½ Proportional Band
0%
Cooling
+ 100 %
Cooling
71 72 73 7470
½ Dead-
band
Cool 1
Off
Cool 1
On
Increasing Temperature
Temp Setpoint : 70°F
Proportional Band: 8°F
Deadband : 2°F
75
1/2 Proportional Band
0%
Cooling
+ 100%
Cooling
71 72 73 7470
1/2 Dead-
band
Cool 1
On
Cool 2
On
Increasing Temperature
Cool 2
Off
Cool 1
Off