Emerson Liebert iCOM User manual

Large Systems
iCOM Microprocessor
Environmental Training and Service Manual
TM-10098: Rev. 05/27/08

iCOM Control Training and Service Manual
iCOM
Training & Service
Manual
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iCOM Controls Training and Service Manual
Disclaimer of Warranties and Limitations of
Liabilities
The authors and editors have taken every precaution to ensure accuracy and
completeness in this manual. The authors and editors make no expressed or
implied warranty of any kind with regard to the documentation in this manual.
Liebert Corporation assumes no responsibility, and disclaims all liability for
incidental or consequential damages resulting from the use of this information or
from errors or omissions. Liebert Corporation may make improvements and/or
changes in the product(s) described in this manual at any time. Information in this
manual is subject to change at any time and does not represent a commitment on
the part of Liebert Corporation.
Liebert® and the Liebert logo are registered trademarks of Liebert Corporation.
Emerson® and the Emerson logo are registered trademarks of Emerson Electric
Co.
Copyright © 2006 by Liebert Corporation
All rights reserved throughout the world.
Specifications subject to change without notice.
Printed in the United States of America
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iCOM Control Training and Service Manual
Table of Contents
Cha
p
ter 1: Tem
p
erature/Humidit
y
Control 6
Temperature Control Types 6
Proportional Control 6
Proportional + Integral (PI) Control 7
Proportional + Integral + Derivative (PID) Control 7
Intelligent Control 8
Temperature Control Operations and Charts 8
2 Stage Compressorized 8
4 Stage Compressorized Cooling 11
Optional Dual Compressor Digital Scroll Operation 15
Optional Glycool (Econ-O-Cycle) Cooling 17
Optional Dual Source Cooling 20
Optional Staged Electric Reheat 21
Humidity Control 24
Absolute (Predictive) Humidity Control 24
Relative Humidity Control 26
Humidifier Control Operations and Charts 26
Autoflush Control for Infrared Humidifier 28
Dehumidification Operation 30
1 Stage Dehumidification, Compressorized Operation 30
2 Stage Dehumidification, Compressorized Operation 31
Reheat During Dehumidification 34
Additional Programs 35
Next Maintenance Calculation 46
Shared Parameters 48
Networking and Functions 49
Teamwork 57
Unit Lead/Lag or Running/Standby Functions 58
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iCOM Controls Training and Service Manual
Cha
p
ter 2: Pro
g
rammin
g
Functions 62
Programming Functions 62
iCOM Display Components and Functions 63
iCOM Keypad Layout Descriptions 64
iCOM Display Symbols / Icons 65
Programming Functions 66
Status Display Screens 67
Menu Screens and Symbols 69
User Menu Icons and Descriptions 70
Service Menu Icons and Descriptions 71
Advanced Menu Icons and Descriptions 72
Navigating and Accessing Sub Menus 72
Where and When to Save 73
User Menu Parameters 75
Service Menu Parameters 82
Advanced Menu Parameters 112
Cha
p
ter 3: iC
OM
Hardware Connections 131
Introduction 131
Display Assemblies 132
Unit Control Board DIP Switches and Jumpers 133
Small Display DIP Switches 135
Large Display DIP Switches and Jumpers 136
Temperature/Humidity Board DIP Switches and Jumpers 137
Unit Control Board Plug Connectors 138
Fuse Board Connectors 143
Temperature/Humidity Board Connectors 144
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iCOM Control Training and Service Manual
Cha
p
ter 4: General Troubleshootin
g
Data 146
Introduction 146
Isolation 147
Basic Operation of the Triac 148
Basic Operation of the Opto-Isolator 150
Troubleshooting the Opto-Isolator 151
Unit Control Board: Opto-Isolator/Triac Legends 153
Control Input Check (Aquastat Sensor) 155
iCOM Diagnostics/Service Mode Programs 156
Troubleshooting Checklist 157
Basic Troubleshooting Steps 158
Moisture Content Charts 160
Suction Transducer Information 177
Digital Scroll High Temperature Sensor Chart 178
Unit Code Configuration and Code Definitions 179
Glossar
y
of Terms 189
Com
p
uter and Network Terms 193
Network Information 198
How To Use The Schematic 200
Electrical Schematic List 201
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iCOM Controls Training and Service Manual
Chapter 1
Temperature and Humidity Control Programs
This section provides details on how your Liebert iCOM control responds to the
user programmed inputs values and room conditions. Refer to this section when
you need specific information on the controls operation. This section provides
details on the four (4) user selectable temperature control programs and the three
(3) user selectable humidity control programs.
Cooling and/or Heating Required, in Percent (%)
The temperature control programs for the iCOM microprocessor are based on a
calculated percent (%) requirement for cooling and/ or heating. This percent (%)
requirement is determined by the control type (algorithm) selected by the user.
The four (4) user selectable temperature control programs are:
•Proportional (P)
•Proportional + Integral (PI)
•Proportional + Integral + Derivate (PID)
•Intelligent
Temperature Control Types
Proportional (P) Control
The proportional control is the standard control method that maintains the room at
a temperature proportional to the load. The temperature maintained increases as
the room load increases. At full load the room would be controlled at a
temperature equal to the temperature set point (TSP) plus ½ of the temperature
proportional band (PB). The operator programmed inputs are the temperature set
point (TSP) and temperature proportional band (PB) adjustments. The operator
may also program a temperature dead band (DB) adjustment which will provide an
offset when the cooling or heating is activated or deactivated.
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iCOM Control Training and Service Manual
Proportional + Integral (PI) Control
The PI control combines two (2) individual terms to determine the control output
for a given set of conditions.
The proportional (P) term is determined by the difference between the current
temperature and the control set point. This term is expressed in % cooling
(heating) desired for each degree above (below) the set point. It is adjustable from
0% to 100% per degree. The purpose of this term is to adjust the control output
for any deviation between the current temperature and the control set point.
The integral (I) term is determined by two things: the difference between the return
air temperature and control set point and the amount of time this difference has
existed. This term is expressed in % cooling (heating) desired for each minute
and degree above (below) the set point. It is adjustable from 0% - 100% per
degree/minute. The purpose of this term is to force the control to maintain the
temperature around the set point by slowly but continuously adding (subtracting) a
small amount of cooling (heating) to the total control output until the temperature is
at the set point.
Proportional + Integral + Derivate (PID) Control
The PID control combines three individual terms to determine the control output for
a given set of conditions. Note that PID control is used only for temperature. If
PID control is selected, humidity will continue to use proportional control.
The proportional (P) term is determined by the difference between the current
temperature and the control set point. This term is expressed in % cooling
(heating desired for each degree above (below) the set point. It is adjustable from
0% to 100% per degree. The purpose of this term is to adjust the control output
for any deviation between the current temperature and the control set point.
The integral (I) term is determined by two things: the difference between the return
air temperature and control set point and the amount of time this difference has
existed. This term is expressed in % cooling (heating) desired for each minute
and degree above (below) the set point. It is adjustable from 0% - 100% per
degree/minute. The purpose of this term is to force the control to maintain the
temperature around the set point by slowly but continuously adding (subtracting) a
small amount of cooling (heating) to the total control output until the temperature is
at the set point.
The derivative (D) term is determined by the rate of change of temperature. This
term is expressed in % cooling (heating) desired for each degree per minute rise
(fall) in temperature. It is adjustable from 0% to 100% per degree/minute. The
purpose of this term is to adjust the control output for quickly changing
temperatures, thus providing an anticipation control.
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iCOM Controls Training and Service Manual
Intelligent Control
The Intelligent Control operates from a set of general rules that define how the
control output should be adjusted for different system conditions. The rules are
designed to duplicate the actions that an experienced human operator would take
if manually controlling the system.
Basically, this is done in a three-function process that differs from earlier
mathematical defined strict type data, hence, fuzzy logic. The on and off, true or
untrue type of statement is not used. The consideration now is how to set the
input value into a membership set, qualify this membership with rules, then decide
on the output consequence for action. It is not really that simple, but it is basically
how it works.
Temperature Control Operations and Charts
The temperature proportional control band value is divided into two parts: the
temperature set point plus ½ of the temperature proportional band for cooling
operation and the temperature set point minus ½ of the temperature proportional
band for heating operation.
A temperature dead band can also be programmed into the control to shift the
cooling and/ or heating on/ off operations away from the temperature set point.
This programmed temperature dead band value is divided into two parts: the
temperature set point plus ½ of the dead band – no cooling operation and the
temperature set point minus ½ of the band – no heating operation.
The temperature set point range is adjustable from 41 - 104°F in increments of
1°F. The temperature proportional band range is adjustable from 2 - 54°F in
increments of 1°F. The temperature dead band range is adjustable from 0 - 36°F
in increments of 1°F.
Standard 2 Stage Compressorized Cooling
The basic temperature cooling control band is established at the temperature set
point with the length equal to ½ of the programmed temperature proportional band
divided by the number of cooling stages.
Liebert DS units are supplied with two (2) compressorized cooling circuits. Each
compressor circuit is rated at ½ of the unit total cooling capacity. The two (2)
compressors can be either semi-hermetic or scroll type and will operate in an
on/off configuration to cool the space.
The temperature controller activates the first cooling stage (lead compressor)
when the return air temperature increases to 50% of the cooling proportional band
and the second cooling stage (lag compressor) at 100% of the cooling proportional
band.
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iCOM Control Training and Service Manual
The temperature controller deactivates the second stage of cooling (lag
compressor) when the return air temperature decreases to 50% of the cooling
proportional control band value. The first cooling stage (lead compressor) is
deactivated when the return air temperature decreases to the temperature set
point value or 0% of the cooling proportional control band value.
2 Stage Compressorized Cooling – No Dead Band
In the above example the control band begins at the 70°F temperature set point
and has a length of 4°F, which is ½ of the programmed temperature proportional
band value.
As the return air temperature increases, Cooling 1 (lead compressor) is activated
at 72°F or 50% of the cooling control band. If the return air temperature continues
to increase, Cooling 2 (lag compressor) will activate at 74°F or 100% of the cooling
control band.
When the return air temperature starts to decrease, Cooling 2 (lag compressor) is
deactivated at 72°F or 50% of the cooling control band and Cooling 1 (lead
compressor) is deactivated at the temperature set point of 70°F or 0% of the
cooling control band.
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iCOM Controls Training and Service Manual
In the example below the control band begins at the 70°F temperature set point
and has a length of 4.5°F, which is ½ of the programmed temperature dead band
value plus ½ of the programmed temperature proportional band value.
As the return air temperature increases, Cooling 1 (lead compressor) is activated
at 72.5°F or ½ of the dead band value plus 50% of the cooling control band. If the
return air temperature continues to increase, Cooling 2 (lag compressor) will
activate at 74.5°F or ½ of the dead band value plus 100% of the cooling control
band.
When the return air temperature starts to decrease, Cooling 2 (lag compressor) is
deactivated at 72.5°F or ½ of the dead band value plus 50% of the cooling control
band and Cooling 1 (lead compressor) is deactivated at 70.5°F or ½ of the dead
band value plus 0% of the cooling control band.
2 Stage Compressorized Cooling – With Dead Band
Remember the temperature dead band value is used by the control to shift
the cooling on/off operations away from the temperature set point.
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iCOM Control Training and Service Manual
Optional 4 - Step Cooling, Two (2) Compressors with Unloaders
The basic temperature cooling control band is established at the temperature set
point with the length equal to ½ of the programmed temperature proportional band
divided by the number of cooling stages.
Liebert DS units are supplied with two (2) compressorized cooling circuits. Each
compressor circuit is rated at ½ of the unit total cooling capacity. The two (2)
semi-hermetic type compressors are each supplied with an electrically controlled
suction cut-off cylinder unloader valve. The electrical solenoid valve is used to
unload or reduce the cooling capacity of the compressor. The compressors will
operate in an on/off - loaded/unloaded configuration method to cool the space.
Hot gas bypass option is not available on 4-stage cooling units.
Stage Activation on Temperature Increase
The temperature controller activates the first cooling step (lead compressor
unloaded) when the return air temperature increases to 33% of the cooling
proportional band. The second cooling step (lag compressor unloaded) is
activated when the return air temperature increases to 63% of the cooling
proportional band.
The temperature controller deactivates the unloader for the third cooling step (lead
compressor loaded) when the return air temperature increases to 80% of the
cooling proportional band. The temperature controller deactivates the unloader for
the fourth cooling step (lag compressor loaded) when the return air temperature
increases to 100% of the cooling proportional band.
Stage Deactivation on Temperature Decrease
The temperature controller activates the unloader on the lag compressor when the
return air temperature decreases to 90% of the cooling proportional control band
value. The unloader on the lead compressor activates when the return air
temperature decreases to 70% of the cooling proportional control band value.
The temperature controller deactivates the unloaded lag compressor when the
return air temperature decreases to 47% of the cooling proportional control band
value. The unloaded lead compressor is deactivated when the return air
temperature decreases to the temperature set point value of 17% of the cooling
proportional control band value.
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iCOM Controls Training and Service Manual
The table below shows the sequence of device operation by each of the four (4)
cooling stages.
STAGE COMPRESSORS, UNLOADER STATE
1 Compressor 1 On, Unloader On (Energized)
Compressor 2 Off, Unloader Off (De-Energized)
2 Compressor 1 On, Unloader On (Energized)
Compressor 2 On, Unloader On (Energized)
3 Compressor 1 On, Unloader Off (De-Energized)
Compressor 2 On, Unloader On (Energized)
4 Compressor 1 On, Unloader Off (De-Energized)
Compressor 2 On, Unloader Off (De-Energized)
The table below is based on a temperature set point of 70°F with a control band
length of 4°F, which is ½ of the programmed temperature proportional band value.
This example does not include a dead band value. The temperatures displayed
are approximate values as calculated by the microprocessor control.
STAGE TEMPERATURE
Cool 1 ON Set point plus 1.3°F = 71.3°F
Cool 2 ON Set point plus 2.5°F = 72.5°F
Cool 3 ON Set point plus 3.2°F = 73.2°F
Cool 4 ON Set point plus 4.0°F = 74.0°F
Cool 4 OFF Set point plus 3.6°F = 73.6°F
Cool 3 OFF Set point plus 2.8°F = 72.8°F
Cool 2 OFF Set point plus 1.9°F = 71.9°F
Cool 1 OFF Set point plus 0.7°F = 70.7°F
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iCOM Control Training and Service Manual
The example below is based on a temperature set point of 70°F with a control
band length of 4°F, which is ½ of the programmed temperature proportional band
value.
4-Step Compressorized Cooling w/No Dead Band
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iCOM Controls Training and Service Manual
The example below is based on a temperature set point of 70°F with a control
band length of 4°F, which is ½ of the programmed temperature proportional band
value, plus a ½ °F Deadband, which is ½ the programmed temperature deadband.
4 Stage Compressorized Cooling – With Dead Band
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iCOM Control Training and Service Manual
In the above example that the control band begins at the 70°F temperature set
point and has a length of 5°F, which is ½ of the programmed temperature dead
band value plus ½ of the programmed temperature proportional band value.
As the return air temperature increases Cooling 1 (lead compressor unloaded) is
activated at 71.8°F or ½ of the dead band value plus 33% of the cooling control
band. If the return air temperature continues to increase Cooling 2 (lag
compressor unloaded) will activate at 73.0°F or ½ of the dead band value plus
63% of the cooling control band. If the return air temperature continues to
increase Cooling 3 (lead compressor unloaded) is activated at 73.7°F or ½ of the
dead band value plus 80% of the cooling control band. If the return air
temperature continues to increase Cooling 4 (lag compressor loaded) will activate
at 74.5°F or ½ of the dead band value plus 100% of the cooling control band.
When the return air temperature starts to decrease, Cooling 4 is deactivated at
74.1°F or ½ of the dead band value plus 90% of the cooling control band. If the
return air temperature continues to decrease, Cooling 3 will be deactivated at
73.3°F or ½ of the dead band value plus 70% of the cooling control band. If the
return air temperature continues to decrease, Cooling 2 will be deactivate at
72.4°F or ½ of the dead band value plus 47% of the cooling control band and
Cooling 1 is deactivated at 71.2°F or 1/2 the dead band value plus 17% of the
cooling control band.
Remember the temperature dead band value is used by the control to shift
the cooling on/off operations away from the temperature set point.
Optional Dual Compressor Digital Scroll Operation
The optional Digital Scroll compressors operate in two stages, the “loaded state”
and the unloaded state”. During the loaded state the solenoid valve is de-
energized (closed) and the compressor operates like a standard scroll and delivers
full capacity. During the unloaded state the solenoid valve is energized (opened)
and the scroll plates are separated so there is no capacity through the
compressor.
Capacity modulation is achieved by energizing and de-energizing the solenoid
valve. Therefore, the cooling capacity achieved is the time average capacity
which is a variable from 10 – 100%. Example: If you have a 15 second cycle and
the solenoid is de-energized for 10 seconds, and then energized for 5 seconds,
the resulting capacity will be 66%. The factory default Digital Scroll Cycle time is
programmed at 15 seconds.
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iCOM Controls Training and Service Manual
In the chart below we are defining the Digital Compressor start and stop at the
sensible cooling capacity and how the compressors load and unload with the
PWM (Pulse Width Modulation) from the controller and the unit setting for
temperature control.
Note: The Digital Scroll will run continuously while the scroll plate is raised
and lowered as the need for cooling is required from 10% to 100% and vise
versa.
Digital Scroll PWM Cooling Control
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iCOM Control Training and Service Manual
Optional Glycool (Econ-O-Cycle) Cooling
When Liebert DS units are supplied with the Glycool option, the basic unit is
supplied with an additional coil, piping, valve and an Aquastat Sensor (AQ) which
measures the glycol fluid temperature. The sensor is mounted to the unit supply
fluid line and serves as the control interface in determining the system operation.
Selection between glycool or compressorized operation is controlled by the
microprocessor using this aquastat to sense the glycol temperature.
The Glycool Cooling program establishes two distinct control bands for cooling
control operation. The first band controls the operation of the chilled glycol valve
and the second controls the operation of the compressors, 2 stages, 4 stages or
digital scroll.
The microprocessor checks the return air temperature and the entering glycol fluid
temperature to determine a cooling capacity. In order to reduce compressor
cycling and to prevent chilled glycol valve hunting, Glycool cooling capacity does
not become available until the entering chilled glycol fluid temperature is at least
8°F below the return air temperature or 3°F lower than the return air temperature
for two (2) consecutive hours.
When the microprocessor decides that the return glycol fluid temperature is cold
enough the first cooling band is modulating valve control. A second band is added
to the first band for the compressors as in the normal 2 stage, 4 stage or digital
scroll control method. If the chilled glycol fluid temperature is not cold enough the
valve control band is replaced by the compressor band. If the chilled glycol
cooling capacity is reduced by a rise in the glycol fluid temperature, the control
band shrinks proportionally. This allows the compressor band to move down as
well. The following charts on the next two pages show the Glycool operation at
100% capacity and the Glycool at 50% capacity.
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iCOM Controls Training and Service Manual
Glycool at 100% Capacity – No Dead Band
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iCOM Control Training and Service Manual
Glycool at 50% Capacity – No Dead Band
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