Trane CVGF-SVU02B-E4, CVGF 400, CVGF 1000 Operation And Maintenance Manual

Operation Maintenance Manual
Gear-Driven Centrifugal Water-Cooled Liquid Chillers with CH530 Controls
CVGF-SVU02B-E4
Unit Model CVGF 400-1000 Ton Units (50 and 60 Hz)
CVGF-SVU02B-E4
© 2005 American Standard Inc. All rights reserved.
Warnings and Cautions
Warnings and Cautions
Notice that warnings and cautions appear at appropriate intervals throughout this manual. Warnings are provided to alert installing contractors to potential hazards that could result in personal injury or death, while cautions are
designed to alert personnel to conditions that could result in equipment damage.
Your personal safety and the proper operation of this machine depend upon the strict observance of these precautions.
NOTICE: Warnings and Cautions appear at appropriate sections throughout this manual. Read these carefully.
WARNING – Indicates a potentially hazardous situation which, if not avoided, could result
in death or serious injury.
CAUTION – Indicates a potentially hazardous situation which, if not avoided, may result in
minor or moderate injury. It may also be used to alert against unsafe practices.
CAUTION – Indicates a situation that may result in equipment or property-damage-only
accidents.
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Contents
Warnings and Cautions
General Information
Unit Control Panel (UCP)
Base Loading Control Algorithm
Control System Components
Machine Protection and Adaptive
Unit Startup
Unit Shutdown
Periodic Maintenance
2
4
22
44
47
62
73
76
77
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Model Number
Refer to the Installation Manual.
Product Description Block
A typical Product Description Block is shown in the Installation Manual.
Unit Nameplate
The unit nameplate is located on the left side of the unit control panel.
Note: Trane starters are identified by a separate model number found on the starter.
Literature History
CVGF-SVU02A-E4 (November 2002)
This is a new manual.
About this manual
Operation and maintenance information for models CVGF are covered in this manual. This includes both 50 and 60 Hz. CVGF centrifugal chillers equipped with the Tracer CH530 Chiller Controller system.
Carefully review this information and follow the instructions given to successfully operate and maintain a CVGF unit.
If mechanical problems do occur, contact a qualified service organization to ensure proper diagnosis and repair of the unit.
General Information
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Commonly Used Abbreviations
For convenience, a number of abbreviations are used throughout this manual. These are listed alphabetically below, along with a translation of each:
ASME = American Society of Mechanical Engineers
ASHRAE = American Society of Heating, Refrigerating and Air Conditioning Engineers
BAS = Building Automation System
CDBS = Condenser Bundle Size
CDSZ = Condenser Shell Size
CH530 = Tracer CH530 Controller.
CWR = Chilled Water Reset
CWR’ = Chilled Water Reset Prime
DTFL = Design Delta-T at Full Load (for example, the difference between entering and leaving chilled water temperatures)
DV = DynaView
Clear Language Display, also know as the Main Processor (MP)
ELWT = Evaporator Leaving Water Temperature
ENT = Entering Chilled Water Temperature
EXOP = Extended Operation
GBAS = Generic Building Automation Interface
GPM = Gallons-per-minute
HLUV = High Lift Unloading Valve.
Hp = Horsepower
HVAC = Heating, Ventilating, and Air Conditioning
IE = Internally-Enhanced Tubes
IPC = Interprocessor Communication
LCD = Liquid Crystal Display
LED = Light Emitting Diode
General Information
LLID = Low Level Intelligent Device (Sensor, Pressure Transducer, or Input/output UCP module)
MAR = Machine Shutdown Auto Restart (Non-Latching where chiller will restart when condition corrects itself.)
MMR = Machine Shutdown Manual Restart (Latching where chiller must be manually reset.)
MP = Main Processor
PFCC = Power Factor Correction Capacitor
PID = Proportional Integral Derivative
PSID = Pounds-per-Square-Inch (differential pressure)
PSIG = Pounds-per-Square-Inch (gauge pressure)
ODT = Outdoor Temperature
OPST = Operating Status Control
RLA = Rated Load Amps
RTD = Resistive Temperature Device Tracer CH530= Controls Platform used on this Chiller
TRMM = Tracer Communications
UCP = Unit Control Panel
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Figure 2. Component location for typical CVGF unit (back view)
Motor
Unit nameplate
Relief valves
Oil cooler
Economizer
Condenser
Two-Stage Compressor
Unit-Mounted Starter (Optional)
Relief Valves
Unit Nameplate
Control Panel CH530
Oil Pump
Evaporator
General Information
Figure 1. General CVGF unit component
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Cooling Cycle
The refrigeration cycle of the CVGF chiller can be described using the pressure-enthalpy diagram shown in Figure 3. Key state points are indicated and will be referred to in the following discussion. A schematic of the system showing refrigerant flow is given in Figure 4.
Evaporator - A liquid vapor refrigerant mixture enters the evaporator at state point 1. Liquid refrigerant is vaporized to state point 2 as it absorbs heat from the system cooling load. The vaporized refrigerant flows into the compressor first stage.
Compressor first stage ­Refrigerant vapor is drawn from the evaporator into the first stage compressor. The first stage impeller accelerates the vapor increasing its temperature and pressure to state point 3.
General Information
Figure 3. P-H chart
P
Pc
P
1
Pe
5
8
1
RE
RE
1
Evaporator
Economizer
Condenser
4 Compressor 2nd stage
3 Compressor 1st stage
2
H
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Compressor second stage ­Refrigerant vapor leaving the first stage compressor is mixed with cooler refrigerant vapor from the economizer. This mixing lowers the enthalpy of the vapor entering the second stage. The second stage impeller accelerates the vapor, further increasing its temperature and pressure to state point 4.
Condenser - Refrigerant vapor enters the condenser where the system cooling load and heat of compression are rejected to the condenser water circuit. This heat rejection cools and condenses the refrigerant vapor to a liquid at state point 5.
Economizer and refrigerant orifice system - Liquid
refrigerant leaving the condenser at state point 5 flows through the first orifice and enters the economizer to flash a small amount of refrigerant at an intermediate pressure labeled P1. Flashing some liquid refrigerant cools the remaining liquid to state point 8.
Another benefit of flashing refrigerant is to increase the total evaporator Refrigeration Effect from RE’ to RE. The economizer provides around 4 percent energy savings compared to chillers with no economizer.
To complete the operating cycle, liquid refrigerant leaving the economizer at state point 8 flows through a second orifice. Here refrigerant pressure and temperature are reduced to evaporator conditions at state point 1.
An innovative design feature of the CVGF chiller is maximizing the evaporator heat transfer performance while minimizing refrigerant charge requirements. This is accomplished by the Trane-patented falling film evaporator design. The amount of refrigerant charge required in CVGF is less than that in comparably sized chillers of flooded evaporator design.
General Information
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General Information
Figure 4. Refrigerant flow diagram
Starter
Condenser
Motor
Economizer Oil sump
Pump
Fixed orifice
Distributor
Evaporator
Fixed orifice
Strainer
Fixed orifice
Condenser sump
Internal filter
Compressor
Inlet vanes
High lift unloading valve (HLUV)
Gears
Bearings
Oil cooler
Refrigerant Flow
S
F
ST
2
ST
1
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Compressor Description
The CVGF compressor consists of three distinct sections: the two-stage centrifugal compressor, the motor, and the gear box with integral oil sump. See Figure 5.
Compressor
The centrifugal compressor is two-stage with high-strength aluminum alloy fully shrouded impellers. The impellers are tested at 25 percent over design operating speed. The rotating assembly is dynamically balanced for vibration of less than 5.1 mm/sec (0.2 ips peak velocities) at nominal operating speeds. The control system affords 20 to 100 percent capacity modulation by electrically actuated guide vanes upstream of each impeller.
General Information
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General Information
Figure 5. Compressor cross-section view
Motor rotor
Motor shaft
Bull gear
Discharge end
Suction end
Motor terminal
Motor housing
Motor stator
Pinion shaft
Gear housing
2nd stage impeller
Oil pump
1st stage impeller
Oil sump
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Drive Train
The drive train consists of helical bull and pinion gears. Gear tooth surfaces are case hardened and precision ground. The one-piece impeller shaft is supported by hydrodynamic thrust and radial bearings.
Motor
The motor is a hermetic, liquid refrigerant cooled, two-pole, low-slip squirrel cage induction motor. A radial hydrodynamic bearing and duplex angular contact ball bearings support the rotor assembly. Winding­embedded sensors provide positive thermal protection.
Controls Overview
Controls Operator Interface
Information is tailored to operators, service technicians and owners. When operating a chiller, there is specific information you need on a day­to-day basis such as setpoints, limits, diagnostic information, and reports.
When servicing a chiller, you need different information and a lot more of it such as historic and active diagnostics, configuration settings, and customizable control algorithms, as well as operation settings.
By providing two different tools, one for daily operation and one for periodic service, appropriate information is readily accessible.
DynaView™Human Interface
For the operator, day-to-day operational information is presented at the panel. Up to seven lines of data (English or SI units) are simultaneously displayed on the touch-sensitive screen. Logically organized groups of information such as chiller modes of operation, active diagnostics, settings and reports put information conveniently at your fingertips. See Operator Interface Section for details.
TechView™ Chiller
For the service technician or advanced operator all chiller status, machine configuration settings, customizable limits, and up to 60 active or historic diagnostics are displayed through the TechView
interface. Using TechView™, a technician can interact with an individual device or a group of devices for advanced troubleshooting. LED lights and their respective TechView
indicators visually confirm the viability of each device. Any PC that meets the system requirements may download the service interface software and Tracer CH530 updates. For more information on TechView™visit your local Trane Service company, or The Trane Company’s website at www.trane.com.
General Information
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General Information
Figure 6. CVGF sequence of operation overview
Stopped
Stopped
Run Inhibit
Power Up
Stopping
Preparing to Shut
Down Shutting
Down
Starting
Auto
Waiting to Start
Starting
Compressor
Running
Running
Running - Limit
Fast Restart or Satisfied Setpoint
Stop Command or Diagnostic
Confirm
ed Shutdow
n
Confirm
ed Start
Stop Command
Diagnostic
Start Command
Diagnostic Reset
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General Information
Figure 7. Sequence of operation: power up
Apply
Control
Power
Completing Self Test
(12 Seconds)
Self Test
Starting Application
(20-30 Seconds*)
Starting
Application
*Note: The variation in DynaView Power Up time is dependent on the number of installed options.
Last Mode
Such as Auto or
Stopped
as shown
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General Information
Figure 8. Sequence of operation: running
Starter Status is “Running”
Limit Mode
Exit Limit Mode
Starting Compressor
Running
- Limit Running
Running
Modulate IGV for LWT control
Running
Modulate IGV for Limit control
Modulate IGV for LWT control
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Figure 9. Immediate shutdown to stopped or run inhibit
General Information
Running
Immediate shutdown non-latching diagnostic
Immediate shutdown latching diagnostic
Panic stop
Run Inhibit
Stopped
Post lube complete
Run Inhibit or Stopped
Post lube and evaporator pump off delay complete
Shutting down Shutting down Shutting down
Close IGV (0-50 seconds)
Post Lube: (1 minute)
De-energize oil pump
Confirm no oil pressure* 5 minutes after oil pump is de-energized
De-energize evaporator water pump relay
Evaporator pump off delay not performed for immediate shutdown
De-energize compressor
Confirm no compressor currents 8 seconds after compressor is de­energized
De-energize condenser water pump
*Note: No oil pressure when oil differential pressure switch is open.
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General Information
Figure 10. CVFG sequence of operation: satisfaction setpoint
Running
Preparing shutdown Shutting down Shutting down
*Note: No oil pressure when oil differential pressure switch is open.
Satisfied setpoint
Command IGV closed
De-energize compressor
Confirm no oil pressure* 5 minutes after oil pump is de-energized
De-energize oil pump
Close IGV (0-50 seconds)
Post lube (1 minute)
Auto
Confirm no compressor currents within 30 seconds
De-energize condenser water pump relay
Enforce all running mode diagnostics
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Oil Management
The primary purpose of Oil Management is to ensure appropriate and sufficient lubrication to the bearings during compressor operation and to minimize refrigerant dilution in the oil.
The Oil Management system performs safety checks and manages the operation of the Oil Pump and the Oil Heater. The sensor inputs used for these purposes are the Differential Oil Switch, and the Oil Temperature.
Two oil heater outputs exist, that should always operate simultaneously, for example, both on or both off.
Note: The Oil Pump and the Oil Heater are never energized at the same time.
Low Oil Temperature Start Inhibit Setpoint default is: 95° F.
When enhanced oil protection is enabled, the low oil temperature start inhibit is the saturated evaporator at 30°F (16.6°C) or 105°F (40.5°C), whichever is higher.
When enhanced oil temperature protection is enabled, the oil temperature setpoint is fixed at 136°F (57.8°C).
The oil temperature control setpoint range is settable from: 100 to 160°F (37.8 to 71.1°C)
Essential Modes
The Oil-Management has the following modes:
1. Low Temperature Start Inhibit:
The oil temperature is at or below the low oil temperature start inhibit setpoint. The heater is energized to raise the oil temperature. See Low Temperature Start Inhibit section for information about Enhanced Oil Temp Protection.
This mode is indicated to the user.
2. Idle: The oil pump is off. The oil temperature is maintained by the heater, at the control­temperature setpoint +/- 2.5°F (1.4°C).
3. Pre-lube: The oil pump lubricates the bearing for 30 seconds before the compressor starts.
This mode is indicated to the user.
4. Running: The oil pump continues to lubricate the bearings when the compressor is running.
General Information
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5. Post-lube: The oil pump lubricates the bearings for 60 seconds after the compressor is stopped to ensure bearings remain lubricated as the compressor coasts to a stop.
If a start command is issued while in post-lube, a quick restart will be performed.
The post-lube mode is indicated to the user on DynaView™and TechView™.
6. Manual: The oil pump can be commanded on and off in a manual mode.
Oil Temperature Control
The oil heater is used to maintain the oil temperature within +/- 2.5°F (4.5°C) of the oil temperature control setpoint. The oil heater is commanded off when the oil pump is commanded on.
Oil Differential Pressure Check
The Oil Differential Pressure Check validates the oil differential pressure before the oil pump is turned on. This check in necessary in case the differential pressure switch is not operational. Without this check, the differential oil pressure feedback is gone. This check is made after post-lube is complete to verify that the differential pressure has dropped to indicate no oil flow.
Here are the details:
CH530 verifies that the pressure switch is reading no differential pressure with the oil pump off before proceeding with pre-lube.
CH530 displays a mode Waiting for Low Oil Differential Press.
The check is made if oil pump is off and before it is turned on.
CH530 allows five minutes for the differential oil pressure switch to open.
This check is performed on power up or reset also. If a MPL occurred or power up was within the post-lube time, oil pump is running so do not do the check.
General Information
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Protective Diagnostics and their description
Differential Oil Pressure Overdue
is a latching diagnostic that can come up while the unit is in pre­lube.
The differential pressure switch status is used instead of the Low Differential Oil Pressure Cutout setpoint.
Low Differential Pressure Cutout
is a latching diagnostic that can come up while the unit is running. Oil pressure is indicative of oil flow and active oil pump operation. Significant fall in oil pressure is indicative of failure of the oil pump, oil leakage, or other blockage in the oil circuit.
Once oil flow has been established, if the differential pressure switch indicates there is not oil pressure for 2 seconds, this diagnostic will be issued.
Unexpected Differential Oil Pressure is a latching diagnostic
that can come up while the unit is idle and is implemented to recognize and ensure that the pressure switch is operational and that it is open for a period of five minutes.
General Information
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General Information
Figure 11. Oil circuit diagram
Starter
Condenser
Economizer
Condenser
Sump
High Lift
Unloading
Valve (HLUV)
Refrigerant
Oil
Motor
Oil Cooler
Strainer
S
F
Distributor
Evaporator
Fixed Orifice
Oil Sump
Pump
Internal Filter
Bearings
Gears
ST 1
ST 2
Compressor
Fixed Orifice
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Control Panel Devices and Unit Mounted Devices
Unit Control Panel (UCP)
Safety and operating controls are housed in the unit control panel, and the starter panel. The UCP ‘s operator interface and main processor is called the DynaView™and is located on the UCP door. (See Operators interface section for detailed information)
The UCP houses several other controls modules called panel mounted LLID (Low Level Intelligent Device), power supply, terminal block, fuse, circuit breakers, and transformer. The IPC (Interprocessor communication) bus allows the communications between LLID’s
and the main processor. Unit mounted devices are called frame mounted LLID’s and can be temperature sensors or pressure transducers. These and other functional switches provide analog and binary inputs to the control system.
Unit Control Panel (UCP)
Figure 12. Control panel
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Whenever the controller senses a situation that might trigger a protective shutdown, it focuses on bringing the critical parameter back into control. When the parameter is no longer critical, the controller switches its objective back to controlling the chilled water temperature, or to another more critical parameter should it exist.
Variable water flow through the evaporator
Chilled water systems that vary water flow through chiller evaporators have caught the attention of engineers, contractors, building owners, and operators. Varying the water flow reduces the energy consumed by pumps, while requiring no extra energy for the chiller. This strategy can be a significant source of energy savings, depending on the application. With its faster and more intelligent response to changing conditions, Tracer CH530 reliably accommodates variable evaporator water flow and its effect on the chilled water temperature. These improvements keep chilled water flowing at a temperature closer to its setpoint.
Unit Control Panel (UCP)
Tracer CH530 Chiller Controller
Tracer CH530’s Main Processor, DynaView™, is fast and keeps the chiller online whenever possible. Smart sensors collect three rounds of data per second, 55 times the data collection speed of its predecessor. Each device (a sensor) has its own microprocessor that simultaneously converts and accurately calibrates its own readings from analog to digital.
Because all devices are communicating digitally with the DynaView™, there is no need for the main processor to convert each analog signal one at a time. This distributed logic allows the main processor to focus on responding to changing conditions in the load, the machine, its ancillary equipment, or its power supply. Tracer CH530 constantly receives information about key data parameters, temperatures and currents. Every five seconds a multiple objective algorithm compares each parameter to its programmed limit. The chiller’s Adaptive Control™capabilities maintain overall system performance by keeping its peak efficiency.
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DynaView
presents three menu tabs across the top which are labeled “MAIN, REPORTS, and SETTINGS”.
The Main screen provides an overall high level chiller status so the operator can quickly understand the mode of operation of the chiller.
The Chiller Operating Mode will present a top level indication of the chiller mode (Auto, Running, Inhibit, Run Inhibit, and so forth) The “additional info” icon will present a subscreen that lists in further detail the subsystem modes.
The MP contains non-volatile memory both checking for valid set points and retaining them on any power loss. System data from modules (LLID) can be viewed at the DynaView
operator interface. Such as evaporator and condenser water temperatures, outdoor air temperature, evaporator and condenser water pump control, status and alarm relays, external auto-stop, emergency stop, and evaporator and condenser water flow switches.
Unit Control Panel (UCP)
The DynaView™(DV) Operator Interface contains the Main Processor (MP) which communicates commands to other modules, collecting data, status and diagnostic information from the other modules over the IPC (Inter Processor Communications) link. The Main Processor software controls water flows by starting pumps and sensing flow inputs, establishes a need to heat or cool, performs pre­lube, performs post-lube, starts the compressor, performs water temperature control, establishes limits, and pre-positions the inlet guide-vanes.
Figure 13. DynaView™main processor
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Unit Control Panel (UCP)
Main screen content can be viewed by selecting the up or down arrow icons. The Main screen is the default screen.After an idle time of 30 minutes.
DynaView™(DV) is the operator interface of the Tracer CH530 control system utilized on the CTV machines. The DynaView
enclosure is 9.75" (24.8 cm) wide, 8” (20.3 cm) high and 1.6” (4.1 cm) deep. The DynaView
display is approximately 4” (10.2 cm) wide by 3” (7.6) high. Features of the display include a touch screen and long life LED backlight. This device is capable of operating in 0 - 95 percent relative humidity (non­condensing). The enclosure includes a weather tight connection means for the RS232 TechView™connection.
Touch screen key functions are determined completely in the software and change depending upon the subject matter currently being displayed. The user operates the touch sensitive buttons by touching the button of choice. The selected button is darkened to indicate it is the selected choice. The advantage of touch sensitive buttons is that the full range of possible choices as well as the current choice is always in view.
Up or down arrow buttons are used to allow a continuously variable setpoint, such as leaving water setpoint. The value changes by touching the up or down arrows.
Action buttons are buttons that appear temporarily and provide the operator with a choice such as Enter or Cancel. The operator indicates his choice by touching the button of choice. The system then takes the appropriate action and the button typically disappears.
DynaView™consists of various screens, each meant to serve a unique purpose of the machine being served. Tabs are shown row across the top of the display. The user selects a screen of information by touching the appropriate tab. The folder that is selected will be brought to the front so it’s contents are visible
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Unit Control Panel (UCP)
The main body of the screen is used for description text, data, setpoints, or keys (touch sensitive areas) The double up arrows cause a page by page scroll either up or down. The single arrow causes a line by line scroll to occur. At the end of the screen, the appropriate scroll buttons will disappear.
The bottom of the screen is the persistent area. It is present in all screens and performs the following functions. The left circular area is used to reduce the contrast and viewing angle of the display. The right circular area is used to increase the contrast and viewing angle of the display. The contrast control will be limited to avoid complete “light” or complete “dark”, which would potentially confuse an unfamiliar user to thinking the display was malfunctioning.
Persistent keys, horizontal at the bottom of the display, are those keys that must be available for operation regardless of the screen currently being displayed. These keys are critical for machine operation. The Auto and Stop keys will be presented as radio buttons within the persistent key display area. The selected key will be dark. The chiller will stop when the Stop key is touched, entering the stop sequence. Pressing the “Immediate Stop” button will cause the chiller to stop right away.
The AUTO and STOP, take precedence over the ENTER and CANCEL keys. (While a setting is being changed, AUTO and STOP keys are recognized even if ENTER or CANCEL has not been pressed. Selecting the Auto key will enable the chiller for active cooling.
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The machine-operating mode indicates the operational status of the chiller. A subscreen with additional mode summary information will be provided. When the user scrolls down the screen the Machine Operation Mode will remain stationary
On DynaView™, the user will be presented with a single line of text that represents the ‘top­level’ operating state of the machine. These top-level modes are shown in the Table 1. Additional information (if it exists) regarding the machine operating state will be available to the user by selecting the “additional information” button (double right arrow) next to the top-level operating mode. These sub-level modes are shown Table 1.
The TOP LEVEL MODE is the text seen on the single top level chiller system operating mode line. The SUB LEVEL MODE is the text seen on the operating mode sub-menu. The operating mode sub-menu may have up to six (6) lines of text displayed.
The BAS CODE is the code that will be sent via COMM4/5 to the Tracer Summit system as the chiller system mode. Note that each top level mode may contain multiple sub level modes. In general, the BAS CODE will reflect the top level mode and not the sub level mode.
Unit Control Panel (UCP)
Figure 14.
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