Trane Sintesis RTAF-SVX002D-EN Installation and operating instructions

Sintesis™ Air-Cooled Chillers
Model RTAF, 500 Tons
Middle East Applications Only
Supplement to RTAF-SVX001*-EN
Installation, Operation, and Maintenance
April 2022 RTAF-SVX002D-EN
SAFETY WARNING
Only qualified personnel should install and service the equipment. The installation, starting up, and servicing of
heating, ventilating, and air-conditioning equipment can be hazardous and requires specific knowledge and training.
Improperly installed, adjusted or altered equipment by an unqualified person could result in death or serious injury.
When working on the equipment, observe all precautions in the literature and on the tags, stickers, and labels that are
attached to the equipment.

©2022 Trane RTAF-SVX002D-EN
Introduction
Read this manual thoroughly before operating or
servicing this unit.
Warnings, Cautions, and Notices
Safety advisories appear throughout this manual as
required. Your personal safety and the proper operation of
this machine depend upon the strict observance of these
precautions.
Important Environmental Concerns
Scientific research has shown that certain man-made
chemicals can affect the earth’s naturally occurring
stratospheric ozone layer when released to the
atmosphere. In particular, several of the identified
chemicals that may affect the ozone layer are refrigerants
that contain Chlorine, Fluorine and Carbon (CFCs) and
those containing Hydrogen, Chlorine, Fluorine and
Carbon (HCFCs). Not all refrigerants containing these
compounds have the same potential impact to the
environment. Trane advocates the responsible handling
of all refrigerants-including industry replacements for
CFCs and HCFCs such as saturated or unsaturated HFCs
and HCFCs.
Important Responsible Refrigerant
Practices
Trane believes that responsible refrigerant practices are
important to the environment, our customers, and the air
conditioning industry. All technicians who handle
refrigerants must be certified according to local rules. For
the USA, the Federal Clean Air Act (Section 608) sets forth
the requirements for handling, reclaiming, recovering and
recycling of certain refrigerants and the equipment that is
used in these service procedures. In addition, some states
or municipalities may have additional requirements that
must also be adhered to for responsible management of
refrigerants. Know the applicable laws and follow them.
The three types of advisories are defined as follows:
WARNING Indicates a potentially hazardous
situation which, if not avoided, could
result in death or serious injury.
CAUTIONsIndicates a potentially hazardous
situation which, if not avoided, could
result in minor or moderate injury. It
could also be used to alert against
unsafe practices.
NOTICE Indicates a situation that could result in
equipment or property-damage only
accidents.
WARNING
Proper Field Wiring and Grounding
Required!
Failure to follow code could result in death or serious
injury. All field wiring MUST be performed by qualified
personnel. Improperly installed and grounded field
wiring poses FIRE and ELECTROCUTION hazards. To
avoid these hazards, you MUST follow requirements
for field wiring installation and grounding as described
in NEC and your local/state/national electrical codes.
WARNING
Personal Protective Equipment (PPE)
Required!
Failure to wear proper PPE for the job being undertaken
could result in death or serious injury. Technicians, in
order to protect themselves from potential electrical,
mechanical, and chemical hazards, MUST follow
precautions in this manual and on the tags, stickers,
and labels, as well as the instructions below:
• Before installing/servicing this unit, technicians
MUST put on all PPE required for the work being
undertaken (Examples; cut resistant gloves/sleeves,
butyl gloves, safety glasses, hard hat/bump cap, fall
protection, electrical PPE and arc flash clothing).
ALWAYS refer to appropriate Safety Data Sheets
(SDS) and OSHA guidelines for proper PPE.
• When working with or around hazardous chemicals,
ALWAYS refer to the appropriate SDS and OSHA/
GHS (Global Harmonized System of Classification
and Labeling of Chemicals) guidelines for
information on allowable personal exposure levels,
proper respiratory protection and handling
instructions.
• If there is a risk of energized electrical contact, arc, or
flash, technicians MUST put on all PPE in accordance
with OSHA, NFPA 70E, or other country-specific
requirements for arc flash protection, PRIOR to
servicing the unit. NEVER PERFORM ANY
SWITCHING, DISCONNECTING, OR VOLTAGE
TESTING WITHOUT PROPER ELECTRICAL PPE AND
ARC FLASH CLOTHING. ENSURE ELECTRICAL
METERS AND EQUIPMENT ARE PROPERLY RATED
FOR INTENDED VOLTAGE.

Introduction
RTAF-SVX002D-EN 3
Factory Warranty Information
Compliance with the following is required to preserve the
factory warranty:
All Unit Installations
Startup MUST be performed by Trane, or an authorized
agent of Trane, to VALIDATE this WARRANTY. Contractor
must provide a two-week startup notification to Trane (or
an agent of Trane specifically authorized to perform
startup).
Copyright
This document and the information in it are the property of
Trane, and may not be used or reproduced in whole or in
part without written permission. Trane reserves the right
to revise this publication at any time, and to make changes
to its content without obligation to notify any person of
such revision or change.
Trademarks
All trademarks referenced in this document are the
trademarks of their respective owners.
Revision History
• Updated Start-Up chapter.
• Updated Wiring chapter.
WARNING
Follow EHS Policies!
Failure to follow instructions below could result in
death or serious injury.
• All Trane personnel must follow the company’s
Environmental, Health and Safety (EHS) policies
when performing work such as hot work, electrical,
fall protection, lockout/tagout, refrigerant handling,
etc. Where local regulations are more stringent than
these policies, those regulations supersede these
policies.
• Non-Trane personnel should always follow local
regulations.
WARNING
Refrigerant under High Pressure!
Failure to follow instructions below could result in an
explosion which could result in death or serious injury
or equipment damage. System contains refrigerant
under high pressure. Recover refrigerant to relieve
pressure before opening the system. See unit
nameplate for refrigerant type. Do not use non-
approved refrigerants, refrigerant substitutes, or
refrigerant additives.

4RTAF-SVX002D-EN
Table of Contents
Model Number Descriptions . . . . . . . . . . . . . . 5
General Information . . . . . . . . . . . . . . . . . . . . . 6
General Data . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Operating Principles . . . . . . . . . . . . . . . . . . . . . 7
Circuit Schematic . . . . . . . . . . . . . . . . . . . . . . 7
Economizer . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Start-Up and Shutdown . . . . . . . . . . . . . . . . . 10
Unit Start-Up . . . . . . . . . . . . . . . . . . . . . . . . . 10
Temporary Shutdown And Restart . . . . . . 10
Extended Shutdown Procedure . . . . . . . . . 10
Seasonal Unit Start-Up Procedure . . . . . . 11
System Restart After Extended Shutdown 11
Sequence of Operation . . . . . . . . . . . . . . . . 12
Software Operation Overview . . . . . . . . . 12
Timelines . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Power Up Diagram . . . . . . . . . . . . . . . . . . 13
Power Up to Starting . . . . . . . . . . . . . . . . 14
Stopped to Starting . . . . . . . . . . . . . . . . . 15
Running (Lead Compressor/Circuit Start and
Run) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Running (Lag Compressor/Circuit Start and
Run) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Satisfied Setpoint . . . . . . . . . . . . . . . . . . . 18
Unloading Unstaging . . . . . . . . . . . . . . . . 19
Normal Shutdown to Stopped or Run Inhibit
20
Immediate Shutdown to Stopped or Run In-
hibit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Ice Making (Running to Ice Making to Run-
ning) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Ice Making (Auto to Ice Making to Ice Making
Complete) . . . . . . . . . . . . . . . . . . . . . . . . . 23
Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Main Processor Diagnostics . . . . . . . . . . . . 25
Communication Diagnostics . . . . . . . . . . . 25
Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

RTAF-SVX002D-EN 5
Model Number Descriptions
Digits 1, 2 — Unit Model
RT = Rotary Chiller
Digit 3 — Unit Type
A= Air-cooled
Digit 4 — Development
Sequence
F = Development Sequence
Digits 5-7 — Nominal Capacity
500 = 500 Nominal Tons
Digit 8— Unit Voltage
C = 380/60/3
G = 400/60/3
Digit 9 — Manufacturing
Location
U = Trane Commercial Systems,
Pueblo, CO USA
Digits 10, 11— Design Sequence
** = Factory assigned
Digit 12 — Unit Efficiency
H = High Efficiency
Digit 13— Unit Sound Package
X = Standard Noise
Digit 14 — Agency Listing
U = UL/CUL Listing
Digit 15 — Pressure Vessel Code
A = ASME Pressure Vessel Code
Digit 16 — Factory Charge
2 = Refrigerant Charge R-134a
4=NitrogenCharge
(R-134a Field Supplied)
Digit 17 — Evaporator
Application
N = Standard Cooling
(above 40°F/5.5°C)
Digit 18 — Evaporator
Configuration
1 = 1-pass Evaporator
R = 1-pass Evaporator
with Turbulators
Digit 19 — Evaporator Fluid Type
1 = Water
2 = Calcium Chloride
3 = Ethylene Glycol
4 = Propylene Glycol
5 = Methanol
Digit 20 — Water Connection
X = Grooved Pipe Connection
W = Grooved Pipe + Flange
Digit 21 — Flow Switch
1 = Factory Installed - Other Fluid
15 cm/s
3 = Factory Installed - Water
45 cm/s
Digit 22 — Insulation
Note: N= Factory Insulation
All Cold Parts 0.75”
Digit 23 — Unit Application
H = High Ambient
(32 to 130°F/0 to 54.4°C)
Digit 24 — Condenser Fin
Options
N = Aluminum Microchannel
Digit 25 — Fan Type
X = Fixed Speed Fans
Digit 26 — Auxiliary Items
B = Oil Cooler and Economizer
Digit 27 — Compressor Starter
W = Wye-Delta Starter
Digit 28 — Incoming Power Line
Connection
2 = Dual Point Unit Power
Connection
Digit 29 — Power Line
Connection Type
C = Circuit Breaker
Digit 30— Short Circuit Current
Rating
A = Default Short Circuit Rating
Digit 31 — Electrical Accessories
X = No Convenience Outlet
Digit 32 — Remote
Communication Options
X= None
B = BACnet® Interface
M = Modbus™ Interface
L = LonTalk®Interface
Digit 33 — Hard Wire
Communication
X= None
A = Hard Wired Bundle - All
B = Remote Leaving Water Temp
Setpoint
C = Remote Leaving Temp and
Demand Limit Setpoints
D = Programmable Relay
E = Programmable Relay and
Leaving Water and Demand
Limit Setpoint
F = Percent Capacity
G = Percent Capacity and Leaving
Water and Demand Limit
Setpoint
H = Percent Capacity and
Programmable Relay
Digit 34 — Energy Meter
X= None
Digit 35 — Smart Flow Control
X= None
Digit 36 — Structural Options
A = Standard Unit Structure
Digit 37 — Appearance Options
X = No Appearance Options
Digit 38 — Unit Isolation
X= None
1 = Elastomeric Isolators
Digit 39 — Shipping Package
X = No Shipping Package
T = Shipped with Tarp Covering
Full Unit
Digits 40-42
XXX= Reserved for future use
Digit 43 — Special Requirement
0=None
S = Special Requirement

6RTAF-SVX002D-EN
General Information
This manual is a supplement to Sintesis™ RTAF
Installation, Operation, and Maintenance Manual
RTAF-SVX001*-EN, and provides information on the RTAF
configuration specifically designed for Middle East
applications. Not all options listed in RTAF IOM
RTAF-SVX001*-EN are available for this configuration.
General Data
Table 1. General data — 500 tons unit, middle east configuration
Compressor Model (ckt 1/ckt 2)(a) 120-120/120-120
Quantity # 4
Evaporator
Water Connection Size in 8
Passes # 1
Water Storage gal (L) 46.1 (174.7)
Minimum Flow gpm (l/s) 506 (31.9)
Maximum Flow gpm (l/s) 1855 (117.1)
Condenser
Qty of Coils (ckt 1/ckt 2) 14/14
Coil Length in (mm) 77.4 (1967)
Coil Height in (mm) 47.8 (1214)
Condenser Fans
Fan Type Fixed
Quantity (ckt 1/ckt 2) # 14/14
Diameter in (mm) 31.5 (800)
Nominal Speed rpm 1030
Airflow cfm (m3/sec) 11800 (5.6)
Tip Speed ft/min (m/s) 8493 (43.1)
Ambient Temperature Range
High Ambient °F (°C) 32 to 130 (0 to 54.4)
General Unit
Refrigerant Ckts # 2
Minimum Load % 15
Refrigerant R-134a
Refrigerant Charge (ckt 1/ckt 2) lbs (kg) 310.6/323.3 (140.9/146.6)
Oil Trane Oil 00311 (bulk)/OIL00315 (1 gal)/OIL00317 (5 gal)
Oil Charge (ckt 1/ckt 2) gal (L) 4.33/4.37 (16.4/16.5)
(a) Nominal tonnage at 60 Hz. Where there are 2 compressors on a circuit, they are indicated 1A-1B/2A-2B.

RTAF-SVX002D-EN 7
Operating Principles
Circuit Schematic
Figure 1. Schematic, refrigerant and oil systems — RTAF middle east configuration

Operating Principles
8RTAF-SVX002D-EN
Table 2. Legend
No Description No Description No Description
1 Screw Compressor 11 Electronic Expansion Valve PT Pressure Transducer
2 Evaporator 12 Sight Glass PSH High Pressure Relief Valve
3 Air-Cooled Condenser 13 Relief Valve PSL Low Pressure Relief Valve
4 Evaporator Water Inlet Connection 14 Service Valve PZH High Pressure Switch
5 Evaporator Water Outlet Connection 15 Solenoid Valve TT Temperature Sensor
6 Oil Service Valve 16 Oil Filter TCE Electronic Expansion Valve
7 Oil Separator 17 Suction Service Valve TC Expansion Valve
8 Discharge Service Valve 18 Schrader Valve OS Optical Sensor
9 Shutoff Valve 19 Refrigerant Tank FS Flow Switch
10 Filter Drier HHeater
Table 3. Device designators
Device Description Device Description
3BL1 Level Sensor; Oil Loss - Ckt 1 4BL1 Level Sensor; Oil Loss - Ckt 2
3BP1 Pressure Transducer; Suction Pressure - Ckt 1A 4BP1 Pressure Transducer; Suction Pressure - Ckt 2A
3BP2 Pressure Transducer; Discharge Pressure - Ckt 1 4BP2 Pressure Transducer; Discharge Pressure - Ckt 2
3BP3 Pressure Transducer; Oil Pressure - Ckt 1A 4BP3 Pressure Transducer; Oil Pressure - Ckt 2A
3BP4 Pressure Transducer; Liquid Pressure Microchannel Evap -
Ckt 1 4BP4 Pressure Transducer; Liquid Pressure Microchannel Evap - Ckt 2
3BP5 Economizer Pressure Sensor Circuit 1A 4BP5 Economizer Pressure Sensor Circuit 2A
3BP6 Economizer Pressure Sensor Circuit 1B 4BP6 Economizer Pressure Sensor Circuit 2B
3BP11 Pressure Transducer; Suction Pressure - Ckt 1B 4BP11 Pressure Transducer; Suction Pressure - Ckt 2B
3BP13 Pressure Transducer; Oil Pressure - Ckt 1B 4BP13 Pressure Transducer; Oil Pressure - Ckt 2B
3BT1 Temperature Sensor; Oil Temperature - Ckt 1A 4BT1 Temperature Sensor; Oil Temperature - Ckt 2A
3BT2 Temperature Sensor; Discharge Temperature - Ckt 1A 4BT2 Temperature Sensor; Discharge Temperature - Ckt 2A
3BT3 Temperature Sensor; Liquid Line Temperature
Microchannel Evap - Ckt 1A 4BT3 Temperature Sensor; Liquid Line Temperature Microchannel Evap - Ckt 2A
3BT4 Temperature Sensor; Evap Pool Temperature - Ckt 1A 4BT4 Temperature Sensor; Evap Pool Temperature - Ckt 2A
3BT5 Economizer Fast-acting Temperature Sensor - Ckt 1A 4BT5 Economizer Fast-acting Temperature Sensor - Ckt 2A
3BT6 Economizer Fast-acting Temperature Sensor - Ckt 1B 4BT6 Economizer Fast-acting Temperature Sensor - Ckt 2B
3BT11 Temperature Sensor; Oil Temperature - Ckt 1B 4BT11 Temperature Sensor; Oil Temperature - Ckt 2B
3BT12 Temperature Sensor; Discharge Temperature - Ckt 1B 4BT12 Temperature Sensor; Discharge Temperature - Ckt 2B
3K1 Electronic Expansion Valve - Ckt 1A 4K1 Electronic Expansion Valve - Ckt 2A
3K2 Economizer Expansion Valve - Ckt 1A 4K2 Economizer Expansion Valve - Ckt 2A
3K3 Economizer Expansion Valve - Ckt 1B 4K3 Economizer Expansion Valve - Ckt 2B
3M1 Motor; Compressor 1A 4M1 Motor; Compressor 2A
3M2 Motor; Compressor 1B 4M2 Motor; Compressor 2B
3M7 Solenoid; Oil - Compressor 1A 4M7 Solenoid; Oil - Compressor 2A
3M9 Solenoid; Oil - Compressor 1B 4M9 Solenoid; Oil - Compressor 2B
6B1 Switch; Evaporator Water Flow 6E50-1 Submersion Heater; Evaporator Shell Antifreeze Heater
6BT2 Temperature Sensor; Evaporator Leaving Water Temperature 6E50-2 Submersion Heater; Evaporator Shell Antifreeze Heater
6BT3 Temperature Sensor; Evaporator Entering Water Temperature 6E50-3 Submersion Heater; Evaporator Shell Antifreeze Heater
6E50-4 Submersion Heater; Evaporator Shell Antifreeze Heater
6E50-5 Heat Tape; Evaporator Shell Antifreeze Heater
6E50-6 Heat Tape; Evaporator Shell Antifreeze Heater

Operating Principles
RTAF-SVX002D-EN 9
Economizer
The economizer system's two main components are an
electronic expansion valve (EXV) and a brazed plate heat
exchanger (BPHE).
The liquid flow leaving the condenser is routed through
the economizer BPHE. One side is the economizer
refrigerant flow and the other side is the evaporator
refrigerant flow.
The economizer flow is expanded to a lower pressure and
temperature through the economizer EXV, then routed
through the BPHE to be superheated, and injected into the
compressor. The evaporator flow is subcooled further in
the BPHE and continues on to the evaporator EXV.

10 RTAF-SVX002D-EN
Start-Up and Shutdown
Important: Initial unit commissioning start-up must be
performed by Trane or an agent of Trane
specifically authorized to perform start-up
and warranty of Trane products. Contractor
shall provide Trane (or an agent of Trane
specifically authorized to perform start-up)
with notice of the scheduled start-up at least
two weeks prior to the scheduled start-up.
Unit Start-Up
If required, once the system has been operating for
approximately 30 minutes and has become stabilized,
complete the remaining start-up procedures, as follows:
1. Check the evaporator refrigerant pressure and the
condenser refrigerant pressure under Refrigerant
Report on the AdaptiView ™TD7. The pressures are
referenced to sea level (14.6960 psia).
2. Check the EXV sight glasses after sufficient time has
elapsed to stabilize the chiller. The refrigerant flow
past the sight glasses should be clear. Bubbles in the
refrigerant indicate either low refrigerant charge or
excessive pressure drop in the liquid line or a stuck
open expansion valve. A restriction in the line can
sometimes be identified by a noticeable temperature
differential between the two sides of the restriction.
Frost will often form on the line at this point. Proper
refrigerant charges are shown in the General
Information Section.
Important: A clear sight glass alone does not mean that
the system is properly charged. Also check
system subcooling, liquid level control and
unit operating pressures.
If chiller is limited by any limiting conditions, contact local
Trane service organization for more information.
Temporary Shutdown And
Restart
To shut the unit down for a short time, use the following
procedure:
1. Press the STOP key on the Adaptiview TD7. The
compressors will continue to operate and an
operational pumpdown cycle will be initiated.
2. Symbio™ 800 pump control will turn off the pump
(after a minimum 1 min. delay) when the STOP key is
pressed and automatically restart the pump when the
unit starts normally.
3. The unit will start normally, provided the following
conditions exist:
a. The Symbio™ 800 receives a call for cooling and the
differential-to-start is above the setpoint.
b. All system operating interlocks and safety circuits
are satisfied.
Extended Shutdown Procedure
The following procedure is to be followed if the system is
to be taken out of service for an extended period of time,
e.g. seasonal shutdown:
1. Test the unit for refrigerant leaks and repair as
necessary.
2. Open the electrical disconnect for the chilled water
pump. Lock the switches in the “OPEN” position.
3. Close all chilled water supply valves. Drain the water
from the evaporator.
4. With the water drained from evaporator, disconnect
115 power from evaporator heaters at terminals 1X4-1
and 1X4-2.
5. Open the main electrical disconnect and lock in the
“OPEN” position.
NOTICE
Equipment Damage!
Failure to follow instructions could result in equipment
damage.
Ensure that the compressor and oil sump heaters have
been operating properly for a minimum of 24 hours
before starting.
NOTICE
Equipment Damage!
Snow, ice, or debris build up on fans could cause
excessive imbalance and equipment damage.
Clear fans of build up prior to machine start-up.
NOTICE
Pump Damage!
Failure to follow instructions could result in pump
damage.
Lock the chilled water pump disconnects open and
verify pump is off before draining water.
NOTICE
Heater Damage!
Failure to follow instructions could result in heater
damage.
Do not apply power to the evaporator heaters when no
water is present.

Start-Up and Shutdown
RTAF-SVX002D-EN 11
6. At least every three months (quarterly), check the
refrigerant pressure in the unit to verify that the
refrigerant charge is intact.
Seasonal Unit Start-Up Procedure
1. Close all valves and re-install the drain plugs in the
evaporator.
2. Service the auxiliary equipment according to the start-
up/maintenance instructions provided by the
respective equipment manufacturers.
3. Close the vents in the evaporator chilled water circuits.
4. Open all the valves in the evaporator chilled water
circuits.
5. Open all refrigerant valves to verify they are in the
open condition.
6. If the evaporator was previously drained, vent and fill
the evaporator and chilled water circuit. When all air is
removed from the system (including each pass), install
the vent plugs in the evaporator water boxes.
7. Check the adjustment and operation of each safety and
operating control.
8. Refer to the sequence for daily unit startup for the
remainder of the seasonal startup.
System Restart After Extended
Shutdown
Follow the procedures below to restart the unit after
extended shutdown:
1. Verify that the liquid line service valves, oil line,
compressor discharge service valves and suction
service valves are open (backseated).
2. Check the oil sump level.
3. Fill the evaporator water circuit. Vent the system while
it is being filled. Open the vent on the top of the
evaporator and condenser while filling and close when
filling is completed.
4. Close the fused-disconnect switches that provides
power to the chilled water pump.
5. Start the evaporator water pump and, while water is
circulating, inspect all piping for leakage. Make any
necessary repairs before starting the unit.
6. While the water is circulating, adjust the water flows
and check the water pressure drops through the
evaporator. For water flow rates see “General Data,”
p. 6.
7. Verify proper operation of flow switch on the
evaporator waterbox.
8. Stop the water pump. The unit is now ready for start-
up as described previously.
NOTICE
Equipment Damage!
Failure to follow instructions could result in equipment
damage.
Lock the disconnect in the “OPEN” position to prevent
accidental start-up and damage to the system when it
has been shut down for extended periods.
NOTICE
Equipment Damage!
Failure to follow instructions could result in equipment
damage.
Ensure that the compressor and oil sump heaters have
been operating properly for a minimum of 24 hours
before starting.
NOTICE
Compressor Damage!
Failure to follow instructions below could cause
catastrophic damage to the compressor.
Do not leave oil line shut off valve or the isolation
valves closed on unit start-up.
NOTICE
Proper Water Treatment Required!
The use of untreated or improperly treated water could
result in scaling, erosion, corrosion, algae or slime. Use
the services of a qualified water treatment specialist to
determine what water treatment, if any, is required.
Trane assumes no responsibility for equipment failures
which result from untreated or improperly treated
water, or saline or brackish water.

Start-Up and Shutdown
12 RTAF-SVX002D-EN
Sequence of Operation
This section will provide basic information on chiller
operation for common events. With microelectronic
controls, ladder diagrams cannot show today’s complex
logic, as the control functions are much more involved
than older pneumatic or solid state controls.
Adaptive control algorithms can also complicate the exact
sequence of operations. This section illustrates common
control sequences.
Software Operation Overview
The Software Operation Overview shown below is a
diagram of the five possible software states. This diagram
can be though of as a state chart, with the arrows and
arrow text depicting the transitions between states.
• The text in the circles is the visible top level operating
mode displayed on Tracer™ AdaptiView.
• The shading of each software state circle corresponds
to the shading on the time lines that show the state the
chiller is in.
There are five generic states that the software can be in:
•PowerUp
•Stopped
•Starting
• Running
•Stopping
•
Timelines
• The time line indicates the upper level operating mode,
as it would be viewed on the Tracer AdaptiView.
• The shading color of the cylinder indicates the
software state.
• Text in parentheses indicates sub-mode text as viewed
on Tracer AdaptiView.
• Text above the time line cylinder is used to illustrate
inputs to the Main Processor. This may include user
input to the Tracer AdaptiView Touch screen, control
inputs from sensors, or control inputs from a Generic
BAS.
• Boxes indicate control actions such as turning on
relays, or pulsing compressor load or unload
solenoids.
• Smaller cylinders under the main cylinder indicate
diagnostic checks.
• Text outside a box or cylinder indicates time based
functions.
• Solid double arrows indicate fixed timers.
• Dashed double arrows indicate variable timers.
Important: Sequence of events timelines include
options that may not be available on
specific unit configurations.
Figure 2. Software operation overview
Shutting Down
Running
or
Running Limit
Stopped
or
Run Inhibit
RTAF Sequence of Operation:
Chiller State Chart
Auto
Command
Confirmed Start
Stop Command
Diagnostic
Confirmed
Shutdown
Boot and
Self Test
Stop Command or Diagnostic
Auto
or
Waiting to Start
Checkfor
Differential
to Start
Checkfor
Differential
to Stop
Release
of Inhibit
PowerUp

Start-Up and Shutdown
RTAF-SVX002D-EN 13
Power Up Diagram
The Power up chart shows the respective TD-7 AdaptiView
screens during a power up of the Symbio™ 800 and
display. This process takes 25 seconds for the Symbio™
800 and 100 seconds for the display. On all power ups, the
software model always will transition through the
'Stopped' Software state independent of the last mode. If
the last mode before power down was 'Auto', the
transition from 'Stopped' to 'Starting' occurs, but it is not
apparent to the user.
Figure 3. Sequence of operation: power up diagram
StoppedStopped
External
Power
Applied
Symbio 800 Fully
Operational
Booting Symbio 800
(15 Seconds)
Operator Display and
Symbio 800 Start Booting
Last Mode
Auto
Last Mode
Stop
IPC Bus Comm Begins
Booting Operator Display
(45 Seconds)
Display Finishes Booting
Display Starts Loading Data
Loading Display Data
(55 Seconds)
Display Finished Loading Data
See Figure 1
Remain in
“Stop”
indefinitely until
“Auto” command
See
“Stopped To Starting”
Starting Sequence
See “Power Up to
Starting” Sequence Diagram
Starting Sequence
See “Power Up to
Starting” Sequence Diagram
Symbio 800 Boot UpSymbio 800 Boot Up IF
Minimum Time Until First
Compressor Restarts
(39 Seconds)
Continue Along
Starting Sequence See
“Power Up to Starting”
*Display will show either Auto or Stop button active once it is fully loaded
Stopped
External
Power
Applied
Symbio 800 Fully
Operational
Booting Symbio 800
(15 Seconds)
Operator Display and
Symbio 800 Start Booting
Last Mode
Auto
Last Mode
Stop
IPC Bus Comm Begins
Booting Operator Display
(45 Seconds)
Display Finishes Booting
Display Starts Loading Data
Loading Display Data
(55 Seconds)
Display Finished Loading Data
See Figure 1
Remain in
“Stop”
indefinitely until
“Auto” command
See
“Stopped To Starting”
Starting Sequence
See “Power Up to
Starting” Sequence Diagram
Symbio 800 Boot Up IF
Minimum Time Until First
Compressor Restarts
(39 Seconds)
Continue Along
Starting Sequence See
“Power Up to Starting”

Start-Up and Shutdown
14 RTAF-SVX002D-EN
Power Up to Starting
The Power up to starting diagram shows the timing from
a power up event to energizing the 1st compressor. The
shortest allowable time would be under the following
conditions:
• No motor restart inhibit time left from subsequent
starts
• Evaporator Water flow occurs quickly with pump on
command
• Power up Start Delay set to 0 minutes
• Need to cool (differential to start) already exists
• Oil level is detected immediately
The above conditions would allow for a minimum power
up to starting the 1st compressor time of about 45 seconds
(variations may exist due to options installed). Note that it
is not advisable to start a chiller “cold”, the oil heaters
should be in operation for a sufficient length of time prior
to first start. Consult the chiller’s IOM for specifics.
Figure 4. Sequence of events: power up to starting
Confirm Presence
of Oil Within
90 Seconds
Confirm Presence
of Oil Within
90 Seconds
Confirm Presence
of Oil Within
90 Seconds
Power
Applied
* Lead Compressor (and its lead circuit) is
determined by staging algorithm – “Balanced”,
“Circuit 1 Lead”, or “Circuit 2 Lead” selection –
also influenced by lockouts, restart inhibit, or
diagnostics present
Fans pre-start,
EXVs moving to
Preposition
0 to 25 Seconds; Evap
Isolation Valve
Compressor Delay Time
has expired
Power
Up
Power
Up
Symbio
800
Boot Time
(15 Sec)
Auto Mode commanded
by Front Panel or BAS
EXVs self-
close on
power up
Confirm Evaporator Water Flow
(6 Second Filter)
Enforce Restart Inhibit Timer
(0 to 1 minute)
Power Up Delay Inhibit Timer
(User Adjustable 0 to 30 minutes)
AutoAuto
Energize Evaporator
Water Pump Relay
Confirm Evaporator Water
Flow Within 20 minutes
(6 Second Filter)
Confirm Evaporator Water
Flow Within 20 minutes
(6 Second Filter)
Oil Heaters
Always Energized
when Compressor
is De-energized
EXV remains closed
Wait for Need
To Cool
(Diff to Start)
AutoAuto
Call for Cooling**
(Differential to Start is met)
Waiting
To Start
Waiting
To Start
Confirm
Presence of Oil
(0 to 90 seconds)
Waiting
To Start
Waiting
To Start
Send Start Command
to Lead Compressor*
Transition to
Running
Start Control of
Condenser Fan Flow
Pre-Position EXV of
Lead Circuit
Check Evap Pressure for
Low Pressure Cutout
Check Evap Pressure for
Low Pressure Cutout
Pre-Position EXV of
Lead Circuit
Check Evap Pressure for
Low Pressure Cutout
Confirm Presence
of Oil Within
90 Seconds
Power
Applied
* Lead Compressor (and its lead circuit) is
determined by staging algorithm – “Balanced”,
“Circuit 1 Lead”, or “Circuit 2 Lead” selection –
also influenced by lockouts, restart inhibit, or
diagnostics present
Fans pre-start,
EXVs moving to
Preposition
0 to 25 Seconds; Evap
Isolation Valve
Compressor Delay Time
has expired
Power
Up
Symbio
800
Boot Time
(15 Sec)
Auto Mode commanded
by Front Panel or BAS
EXVs self-
close on
power up
Confirm Evaporator Water Flow
(6 Second Filter)
Enforce Restart Inhibit Timer
(0 to 1 minute)
Power Up Delay Inhibit Timer
(User Adjustable 0 to 30 minutes)
Auto
Energize Evaporator
Water Pump Relay
Confirm Evaporator Water
Flow Within 20 minutes
(6 Second Filter)
Oil Heaters
Always Energized
when Compressor
is De-energized
EXV remains closed
Wait for Need
To Cool
(Diff to Start)
Auto
Call for Cooling**
(Differential to Start is met)
Waiting
To Start
Confirm
Presence of Oil
(0 to 90 seconds)
Waiting
To Start
Send Start Command
to Lead Compressor*
Transition to
Running
Start Control of
Condenser Fan Flow
Pre-Position EXV of
Lead Circuit
Check Evap Pressure for
Low Pressure Cutout
**If Free Cooling is available, it shall be the first level control to start.
Partial Free Cooling: will always be attached to circuit 1 and circuit 2 will be the
lead circuit. If Free Cooling is available, then both compressors on circuit 2
should start before starting a compressor on circuit 1.
Total Free Cooling: balanced starts and hours or circuit x lead are available.
However, just like Partial Free Cooling, both compressors on a circuit should be
running before starting the other circuit.

Start-Up and Shutdown
RTAF-SVX002D-EN 15
Stopped to Starting
The figure below shows the timing from a stopped mode
to energizing the first compressor. The shortest allowable
time would be under the following conditions:
• No motor restart inhibit time left from subsequent
starts
• Evaporator Water flow occurs quickly with pump on
command
• Need to cool (differential to start) already exists
The above conditions would allow a compressor to start in
about 20 seconds.
Figure 5. Sequence of events: stopped to starting
6
/
/
66
1
2
/
/
22
2
0
1
2
-
1
2
/
/
2
2
1
1
/
/
1
2
0
1
2
Confirm Presence
of Oil Within
90 Seconds
6
/
6
1
1
1
1
1
/
/
5
5
/
/
/
5
2
2
2
2
2
/
/
/
/
0
0
0
0
0
0
0
C
0
0
1
1
1
1
1
1
1
C
2
2
2
2
2
2
2
o
Stopped
Or Run
Inhibit
*Lead Compressor (and its lead circuit)is
determined by staging algorithm– “Balanced”,
“Circuit 1 Lead”, or “Circuit 2 Lead” selection –
also influenced by lockouts, restart inhibit, or
diagnostics present
**Note:If Free Cooling is active, it will be the first
stage of cooling to stage on.
6
6
/
/
/
6
1
1
1
1
/
/
2
2
2
2
2
2
2
/
/
/
2
2
2
2
2
2
/
/
/
/
/
/
0
0
0
1
1
1
2
2
2
-
7
7
7
/
/
/
7
7
7
3
3
3
/
/
/
/
/
/
/
/
/
3
3
3
2
2
2
/
/
/
/
/
/
Stop
6
/
6
1
/
/
3
/
3
2
/
/
0
1
2
Auto Mode commanded
by Front Panel or BAS
Confirm Evaporator Water Flow
(6 Second Filter)
Enforce Restart Inhibit Timer
(0 to 1 minute)
7
7
7
7
/
/
/
/
/
7
7
7
7
2
2
2
2
/
/
/
/
/
/
/
/
/
/
/
/
2
2
2
2
2
2
2
2
/
/
/
/
/
/
/
0
0
0
0
1
1
1
1
2
2
2
2
-
-
9
9
9
9
/
/
/
/
/
9
9
9
9
3
3
3
3
/
/
/
/
/
/
/
/
/
/
/
/
3
3
3
3
2
2
2
2
/
/
/
/
/
/
/
0
0
0
0
1
1
1
1
2
2
2
2
Auto
EnergizeEvaporator
Water Pump Relay
6
/
/
6
6
1
2
/
/
22
2
0
1
2
-
1
2
/
/
22
1
1
/
/
1
2
0
1
2
ConfirmEvaporator Water
Flow Within 20 minutes
(6 Second Filter)
Oil Heaters
Always Energized when
Compressoris De-energized
6
/
/
/
6
1
1
/
/
/
/
4
4
4
/
/
4
2
2
/
/
/
/
0
W
1
W
2
a
7
/
7
3
/
/
/
3
2
2
/
/
0
1
2
EE
a
s
s
d
f
EXV remains closed
Wait for Need
To Cool
(Diff to Start)
9
9
9
9
9
9
/
/
/
/
/
/
/
/
/
9
9
9
9
9
9
2
2
2
2
/
/
/
/
/
/
/
/
/
/
/
2
2
2
2
2
2
2
2
/
/
/
/
/
/
0
0
0
0
1
1
1
1
2
2
2
2
-
1
1
1
1
0
0
0
0
/
/
/
/
/
0
0
0
0
2
2
2
2
/
/
/
/
/
/
/
/
/
/
/
2
2
2
2
2
2
2
2
/
/
/
/
/
/
0
0
0
0
1
1
1
1
2
2
2
2
Auto
9
r
/
9
3
/
/
/
3
2
2
2
/
/
0
0
0
1
1
(
(
2
2
D
D
i
a
s
s
d
f
Call for Cooling**
(Differential to Start is met)
1
1
1
1
0
0
1
1
1
1
0
0
0
1
2
2
0
0
0
0
0
0
0
/
/
/
/
/
/
/
0
0
0
0
0
0
0
1
1
1
1
1
1
/
/
/
/
/
/
/
//
/
/
/
/
/
/
/
2
2
2
2
2
2
2
/
/
/
/
/
/
/
/
/
//
0
0
0
0
0
0
0
1
1
1
1
1
1
2
2
2
2
2
2
2
-
-
1
1
1
1
1
1
0
0
0
0
0
0
0
/
/
/
/
/
/
/
0
0
0
0
0
0
0
3
3
3
3
3
3
3
/
/
/
/
/
/
/
/
//
1
1
1
1
1
1
/
/
/
/
/
/
/
2
2
2
2
2
2
2
/
/
/
/
/
/
/
/
/
//
0
0
0
0
0
0
0
1
2
2
Waiting
To Start
1
0
/
0
2
/
/
/
2
2
/
/
0
1
2
a
s
d
f
Confirm
PresenceofOil
(0to 90seconds)
1
1
1
1
1
1
0
0
0
0
0
0
0
/
/
/
/
/
/
/
0
0
0
0
0
0
0
3
3
3
3
3
3
3
/
/
/
/
/
/
/
/
/
/
0
0
0
0
0
0
0
/
/
/
/
/
/
/
0
0
0
0
0
0
0
2
2
2
2
2
2
2
/
/
/
/
/
/
/
/
/
/
0
0
0
0
0
0
0
1
1
1
1
1
1
2
2
2
2
2
2
2
-
-
1
1
1
1
1
1
2
2
2
2
2
2
2
/
/
/
/
/
/
/
2
2
2
2
2
2
2
1
1
1
1
1
1
/
/
/
/
/
/
/
//
1
1
1
1
1
1
/
/
/
/
/
/
/
2
2
2
2
2
2
2
/
/
/
/
/
/
/
/
/
//
0
0
0
0
0
0
0
1
1
1
1
1
1
2
2
2
2
2
2
2
Waiting
To Start
1
0
/
0
3
/
/
1
/
2
/
/
0
1
2
a
s
d
f
1
2
/
2
1
/
/
1
/
2
/
/
0
1
2
a
s
d
f
Fans pre-start,EXV
moving to
Preposition
0to25Seconds,Evap
Isolation Valve
Compressor Delay Time
has expired
Send Start Command
to Lead Compressor*
Transition to
Running
Start Control of
Condenser Fan Flow
Pre-Position EXVof
Lead Circuit
6
6
6
6
6
6
6
/
/
/
/
/
/
/
/
6
6
6
6
6
6
6
6
6
1
1
1
1
1
1
3
3
3
3
3
3
3
/
/
/
/
/
/
/
/
3
3
3
3
3
3
3
3
3
2
2
2
2
2
2
0
0
0
0
0
0
0
1
1
1
1
1
1
2
2
2
2
2
2
-
-
-
1
1
1
1
1
1
2
2
2
2
2
2
/
/
/
/
/
/
/
/
2
2
2
2
22
2
1
1
1
1
1
1
0
0
0
0
0
0
0
/
/
/
/
/
/
/
/
0
0
0
0
0
0
0
0
0
2
2
2
2
2
2
0
0
0
0
0
0
0
1
1
1
1
1
1
2
2
2
2
2
2
Check Evap Pressure for
Low Pressure Cutout
/
6
1
1
1
/
/
4
4
/
/
P
4
2
P
/
/
P
P
P
0
r
1
e
2
P
L

Start-Up and Shutdown
16 RTAF-SVX002D-EN
Running (Lead Compressor/Circuit Start and Run)
The figure below shows a typical start and run sequence
for the lead compressor and its circuit.
Figure 6. Sequence of operation: running (lead compressor/circuit start nd run)
Hold EXV Pre-position
(10 Seconds)
Lead
Compressor
Running
Chiller and Lead Circuit
Mode is “Running” -Lag
Circuit Mode is “Auto”
Hold EXV of Lead
Circuitatpre-
position for 10 sec
De-energize
Oil Heaters
Of Lead Circuit
Control Lead Circuit
Condenser Fans for
Optimum Differential
Pressure,
ƒ(Cprsr Spd, OA Temp)
6
6
6
/
/
/
/
66
66
66
1
1
1
2
2
2
/
/
/
/
2
2
2
2
2
2
2
2
2
0
0
0
1
1
1
2
2
2
-
1
1
1
2
2
2
/
/
/
/
22
22
22
1
1
1
1
1
1
/
/
/
/
1
1
1
2
2
2
0
0
0
1
1
1
2
2
2
Enforce All Running Mode Diagnostics for Chiller,Lead Compressor and its Circuit
Modulate EXV for
Pressure Control
Modulate
Compressor
for Limit
Control
Modulate Compressor
for
Capacity Control
Modulate Compressor
for
Capacity Control
6
6
6
/
/
/
/
6
6
6
1
1
1
/
/
/
/
/
2
2
2
/
/
/
/
2
2
2
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
-
7
7
7
/
/
/
/
7
7
7
2
2
2
/
/
/
/
/
4
4
4
/
/
/
/
4
4
4
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
Running
6
/
6
6
1
3
/
/
33
2
0
1
2
7
7
7
/
/
/
/
/
/
/
7
7
7
2
2
2
2
2
/
/
/
/
/
/
/
3
3
3
/
/
/
/
3
3
3
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
-
8
8
8
/
/
/
/
8
8
8
1
1
1
/
/
/
/
/
4
4
4
/
/
/
/
4
4
4
2
2
2
/
/
/
/
/
0
0
Running
7
/
7
7
2
4
2
2
/
/
4
4
2
0
1
2
8
/
/
/
8
1
/
/
4
/
/
/
4
2
/
/
0
1
2
-
9
/
/
/
9
1
/
/
1
/
/
/
2
/
/
0
1
2
Running
Lead Circuit:
Running Limit
8
/
8
8
1
5
/
/
5
5
2
0
1
2
6
/
/
/
6
6
1
1
1
1
1
1
3
3
3
3
/
/
/
/
3
3
3
3
3
3
2
2
2
2
2
2
2
2
0
0
0
0
0
0
0
0
1
1
1
1
1
1
2
2
2
2
2
2
M
i
l
e
s
t
s
s
o
n
n
n
n
n
n
e
e
e
e
D
D
D
D
e
e
e
e
e
e
e
e
e
e
D
D
D
D
DD
DD
s
s
s
s
c
c
c
c
s
s
s
s
s
s
r
r
r
r
i
i
i
i
i
i
p
p
p
p
p
t
t
t
t
t
p
p
p
p
p
p
i
i
i
i
i
i
o
o
o
o
n
n
n
n
9
9
9
/
/
/
/
9
9
9
1
1
1
/
/
/
/
/
0
0
0
/
/
/
/
0
0
0
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
-
1
1
1
0
0
0
/
/
/
/
0
0
0
2
2
2
/
/
/
/
/
9
9
9
/
/
/
/
9
9
9
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
Running
9
r
/
/
/
9
99
1
1
/
/
1
2
0
1
2
Exit
LimitMode
Enter
LimitMode Stage On
Setpoint Met*
1
0
/
/
/
0
2
/
/
8
/
/
/
8
2
/
/
0
1
2
-
1
2
/
/
/
2
1
/
/
1
/
/
/
2
/
/
0
1
2
Running
Lag Circuit:
Waiting to Start
1
1
1
r
0
0
0
/
0
0
2
9
2
2
/
9
9
2
0
1
2
Prepare to Start
Lag Compressor,
Check for Oil,
Check for LPC
EXV moving to preposition
0to25Seconds
Start Control of
Condenser Fan Flow
on Lag Circuit
Send Start Command
to Lag Compressor
Continue
Running
Pre-PositionEXVof
Lag Circuit
1
2
/
22
1
1
1
/
/
1
2
0
1
2
*Note:The decision to stage on or off another compressor is determined by
the Average Running Compressor Load Command,Water Temperature Error,and Time Since Last Stage
CircuitX Lead:A compressor on the selected circuitwill lead followed bya compressor on the alternate circuit,given an
appropriately increasing chiller load.Additional compressors will alternate between lead and lag circuits.Variable speed
compressors will always bethefirstcompressors to startand lastcompressors to stop.

Start-Up and Shutdown
RTAF-SVX002D-EN 17
Running (Lag Compressor/Circuit Start and Run)
The figure below shows a typical start and run sequence
for the lag compressor and its circuit.
Figure 7. Sequence of operation: running (lag compressor/circuit start nd run)
*Note:The decision to stageon or off another compressor is determined by
the Average Running Compressor Load Command, Water Temperature Error,and Time Since Last Stage
All
Compressors
Running
Chiller and Both Circuit
Modes are “Running”
Modulate
Compressor for
Capacity Control
De-energize
Oil Heaters
Of Lag Circuit
Control Both Circuit
Condenser Fans for
Optimum Differential
Pressure,
ƒ(Cprsr Spd,OA Temp)
6
6
6
/
/
/
/
6
6
6
6
6
6
1
1
1
2
2
2
/
/
/
/
22
22
22
2
2
2
0
0
0
1
1
1
2
2
2
-
1
1
1
2
2
2
/
/
/
/
2
2
2
2
2
2
1
1
1
1
1
1
/
/
/
/
1
1
1
2
2
2
0
0
0
1
1
1
2
2
2
Enforce All Running Mode Diagnostics for Chiller,Lead Compressor and its Circuit
Modulate
Compressor
for Limit
Control Modulate Compressor
for
Capacity Control
6
6
6
/
/
/
/
6
6
6
1
1
1
/
/
/
/
/
2
2
2
/
/
/
/
2
2
2
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
-
7
7
7
/
/
/
/
7
7
7
2
2
2
/
/
/
/
/
4
4
4
/
/
/
/
4
4
4
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
Running
6
/
6
6
1
3
/
/
33
2
0
1
2
7
7
7
/
/
/
/
/
/
/
7
7
7
2
2
2
2
2
/
/
/
/
/
/
/
3
3
3
/
/
/
/
3
3
3
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
-
8
8
8
/
/
/
/
8
8
8
1
1
1
/
/
/
/
/
4
4
4
/
/
/
/
4
4
4
2
2
2
/
/
/
/
/
Running
7
/
77
2
4
2
2
/
4
4
2
0
1
2
6
/
/
/
6
6
1
1
1
1
1
1
3
3
3
3
/
/
/
/
3
3
3
33
2
2
2
2
2
2
2
2
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
2
2
2
2
2
2
2
M
i
l
e
s
t
s
s
o
n
n
n
n
n
n
e
e
e
e
D
D
D
D
D
e
e
e
e
e
e
e
e
e
e
e
D
D
D
D
D
D
D
DD
s
s
s
s
c
c
c
c
s
s
s
s
s
s
r
r
r
r
i
i
i
i
i
i
p
p
p
p
p
t
t
t
t
t
p
p
p
p
p
i
i
i
i
i
i
o
o
o
o
n
n
n
n
Exit
LimitMode
Enter
LimitMode
1
1
1
0
0
0
0
/
/
/
/
0
0
0
0
2
2
2
/
/
/
/
/
8
8
8
8
/
/
/
/
8
8
8
8
2
2
2
/
/
/
/
/
0
0
0
0
1
1
1
2
2
2
-
1
1
1
2
2
2
/
/
/
/
2
2
2
1
1
1
/
/
/
/
/
/
1
1
1
/
/
/
/
2
2
2
/
/
/
/
/
0
0
0
0
1
1
1
2
2
2
Running
Energize Maximum
Capacity Relay after the
Adjustable Filter Time
(0to 1500Seconds)
Continue
Running
(All
Cprsrs &
Max
Capacity
Maximum Capacity
Submode
9
9
9
/
/
/
/
9
9
9
1
1
1
/
/
/
/
/
1
1
1
/
/
/
/
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
-
1
1
1
0
0
0
/
/
/
/
0
0
0
3
3
3
/
/
/
/
/
0
0
0
/
/
/
/
0
0
0
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
Running
/
/
/
8
1
/
/
3
/
/
/
3
2
/
/
0
1
2
-
9
/
/
/
9
1
/
/
1
/
/
/
2
/
/
0
0
0
1
1
2
Running
Lag Circuit:
Running Limit
9
/
99
1
1
/
/
1
2
0
1
2
8
/
8
8
1
3
/
/
3
3
2
0
1
2
1
1
1
o
r
0
0
0
r
/
/
/
0
0
0
0
3
0
0
/
/
00
2
0
1
2
2
2
All Compressors Running
At or Near Max Capacity
(Unable to Achieve CWSP)
Modulate EXV for
Pressure Control

Start-Up and Shutdown
18 RTAF-SVX002D-EN
Satisfied Setpoint
The figure below shows the normal transition from
Running to shutting down due to the Evap Leaving water
temp falling below the differential to stop setpoint.
Figure 8. Sequence of events: satisfied setpoint
*Operational Pumpdown is required if the Outdoor Air Temperature is less than 50F, or the Entering
Evaporator Water Temperature is greater than (outdoor air temperature – 10°F). With AFD, compressors
will be atmax speed for operational pumpdown.
** Operational pumpdown is terminated normally in the following configurations when:
Water with 2-Pass Evaporator:
-The evaporator (suction)pressure is at or below the “Pumpdown Termination Pressure” setting OR
LERTC saturated pressure (28.6F), which ever is greater
-Thecondenser (compressordischarge)pressureexceeds 315psia.
-Thecompressorpressureratio exceeds 8.
-The systemdifferential pressure exceeds 265psid or <25min.
Glycol with 2-Pass Evaporator:
The evaporator (suction)pressure is at or below the “Pumpdown Termination Pressure” setting OR
LERTC saturated pressure (per guidance -5F minimum), which ever is greater
-Thecondenser (compressordischarge)pressureexceeds 315psia.
-Thecompressorpressureratio exceeds 8.
-The systemdifferential pressure exceeds 265psid or <25min.
Water with Single Pass Evaporator:
-The evaporator (suction)pressure is at or below the “Pumpdown Termination Pressure” setting OR
LERTC saturated pressure (32F), which ever is greater
-Thecondenser (compressordischarge)pressureexceeds 315psia.
-Thecompressorpressureratio exceeds 12.3
-The systemdifferential pressure exceeds 265psid.
Glycol with Single Pass Evaporator:
-The evaporator (suction)pressure is at or below the “Pumpdown Termination Pressure” setting OR
LERTC saturated pressure (per guidance -5F minimum), which ever is greater
-Thecondenser (compressordischarge)pressureexceeds 315psia.
-Thecompressorpressureratio exceeds 12.3
-The systemdifferential pressure exceeds 265psid.
The maximumallowed time for Operational Pumpdown is Max Pumpdown Time setting (default to 120
sec.)*number of compressors configured on the circuit.
***Automatic evaporator isolation valve control will close valve if Outdoor Ambient Air Temperature at
circuit shutdown is less than evaporator leaving water cutout setpoint plus 3°C.
****If Condenser Refrigerant Tanks are installed
8
/
/
/
8
1
/
/
0
/
/
/
0
2
/
/
0
1
2
-
1
0
/
/
/
0
1
/
/
3
/
/
/
3
2
/
/
0
1
2
Shutting Down
Last Circuit Mode: Shutting Down
SubMode:Operational Pumpdown*
6
/
/
/
/
6
1
/
/
2
/
/
/
/
2
2
/
/
0
1
2
-
8
/
/
/
/
8
1
/
/
0
/
/
/
/
0
2
/
/
0
1
2
Running
LastCircuitMode:
Running
1
0
/
/
/
/
0
1
/
/
3
/
/
/
/
3
2
/
/
0
1
2
-
1
2
/
/
/
/
2
1
/
/
1
/
/
/
/
2
/
/
0
1
2
Auto
Both CircuitModes:
Waiting for Need to Cool
8
/
8
8
1
1
/
1
2
0
1
2
6
/
6
6
1
3
/
3
3
2
0
1
2
Running
Last
Compressor
AtMin
Capacity
1
0
/
00
1
4
/
44
2
0
1
2
DifferentialtoStopisMet
Operational Pumpdown
(See max time allowed below)
FullyCloseEXV
Close Condenser
Rfgt Tank Solenoid
Valve****
Send Stop Command
To Compressor(s)
IF*No Pumpdown Required
Pumpdown
Required
Turn Off Last Circuit’s
Condenser Fans
Normal Pumpdown Termination**
Criteria is Met for Last Circuit
6
6
6
6
6
/
/
/
/
/
/
6
6
6
6
6
6
1
1
1
1
1
2
2
2
2
2
/
/
/
/
/
/
2
2
2
2
2
2
2
2
2
2
2
0
0
0
0
0
1
1
1
1
1
2
2
2
2
2
-
-
1
1
1
1
1
2
2
2
2
2
/
/
/
/
/
/
2
2
2
22
2
1
1
1
1
1
1
1
1
1
1
/
/
/
/
/
/
1
1
1
1
1
2
2
2
2
2
0
0
0
0
0
1
1
1
1
1
2
2
2
2
2
Enforce All Non Running
Mode Diagnostics
6
/
6
1
1
1
1
1
1
/
/
5
5
5
5
5
/
/
/
/
5
5
5
5
2
2
2
2
2
2
/
/
/
/
/
/
/
/
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
E
2
2
2
2
2
2
2
2
E
n
1
2
/
22
1
1
/
1
2
0
1
2
Auto
Close EXV
(0 to 25 Seconds)
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
/
/
/
/
/
/
/
/
2
2
2
2
2
2
2
2
1
1
1
1
1
1
1
1
/
/
/
/
/
/
/
/
/
/
/
/
/
1
1
1
1
1
1
1
1
/
/
/
/
/
/
/
/
/
2
2
2
2
2
2
2
2
2
2
2
2
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
0
0
1
2
1
1
1
1
1
1
1
1
n
n
2
2
2
2
2
2
2
2
n
i
/
/
/
/
/
/
/
/
/
i
n
2
2
2
2
i
1
1
1
1
1
1
1
1
n
g
/
/
/
/
/
/
/
/
n
1
1
1
1
1
1
1
1
g
/
/
/
/
/
/
/
/
/
/
2
2
2
2
2
2
2
2
2
2
2
/
/
/
/
/
/
/
/
/
/
/
/
//
0
0
0
1
2
EnergizeLastCircuit
Oil Heaters
6
/
66
1
1
1
1
/
/
3
3
3
3
3
3
3
/
/
/
/
3
3
3
3
2
2
2
2
2
2
/
/
/
/
/
/
/
/
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
6
/
6
6
1
2
/
2
2
2
0
1
2
-
1
2
/
22
1
0
/
00
2
0
1
2
Check for
Normal Pumpdown
Termination Criteria Met ** ***Automatic Evaporator
Isolation Valve control may
closevalve
PerformOperational
PumpdownforLast
Circuit if Required

Start-Up and Shutdown
RTAF-SVX002D-EN 19
Unloading Unstaging
The figure below shows the normal transition from full
load to minimum load while the chiller is running.
Figure 9. Sequence of events: Unloading unstaging
Running
(All
Compressors
&Max
Capacity)
All Compressors Running At
Less Than Max Capacity
De-Energize the
Maximum Capacity
Relay after
AdjustableFilter
Time (0 to 600Sec)
RemoveMaximum
Capacity Submode
6
6
6
/
/
/
/
6
6
6
1
1
1
/
/
/
/
/
/
2
2
2
/
/
/
/
2
2
2
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
-
7
7
7
/
/
/
/
7
7
7
3
3
3
/
/
/
/
/
0
0
0
/
/
/
/
0
0
0
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
Running
6
/
66
1
3
/
/
3
3
2
0
1
1
2
2
2
2
StageOff Setpoint Met***
7
/
/
/
7
3
/
/
0
/
/
/
0
2
/
/
0
1
2
-
9
/
/
/
9
2
/
/
7
/
/
/
7
2
/
/
0
1
2
Running
Lag Circuit Mode: Shutting Down
SubMode:Operational Pumpdown*
Operational Pumpdown
(0 Seconds to
Max Pumpdown Timer(Default:2 min.))
Fully Close EXV
Close Condenser
Rfgt Tank Solenoid
Valve****
IF*No Pumpdown Required
Pumpdown
Required
Close EXV
(0 to 25 Seconds)
7
/
7
7
3
0
/
/
0
0
2
2
0
0
0
1
1
2
2
Normal Pumpdown Termination**
Criteria is Met for Last Circuit
Send Stop
Command To Lag
Compressor
2
2
0
0
1
2
Continue to Control Capacity
by Modulating Compressor
Capacity (Speed,Port Loader,
Economizer)
*** Note:The decision to stage off another compressor is determined by the
Average Running Compressor Load Command,Water Temperature Error,
and Time since Last Stage. Compressors will stage off in the reverse order
they staged on.All fixed speed compressors will stage off before variable
speed compressors stageoff.
**** If Condenser Refrigerant Tank is installed.
*Operational Pumpdown is required if the Outdoor Air Temperature is less
than 50F, or the Entering Evaporator Water Temperature is greater than
(outdoor air temperature –10F).With AFD,compressors will be atmax
speed for operational pumpdown.
Stop Lag Circuits
Condenser Fans
EnergizeLag
CircuitHeaters
9
9
9
9
9
9
/
/
/
/
/
/
/
9
9
9
9
9
9
2
2
2
2
2
2
/
/
/
/
/
/
/
/
/
7
7
7
7
7
7
/
/
/
/
/
/
/
7
7
7
7
7
7
2
2
2
2
2
2
/
/
/
/
/
/
/
/
/
0
0
0
0
0
0
1
1
1
1
1
1
2
2
2
2
2
2
-
1
1
1
1
1
1
1
1
1
1
1
1
/
/
/
/
/
/
/
4
4
4
4
4
4
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
4
4
4
4
4
4
2
2
2
2
2
2
/
/
/
/
/
/
/
/
/
0
0
0
0
0
0
1
1
1
1
1
1
2
2
2
2
2
2
Running
Lag CircuitMode:Auto
Continue to Control
Capacity by Modulating
Lead Compressor
Running Last
Compressor at
Min Capacity
/
/
9
9
2
2
2
2
8
8
8
2
2
22
/
/
/
8
88
2
0
1
1
1
2
2
2
1
1
1
1
1
1
/
/
/
/
4
4
4
/
/
/
/
/
/
/
/
/
4
4
4
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
-
1
1
1
2
2
2
/
/
/
/
2
2
2
1
1
1
/
/
/
/
/
/
1
1
1
/
/
/
/
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
Running
1
1
1
1
/
1
5
/
/
5
5
2
0
1
2
6
6
6
6
6
/
/
/
/
/
/
6
6
6
6
6
6
1
1
1
1
1
2
2
2
2
2
/
/
/
/
/
/
2
2
2
22
2
2
2
2
2
2
0
0
0
0
0
1
1
1
1
1
2
2
2
2
2
-
-
-
7
7
7
7
7
/
/
/
/
/
/
7
7
7
77
7
3
3
3
3
3
0
0
0
0
0
/
/
/
/
/
/
0
0
0
0
0
0
2
2
2
2
2
0
0
0
0
0
1
1
1
1
1
2
2
2
2
2
Enforce All Running
Mode Diagnostics
7
7
7
7
7
7
/
/
/
/
/
/
7
7
7
7
7
7
7
7
3
3
3
3
3
3
0
0
0
0
0
0
/
/
/
/
/
/
0
0
0
0
00
0
2
2
2
2
2
2
0
0
0
0
0
0
1
1
1
1
1
1
2
2
2
2
2
2
-
-
9
9
9
9
9
9
/
/
/
/
/
/
9
9
9
9
9
9
9
2
2
2
2
2
2
8
8
8
8
8
8
2
2
2
2
2
2
2
/
/
/
/
/
/
8
8
8
8
8
8
8
8
2
2
2
2
2
2
0
0
0
0
0
0
1
1
1
1
1
1
2
2
2
2
2
2
Enforce All Non Operational Pumpdown
Diagnostics
7
7
7
7
7
7
7
/
/
/
/
/
/
/
/
7
7
7
7
7
7
7
3
3
3
3
3
3
3
/
/
/
/
/
/
/
/
/
/
/
/
/
0
0
0
0
0
0
0
/
/
/
/
/
/
/
/
0
0
0
0
0
0
0
2
2
2
2
2
2
2
2
2
/
/
/
/
/
/
/
/
/
/
/
/
/
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
2
2
2
2
2
2
2
E
9
9
9
9
9
9
9
d
/
/
/
/
/
/
/
/
o
9
9
9
9
9
9
9
2
2
2
2
2
2
2
o
w
/
/
/
/
/
/
/
/
/
o
8
8
8
8
8
8
8
w
/
/
/
/
/
/
/
/
n
8
8
8
8
8
8
8
2
2
2
2
2
2
2
n
2
2
/
/
/
/
/
/
/
/
/
n
0
0
9
9
9
9
9
9
/
/
/
/
/
/
9
9
9
9
9
9
9
9
2
2
2
2
2
2
8
8
8
8
8
8
2
2
2
2
2
2
2
/
/
/
/
/
/
8
8
8
8
8
8
8
8
2
2
2
2
2
2
0
0
0
0
0
0
1
1
1
1
1
1
2
2
2
2
2
2
-
-
1
1
1
1
1
1
2
2
2
2
2
2
/
/
/
/
/
/
2
2
2
2
2
2
2
2
1
1
1
1
1
1
1
1
1
1
1
1
/
/
/
/
/
/
1
1
1
1
1
1
2
2
2
2
2
2
0
0
0
0
0
0
1
1
1
1
1
1
2
2
2
2
2
2
Enforce Running Mode Diagnostics for Chiller,
LastCompressorand its Circuit
6
/
66
1
2
/
22
2
0
1
2
-
1
2
/
2
2
1
1
/
1
2
0
1
2
Check for Normal
Pumpdown Termination
Criteria Met **
6
/
6
1
1
1
1
1
/
/
4
4
4
4
4
4
/
/
/
/
4
4
4
2
2
2
2
2
/
/
/
/
/
/
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
2
2
2
2
2
2
2
**Operational Pumpdown - See Satisfied Setpoint Operational
Pumpdown sequence diagramforspecific criteria.
PerformOperational
Pumpdown for Last
Circuit if Required*

Start-Up and Shutdown
20 RTAF-SVX002D-EN
Normal Shutdown to Stopped or Run Inhibit
The figure below shows the Transition from Running
through a Normal (friendly) Shutdown. The Dashed lines
on the top attempt to show the final mode if you enter the
stop via various inputs.
Figure 10. Sequence of events: normal shutdown to stopped or run inhibit
*Operational Pumpdown is required if the Outdoor Air
Temperature is less than 50F, or the Entering Evaporator Water
Temperature is greater than (outdoor air temperature – 10°F). With
AFD,compressors will be at max speed for operational
pumpdown.
**Operational Pumpdown: See Satisfied Setpoint Operational
Pumpdown sequence diagramfor specific criteria
***Automatic evaporatorisolation valve control will close valve if
Outdoor Ambient Air Temperature at circuit shutdown is less than
evaporator leaving water cutout setpoint plus 3°C.
The maximumallowed time for Operational Pumpdown is:Max
pumpdown time =setting x number of compressors configured on
the circuit.
Note:If Free Cooling is active, the last stage of cooling to turn off
will be Free Cooling.
/
/
/
6
1
/
/
2
/
/
/
2
2
/
/
0
1
2
-
8
/
/
/
8
1
/
/
5
/
/
/
5
2
/
/
0
1
2
Shutting Down
Running Circuit Modes: Shutting Down
SubMode:Operational Pumpdown*
8
/
8
8
1
5
/
5
5
2
0
1
2
1
2
/
2
2
1
1
/
1
2
0
1
2
6
/
66
1
3
/
3
3
2
0
1
2
Operational Pumpdown
(See max allowed time below)
Fully Close EXV
PerformOperational
PumpdownforAll
Running Circuits if
Required*
IF*
Close EXV
(0to 25Seconds)
2
2
0
0
1
2
6
/
6
6
1
2
/
22
2
0
1
2
-
1
2
/
22
1
1
/
1
2
0
1
2
Check for
Normal Pumpdown
Termination Criteria Met **
6
/
/
66
1
1
1
1
1
/
/
5
5
5
5
/
/
5
2
2
2
2
2
2
/
/
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
2
2
2
2
2
2
2
No Pumpdown Required
Pumpdown
Required
Evaporator Pump Off Delay
(Adjustable 1 to 30 Minutes)
Send Stop Command to
All
Running Compressors
EnergizeAll Heaters
Fully Close Both EXVs
Turn Off All Running
Circuits Condenser Fans
De-Energize Evaporator
Water Pump Relay
Stopped
or
Run Inhibit
One or
More
Circuits
Running
Normal Pumpdown Termination**
Criteria is Met for All Circuits
Local Stop
Chiller Level Diagnostic – Normal Shutdown Latched
Chiller Level Diagnostic – Normal Shutdown Nonlatched
Building Automation SystemStop
External Auto-Stop
8
r
r
i
i
/
a
a
8
aa
1
aa
/
/
a
a
5
i
i
ss
/
s
s
5
ss
2
ss
/
/
sss
0
M
M
1
M
M
2
e
e
-
t
t
1
f
f
oo
0
o
o
/
rr
0
1
rr
A
A
/
/
rr
A
A
/
A
A
l
l
A
A
2
l
l
/
/
ll
ll
0
C
C
C
C
2
i
i
r
r
Shutting Down
CircuitModes:
Auto
1
0
/
0
1
/
/
6
/
6
2
/
/
0
1
2
-
1
2
/
2
1
/
/
1
/
2
/
/
0
1
2
Stopped or Run Inhibit
CircuitModes:
Stopped or Auto
1
0
/
00
1
7
/
7
7
2
0
1
2
Automatic Evaporator
Isolation Valve control
may close valve
Economizer –EEV and
port loader close