Trane CG-PRC007-EN User Manual
Air-Cooled
Liquid Chillers
10 to 60 Tons
April 2004
CG-PRC007-EN
Introduction
Air-Cooled
Liquid Chillers
Design and manufacturing excellence
makes Trane a leader in the air-cooled
chiller marketplace. For over 40 years,
Trane has been using the best
engineering available in development,
manufacturing, and marketing to
produce quality products. This tradition
of using excellence to meet market
demands is illustrated with the Trane 10
to 60-ton air-cooled chillers.
10, 15 Tons
© 2003 American Standard Inc. All rights reserved
20–60 Tons
CG-PRC007-EN
Contents
Introduction
Features and Benefits
Application Considerations
Selection Procedure
Model Number Description
General Data
Performance Data
Performance Adjustment Factors
Controls
Electric Power
Dimension and Weights
Mechanical Specifications
2
4
9
14
15
16
21
17
30
37
39
48
CG-PRC001-EN
3
Features and
Benefits
(10–60 Ton)
Installation
Small size, complete factory wiring, easy
lifting provisions, factory installed
options and start-up control provide fast,
easy installation. A complete factory run
test is performed on each unit,
eliminating potential start-up problems.
Integrated Comfort Systems
All Trane chillers are ICS compatible. A
simple twisted wire pair is all it takes to
hook an air-cooled chiller into a Tracer
system. An ICS system provides the
most advanced diagnostics, monitoring,
and control that the industry can offer.
Only Trane can supply the entire package.
ICS provides comfort with one word —
Trane.
Packed Stock Increases
Project Flexibility
Trane 10 to 60-ton air-cooled chillers
are available through the most flexible
packed stock program in the industry.
Trane knows you want your units on
the jobsite, on time, when you need
them. To help meet this demand, Trane
keeps a multitude of unit sizes and
voltages in packed stock. Many of
these include optional features such as
isolators, low ambient head pressure
controls and refrigerant gauge piping.
You no longer have to settle for a
scaled-down, basic unit to meet your
job schedule. In many cases, units can
be shipped directly to the jobsite from
packed stock!
CG-PRC007-EN4
Features and
Benefits
(10–15 Ton)
The 10 and 15-ton air-cooled Cold
Generator
drive hermetic scroll compressors, has
outstanding standard features and
additional benefits that make selection,
installation, and servicing easy.
™
chillers, with Trane direct
Flexibility
Footprint
Central to the design of any project is the
operating envelope of the air-cooled
packaged chiller. With this in mind, Trane
builds the chillers to make the most
efficient use of the available installation
space. The Trane CGA model chillers are
extremely compact. They have the
lightest weight, the smallest footprint,
and the lowest silhouette of any chiller in
the industry.
Less Weight
These lightweight models afford less
stress on building supports and greater
handling ease.
Installation
Installation time and effort are reduced
when dealing with a significantly smaller
and lighter unit. In addition, having
electrical and water connections on the
same side of the unit and a single-point
main power connection serves to make
installation easier. The unit arrives at the
jobsite fully assembled, tested, charged
and ready to provide chilled water.
Ease of Service
The control panel and unit panels are
completely removable for service
accessibility and convenience.
ICS Interface
™
Communication with Trane Tracer
™
Tracker
Interface on the 10 and 15 ton Cold
Generator chiller.
is possible through the ICS
or
Optional Features
• Hot Gas Bypass — Allows unit
operation below the minimum step of
unloading.
• Low Ambient Head Pressure Control
— Modulates the rpm of the fan motor
in response to outdoor ambient
temperature and unit head pressure.
Provides unit cooling operation down
to outdoor temperatures of 0°F.
• Coil Guard — Metal grille with PVC
coating to protect the condenser coil.
• Isolation — Neoprene in shear or
spring flex isolators.
• Power Supply Monitor — Provides
protection against phase loss, phase
reversal, phase imbalance, incorrect
phase sequence and low line voltage.
• Elapsed Time Meter/Number Starts
Counter — Records number of
compressor starts and operating
hours.
• Flow Switch — Required as a safety
interlock to prevent operation of unit
without evaporator flow (available
option for field installation only).
• Integrated Comfort Systems (ICS)
Interface — Provides the ability to
communicate with Trane Tracer or
Tracker building management systems
via a Thermostat Control Module —
(TCM).
• Gauges — Monitor suction and
discharge pressures.
5CG-PRC007-EN
Features and
Benefits
(20–60 Ton)
Trane’s 20-60 ton chillers offer the same
time-tested and proven control
technology that is applied to the
IntelliPak Air Cooled rooftops.
Superior control makes the IntelliPak a
truly advanced chiller.
Standard Features
Microprocessor Control
The IntelliPak chiller’s Unit Control
Module (UCM) is an innovative,
modular microprocessor control
design. It coordinates the actions of the
chiller in an efficient manner and
provides stand-alone operation of the
unit. A Human Interface (HI) Panel is a
standard component of the IntelliPak
Chiller. Access to all unit controls is via
the Human Interface Panel.
Factory Run Testing
In addition to outstanding efficient
performance, IntelliPak Chillers have
established a reputation for reliable
operation. Aside from the individual
component tests, all Trane 20 to 60-ton
chillers are factory run tested with
water running through the evaporator
to confirm proper operation. Control
operation and current draw are both
monitored to assure safe, reliable
operation.
Other Standard Features
• Trane 3-D Scroll compressors
• Advanced motor protection
• 300 psi waterside evaporator
• Evaporator insulation (¾-inch
Armaflex II or equivalent)
• Evaporator heat tape (thermostat
controlled)
• Condenser coil guards
• Operation down to 30°F without
additional wind baffles or head
pressure control
• Loss of flow protection
• UL and CSA approval available
• Packed stock availability
• Control Power Transformer
• Low ambient lockout
• Plain English (Spanish/French)
Human Interface display
• Smart Lead/Lag operation
• Integrated chilled solution pump
control
• Selectable process or comfort control
algorithm
• External auto/stop
• Electronic low ambient damper
control integrated into UCM
• Flow switch
• Strainer/connection kit
Optional Features
• Controls for ice making operation
Miscellaneous Options
• Trane Communications Interface
Module (TCI)
• Unit Mounted Disconnect
• Isolators
• Superheat/Sub-Cooling Module
• Hot Gas Bypass
• Generic B A S Modules with 0-10 v
analog input/output, 0-5 v analog
input/binary output
• Remote Human Interface Panel
(RHI)
• Remote Set point Potentiometer
• Zone Sensor (Chilled Solution
Reset)
• Copper Fin Condenser Coils
• Electronic Low Ambient Damper(s)
• Inter-Processor Communication
Bridge (IPCB)
• Ice building control
• Other options
In addition to all of these options, Trane
can offer in-house design for many
applications, including special coil
coating.
CG-PRC007-EN6
Enhanced Controls
IntelliPak Chiller Unit Control Module
(UCM)
Microprocessor Control
The brain of the 20 to 60 ton air-cooled
chiller is its Unit Control Module (UCM).
The UCM is an innovative, modular
microprocessor control design, which
coordinates the actions of the chiller in
an efficient manner, providing standalone operation of the unit.
Access to the unit controls is via a
Human Interface (HI) Panel, a standard
component of the IntelliPak chiller. This
panel provides a high degree of control.
Superior monitoring capability and
unmatched diagnostic information is
provided through a 2 line 40 character
per line, English language display.
There are no diagnostic “codes”
requiring a translation key for
interpretation. All system status
information and control adjustments
can be made from the onboard Human
Interface Panel.
Features and
(20–60 Ton)
Benefits
Remote Human Interface (RHI) — The optional Remote Human Interface (RHI)
performs the same functions as the Human Interface, with the exception of the
service mode. The RHI can be used with up to 4 air-cooled chillers from a single
panel.
The Integrated Comfort™ System — The Industry’s Most Advanced Comfort System
The UCM allows the 20 to 60-ton
IntelliPak chiller to be part of the factory
installed Integrated Comfort System
(ICS). ICS joins the Trane Tracer building
management systems and Trane HVAC
equipment by a single twisted wire
pair. This allows bidirectional
communication between the Tracer
system and the unit mounted controls.
Connected to the chiller’s UCM, this
simple pair allows you to control,
monitor, and diagnose your building’s
comfort system. The UCM is linked to
the Tracer system and they
electronically “talk” to one another.
Since ICS is factory-packaged, there is
no need to install separate sensors to
monitor your chiller’s operation. All of
the control points are on the controller
and ready to go when the unit ships.
Simply hookup the Tracer system to the
IntelliPak
pair. This feature means lower installed
cost, less chance for jobsite errors, less
design time on the front end of your
project, and fewer callbacks.
chiller with the twisted wire
ICS gives you the most powerful
monitoring and diagnostic system
available. Monitoring up to 30 individual
points, the ICS can detect and correct
problems before a comfort level change
is even noticed. Advanced monitoring
and diagnostics can help building
owners to more effectively market their
buildings to prospective tenants.
An ICS system is the most advanced
comfort system in the industry. Because
Trane has more experience with ICS
than all other equipment manufacturers
combined, you can feel secure knowing
that you are dealing with a proven track
record in building management. Trane is
the only brand that supplies the entire
package.
Tracer control points for
IntelliPak Chillers
• Chilled solution set point
• Default chilled solution set point
• Ice set point
• Default ice set point
• Chiller enable point
• Failure mode
• Ice making enable point
• KW limit enable point
• Demand limiting cooling stages
• Default number of compressors
• Design delta temperature
• Control response set point
• Reset option
7CG-PRC007-EN
Features and
Benefits
(20–60 Ton)
Trane 3-D Scroll Compressor
Simple Design with 70% Fewer Parts
Fewer parts than an equal capacity
reciprocating compressor means
significant reliability and efficiency
benefits. The single orbiting scroll
eliminates the need for pistons,
connecting rods, wrist pins and valves.
Fewer parts lead to increased reliability.
Fewer moving parts, less rotating mass
and less internal friction means greater
efficiency than reciprocating
compressors.
The Trane 3-D Scroll provides important
reliability and efficiency benefits. The 3-D
Scroll allows the orbiting scrolls to touch
in all three dimensions, forming a
completely enclosed compression
chamber which leads to increased
efficiency. In addition, the orbiting scrolls
only touch with enough force to create a
seal; there is no wear between the scroll
plates. The fixed and orbiting scrolls are
made of high strength cast iron which
results in less thermal distortion, less
leakage, and higher efficiencies. The
most outstanding feature of the 3-D
Scroll compressor is that slugging will
not cause failure. In a reciprocating
compressor, however, the liquid or dirt
can cause serious damage.
Low Torque Variation
The 3-D Scroll compressor has a very
smooth compression cycle; torque
variations are only 30 percent of that
produced by a reciprocating compressor.
This means that the scroll compressor
imposes very little stress on the motor
resulting in greater reliability. Low torque
variation reduces noise and vibration.
Suction Gas Cooled Motor
Compressor motor efficiency and
reliability is further optimized with the
latest scroll design. Cool suction gas
keeps the motor cooler for longer life and
better efficiency.
Proven Design Through Testing and
Research
With over twenty years of development
and testing, Trane 3-D Scroll
compressors have undergone more
than 400,000 hours of laboratory testing
and field operation. This work combined
with over 25 patents makes Trane the
worldwide leader in air conditioning
scroll compressor technology.
One of two matched scroll plates —
the distinguishing feature of the scroll
compressor.
Chart illustrates low torque variation of
3-D Scroll compressor vs.
reciprocating compressor.
CG-PRC007-EN8
Application Considerations
Certain application constraints should be
considered when sizing, selecting and
installing Trane air-cooled chillers. Unit
and system reliability is often dependent
upon proper and complete compliance
with these considerations. Where the
application varies from the guidelines
presented, it should be reviewed with
your local Trane sales engineer.
Note: The terms water and solution are
used interchangeably in the following
paragraphs.
UNIT SIZING
Unit capacities are listed in the
“Performance Data” section.
Intentionally oversizing a unit to assure
adequate capacity is not recommended.
Erratic system operation and excessive
compressor cycling are often a direct
result of an oversized chiller. In addition,
an oversized unit is usually more
expensive to purchase, install, and
operate. If oversizing is desired, consider
using two units.
UNIT PLACEMENT
1
Setting The Unit
A base or foundation is not required if
the selected unit location is level and
strong enough to support the unit’s
operating weight (see “Weights” section
of this catalog).
For a detailed discussion of base and
foundation construction, refer to the
Trane Reciprocating Refrigeration
Manual. Manuals are available through
the local Trane office.
2
Isolation and Sound Emission
The most effective form of isolation is to
locate the unit away from any sound
sensitive area. Structurally transmitted
sound can be reduced by using spring
isolators. Spring isolators are generally
effective in reducing vibratory noise
generated by compressors, and
therefore, are recommended for sound
sensitive installations. An acoustical
engineer should always be consulted on
critical applications.
For maximum isolation effect, water lines
and electrical conduit should also be
isolated. Wall sleeves and rubber isolated
piping hangers can be used to reduce the
sound transmitted through water piping.
To reduce the sound transmitted through
electrical conduit, use flexible electrical
conduit.
State and local codes on sound
emissions should always be considered.
Since the environment in which a sound
source is located affects sound pressure,
unit placement must be carefully
evaluated. Sound pressure and sound
power levels for chillers are available on
request.
3
Servicing
Adequate clearance for evaporator and
compressor servicing should be
provided. Recommended minimum
space envelopes for servicing are located
in the dimensional data section and can
serve as a guideline for providing
adequate clearance. The minimum space
envelopes also allow for control panel
door swing and routing maintenance
requirements. Local code requirements
may take precedence.
4
Unit Location
a
General
Unobstructed flow of condenser air is
essential to maintain chiller capacity and
operating efficiency. When determining
unit placement, careful consideration
must be given to assure a sufficient flow
of air across the condenser heat transfer
surface. Two detrimental conditions are
possible and must be avoided: warm air
recirculation and coil starvation.
Warm air recirculation occurs when
discharge air from the condenser fans is
recycled back to the condenser coil inlet.
Coil starvation occurs when free airflow
to the condenser is restricted.
Condenser coils and fan discharge must
be kept free of snow or other
obstructions to permit adequate airflow
for satisfactory unit operation.
Debris, trash, supplies, etc., should not
be allowed to accumulate in the vicinity
of the air-cooled chiller. Supply air
movement may draw debris into the
condenser coil, blocking spaces between
coil fins and causing coil starvation.
Both warm air recirculation and coil
starvation cause reductions in unit
efficiency and capacity because of the
higher head pressures associated with
them. In addition, in more severe cases,
nuisance unit shutdowns will result from
excessive head pressures. Estimates of
the degree of efficiency and capacity
reduction in such situations can be
determined. Consult your local Trane
sales engineer.
Cross winds, those perpendicular to the
condenser, tend to aid efficient operation
in warmer ambient conditions, however,
they tend to be detrimental to operation
in lower ambients or when hot gas
bypass is used due to the accompanying
loss of adequate head pressure. As a
result, it is advisable to protect air-cooled
chillers from continuous direct winds
exceeding 10 miles per hour in low
ambient conditions.
Low Ambient Operation — 20-60 Ton
models — Human Interface
Recommendations
When the temperature outside is
subzero, who wants to be out there
monitoring or troubleshooting
diagnostics? Because we understand a
service technician’s reluctance to do this,
we recommend using a Remote Human
Interface (RHI) panel. The service
technician can troubleshoot and
diagnose in the comfort of a mechanical
room.
9CG-PRC007-EN
Application
Considerations
b
Provide Vertical Clearance
Vertical condenser air discharge must be
unobstructed. While it is difficult to
predict the degree of warm air
recirculation, a unit installed as shown
below would have its capacity and
efficiency significantly reduced —
possibly to the degree of nuisance high
head pressure trip outs. Performance
data is based on free air discharge.
c
Provide Lateral Clearance
The condenser coil inlet must not be
obstructed. A unit installed closer than
the minimum recommended distance to
a wall or other vertical riser may
experience a combination of coil
starvation and warm air recirculation,
resulting in unit capacity and efficiency
reductions and possible excessive head
pressures.
The recommended lateral clearances are
depicted in the dimensional data section.
These are estimates and should be
reviewed with the local Trane sales
engineer at the jobsite.
d
Provide Sufficient Unit-to-Unit Clearance
Units should be separated from each
other by sufficient distance to prevent
warm air recirculation or coil starvation.
Doubling the recommended single unit
air-cooled chiller clearances will
generally prove to be adequate.
e
Walled Enclosure Installations
When the unit is placed in an enclosure
or small depression, the top of the fans
should be no lower than the top of the
enclosure or depression. If they are,
consideration should be given to ducting
the top of the unit. Ducting individual
fans, however, is not recommended.
Such applications should always be
reviewed with the local Trane sales
engineer.
VOLTAGE
Nominal voltage is the nameplate rating
voltage. The actual range of line voltages
at which the equipment can satisfactorily
operate are given below.
Voltage
Rated Utilization
Voltage Range
200 180-220
208-230 187-253
230 208-254
380 342-418
400 360-440
415 374-456
460 414-508
575 520-635
WATER TREATMENT
Dirt, scale, products of corrosion, and
other foreign material in the water will
adversely affect heat transfer between
the water and system components.
Foreign matter in the chilled water
system can also increase pressure drop
and, consequently, reduce waterflow.
Proper water treatment must be
determined locally and depends on the
type of system and local water
characteristics.
Do not use salt or brackish water in Trane
chillers. Use of either will lead to a
shortened life. Trane encourages the
employment of a reputable water
treatment specialist, familiar with local
water conditions, to assist in the
establishment of a proper water
treatment program.
The capacities given in the “Performance
Data” section of this catalog are based
on water with a fouling factor of 0.0001
(in accordance with ARI 550/590-98). For
capacities at other fouling factors, see
“Performance Adjustment Factors”
section of this catalog.
EFFECT OF ALTITUDE ON
CAPACITY
Chiller capacities given in the
“Performance Data” section are based
upon application at sea level. At
elevations substantially above sea level,
the decreased air density will decrease
condenser capacity and, therefore, unit
capacity and efficiency. The adjustment
factors in the “Performance Adjustment
Factors” section of this catalog can be
applied directly to the performance data
to determine the unit’s adjusted
performance.
CG-PRC007-EN10
Application
Considerations
AMBIENT LIMITATIONS
Trane chillers are designed for yearround applications in ambients from 0°F
to 115°F. For operation below 0°F or
above 115°F, contact the local Trane sales
office. If hot gas bypass is used,
operating ambients vary depending
upon unit size (see the “General Data”
section of this catalog).
1
Low Ambient Operation
Start-up and operation of Trane chillers at
lower ambient temperatures require that
sufficient head pressure be maintained
for proper expansion valve operation.
Minimum operating ambient
temperatures for standard unit selections
and units with hot gas bypass are shown
in the “General Data” section of this
catalog.
Minimum ambient temperatures are
based on still conditions (winds not
exceeding five mph). Greater wind
velocities will result in a drop in head
pressure, therefore increasing the
minimum starting and operating
ambient temperatures.
Optional low ambient units use a
electronic low ambient damper control
(20-60 tons) or a variable speed fan
motor (10-15 tons) arrangement to
control condenser capacity by
modulating condenser fans in response
to refrigerant pressure.
2
High Ambient Operation
Maximum cataloged ambient
temperature operation of a standard
Trane chiller is 115°F. Operation at design
ambients above 115°F can result in
excessive head pressures. For operation
above 115°F, contact your local Trane
sales office.
CONTROLS
1
Temperature Controller
In order to provide stable system
operation and to prevent excessive
compressor cycling, the temperature
control sensor in all 20-60 ton chillers is
located in the supply (outlet) solution.
The temperature sensor in all 10 and 15
ton chillers is located in the return (inlet)
solution. This sensor cannot be
relocated. Doing so would result in
improper unit operation.
2
Anti-recycle Timer/Fixed-Off Timer
All IntelliPak air-cooled chillers come
standard with Anti-recycle/Fixed Off
Timers. This function prevents rapid
cycling of the compressors due to low
load conditions or short water loops.
3
Pumpdown
CGAF air-cooled chillers will pumpdown,
if function is enabled, when a refrigerant
circuit is turned off. All of the refrigerant
is pumped into the condenser. A
solenoid valve provides a positive shut
off between the condenser and the
evaporator, allowing little or no
refrigerant migration to the evaporator
during “off” periods.
4
Hot Gas Bypass
Hot gas bypass provides more stable
leaving solution temperature control at
light load conditions. The compressor
runs continuously for a user-defined run
time. Minimum starting and operating
ambients with hot gas bypass are shown
in the “General Data” section of this
catalog. The hot gas bypass reduces the
unit head pressure, thereby increasing
the minimum operating ambient.
5
Loss of Flow Protection
Loss of flow may result in evaporator
freeze up. Full chilled solution flow must
be maintained through the evaporator
while compressors are operating.
A flow switch used as a safety interlock is
always recommended for CGA units.
The CGAF air-cooled chiller has a system
which senses a loss of flow condition
and shuts the unit down. A flow switch
used as a safety interlock is required for
CGAF units. A set of contacts is available
for externally starting and stopping the
pump.
WATERFLOW LIMITS
The minimum water flow rates are given
in the “General Data” section of this
catalog. Evaporator flow rates below the
tabulated values will result in laminar
flow causing scaling, stratification,
freeze-up problems, and poor
temperature control.
The maximum evaporator water flow
rate is given in the “General Data”
section. Flow rates exceeding those
listed will result in excessive tube
erosion and very high pressure drop
across the evaporator.
Trane recommends that constant water
flow be maintained at all times through
the evaporator. Because the
temperature controller strictly senses
temperature, variable flow through the
evaporator may result in loss of control
and localized freezing or nuisance low
temperature cutouts. Consult your local
Trane sales engineer if your application
requires varying flows.
TEMPERATURE LIMITS
1
Leaving Solution Temperature range
The minimum leaving solution
temperature set point is dependent on
the number of capacity stages and the
temperature difference across the
evaporator. Water supply temperature
set points less than these values result in
suction temperatures at or below the
freezing point of cold water.
A glycol solution is required for
operation below the recommended
minimum set points. Refer to the
“Performance Adjustment Factors”
section of this catalog to determine the
minimum leaving chilled solution set
11CG-PRC007-EN
Application
Considerations
point and adequate ethylene glycol
concentration for safe operation.
The maximum catalog leaving solution
temperature from the evaporator is 65°F
for outdoor ambients up to 115°F. High
leaving water temperatures exceeding
this may result in excessive suction
temperatures and, therefore, inadequate
motor cooling. For applications requiring
high leaving water temperatures, contact
your local Trane sales office for
suggested alternatives.
The maximum water temperature that
can be circulated through an evaporator,
when the unit is not operating, is
108°F (100°F for CGA 8, 10, 12½ and 15
ton chillers). The evaporator becomes
thermal stress limited at these
temperatures.
2
Supply Water Temperature Drop
The performance data for Trane chillers is
based on a chilled water temperature
drop of 10°F. Temperature drops outside
this range will result in unit performance
that differs from that cataloged. For
performance data outside the 10°F range
see the “Performance Adjustment
Factors” section in this catalog. Chilled
water temperature drops from 6 to 18°F
(8 to 12°F in CGA units) may be used as
long as minimum and maximum water
temperature and minimum and
maximum flow rates are not violated.
Temperature drops outside 6 to 18°F (8
to 12°F in CGA units) are beyond the
optimum range for control and may
adversely affect the controller’s
capability to maintain an acceptable
supply water temperature range.
Further, temperature drops of less than
6°F may result in inadequate refrigerant
superheat. Sufficient superheat is always
a primary concern in any direct
expansion refrigeration system and is
especially important in a package chiller
where the evaporator is closely coupled
to the compressor. When temperature
drops are less than 6°F, an evaporator
runaround loop may be required.
TYPICAL WATER PIPING
All building water piping must be
flushed prior to making final connections
to the chiller. To reduce heat loss and
prevent condensation, insulation should
be applied. Expansion tanks are also
usually required so that chilled water
volume changes can be accommodated.
A typical piping arrangement is shown
on the following page.
WATER VOLUME IN THE LOOP
(MINIMUM LOOP TIME)
The volume of water in the loop is critical
to the stability of system operation. The
minimum required water volume is
dependant on the chiller controller and
system GPM. Water volumes less than
the minimum required for the system
can cause nuisance problems including
low pressure trips and freezestat trips.
The cause of these trips is “Short Water
Loops”.
The minimum required water volume
(as a function of loop time and GPM) is
as follows:
CGAF: Minimum Loop Volume = GPM
x 3 Minute Loop Time
CGA: Minimum Loop Volume = GPM
X 5 Minute Loop Time
If the loop piping does not contain
enough volume, then a tank should be
added so that the equations hold true.
Generally, the more the loop volume the
greater the system stability and
controllability.
EXAMPLE: CGAFC50 with 100 gpm.
Minimum Loop Volume =
GPM x 3 Minute Loop Time
Minimum Loop Volume = 100 x 3
300 Gallon Minimum Loop Volume
If a chiller is attached to an on/off load
such as a process load, it may be difficult
for the controller to respond quickly
enough to the very rapid change in
return solution temperature. This
condition may result in freezestat or low
temperature trips. In this case, it may be
necessary to add a mixing tank in the
return line.
MULTIPLE UNIT OPERATION
Whenever two or more units are used
on one chilled water loop, Trane
recommends that their operation be
controlled from a single control device,
such as a Trane Tracer system. The
“Stand-alone” alternative is the DDC
Chiller Sequencer.
1
Series Operation
Some systems require large chilled
water temperature drops (16 to 24°F). For
those installations, two units with their
evaporators in series are usually
required. Control of the units should be
from a common temperature sensor to
prevent the separate unit controls from
fighting one another and continually
hunting. It is possible to control water
temperature from the two individual unit
controls, but a common temperature
controller provides a positive method for
preventing control overlap, more closely
matching system load and simplifying
compressor lead-lag capability.
2
Parallel Operation
Some systems require more capacity or
standby capability than a single machine
can provide. For those installations, two
units with their evaporators in a parallel
configuration are typical. The only
effective way of controlling two units in
parallel is with a single temperature
controller. For further information,
please contact Trane Applications.
CG-PRC007-EN12
Application
Considerations
10, 15 Ton
Note: Provide shutoff valves in the evaporator inlet
and outlet to facilitate water temperature sensor
removal.
20–60 Ton
Figure AC-1 — Recommended Piping Components For Typical Evaporator Installation
See unit dimensional
drawings for inlet
and outlet locations.
13CG-PRC007-EN
Selection Procedure
The chiller capacity tables presented in
the “Performance Data” section cover
the most frequently encountered leaving
water temperatures. The tables reflect a
10°F temperature drop through the
evaporator. For temperature drops other
than 10°F, fouling factors other than
0.0001 (in accordance with ARI Standard
550/590-98) and for units operating at
altitudes that are significantly greater
than sea level, refer to the “Performance
Adjustment Factors” section and apply
the appropriate adjustment factors. For
chilled brine selections, refer to the
“Performance Adjustment Factors”
section for ethylene glycol adjustment
factors.
To select a Trane air-cooled chiller, the
following information is required:
1
Design system load (in tons of
refrigeration).
2
Design leaving chilled water
temperature.
3
Design chilled water temperature drop.
4
Design ambient temperature.
5
Evaporator fouling factor.
Evaporator chilled water flow rate can be
determined by using the following
formula:
Tons x 24
GPM = Temperature Drop (Degrees F)
NOTE: Flow rate must fall within the
limits specified in the “General Data”
section of this catalog.
SELECTION EXAMPLE
Given:
Required System Load = 53 tons
Leaving Chilled Water Temperature
(LCWT) = 45°F
Chilled Water Temperature Drop = 10°F
Design Ambient Temperature = 95°F
Evaporator Fouling Factor = 0.0001
1
To calculate the required chilled
waterflow rate we use the formula:
GPM = Tons x 24
∆T
From the 60 ton unit table in the
“Performance Data” section of this
catalog, a CGAF-C60 at the given
conditions will produce 57.3 tons with a
system power input of 70.2 kw and a unit
EER of 9.8
GPM = 56.8 Tons x 24 = 137.5
10°F
2
To determine the evaporator water
pressure drop we use the flow rate
(gpm) and the evaporator water
pressure drop curves found in the
“Performance Adjustment Factors”
section of this catalog. Entering the curve
at 137.5 gpm, the pressure drop for a
nominal 60 ton evaporator is 16.5 feet.
3
For selection of chilled brine units or
applications where the altitude is
significantly greater than sea level or the
temperature drop is different than 10°F,
the performance adjustment factors
should be applied at this point.
For example:
Corrected Capacity = Capacity
(unadjusted) x Appropriate Adjustment
Factor
Corrected Flow Rate = Flow Rate
(unadjusted) x Appropriate Adjustment
Factor
Corrected KW Input = KW Input
(unadjusted) x Appropriate Adjustment
Factor
4
Verify that the selection is within design
guidelines. The final unit selection is:
Quantity (1) CGAF-C60
Cooling Capacity = 57.3 Tons
Entering/Leaving Chilled Water
Temperatures = 55/45°F
Chilled Waterflow Rate (GPM) = 137.5
Evaporator Water Pressure Drop = 16.5
ft.
System Power Input = 70.2 KW
Unit EER = 9.8
MINIMUM LEAVING CHILLED WATER
TEMPERATURE SET POINTS
The minimum leaving chilled water
temperature set point for water is listed
in the following table:
Table SP-1 — Minimum Leaving Chilled
Water Temperature Set points for Water
Evaporator Minimum Leaving Chilled Water
Temperature Temperature Set point (°F)
Difference CGAF- CGAF-
(Degrees F) C20,C25,C30 C40,C50,C60
64039
84139
10 42 40
12 43 40
14 44 41
16 45 41
18 46 42
1
These are for units without HGBP, for units with
HGBP, add 2°F to each minimum temperature in the
table.
For those applications requiring lower
set points, a glycol solution must be
used. The minimum leaving chilled
water set point for a glycol solution can
be calculated using the following
equation:
LCWS (Minimum) = GFT + 5 + ∆ T
(Evap)
# of stages of capacity.
LCWS = Leaving Chilled Water
Set point (F)
GFT = Glycol Freezing
Temperature (F)
∆ T = Delta T (the difference
between the temperature
of the water entering and
leaving the evaporator)
Solution freezing point temperatures can
be found in the Performance Data
section and the number of stages of
capacity in the General Data section. For
selection assistance, refer to the CGA
Chiller Selection program.
1
CG-PRC007-EN14
Model Number Description
10, 15 Tons
CGA 120 B 3 00 B A
123 456 7 8 9,10 11 12
DIGIT 1,2,3 — Unit Type
CGA = Air-Cooled Cold Generator
DIGITS 4,5,6 — Nominal Capacity (MBh)
100 = 8 Tons (50 Hz Model only)
120 = 10 Tons (60 Hz Model only)
150 = 12.5 Tons (50 Hz Model Only)
180 = 15 Tons (60 Hz Model Only)
DIGIT 7 — Major Design Change
(Number of Refrigerant Circuits/Number of
Compressors)
B = 2 Refrigerant Circuits/2 Compressors
™
CG A F C40 4 A A A 1 A A A A A 0 0 0 0 0 0 0 0
12 3 4 567 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
DIGIT 1,2 — Unit Model
CG = IntelliPak™ Air-Cooled Chiller
DIGIT 3 — Unit Type
A = Air-Cooled Condensing
DIGIT 4 — Development Sequence
A, B, C, etc.
DIGIT 5,6,7 — Nominal Capacity
C20 = 20 Tons
C25 = 25 Tons
C30 = 30 Tons
C40 = 40 Tons
C50 = 50 Tons
C60 = 60 Tons
DIGIT 8 — Voltage & Start Characteristics
E = 200/60/3 XL
F = 230/60/3 XL
4 = 460/60/3 XL
5 = 575/60/3 XL
9 = 380/50/3 XL
D = 415/50/3 XL
S = Special
DIGIT 9 — Factory Input
A = Standard
1. The service digit for each model number contains 25
digits; all 25 digits must be referenced.
DIGIT 8 — Voltage
1 = 208-230/60/1
(Available — CGA120 Only)
3 = 208-230/60/3
4 = 460/60/3
W = 575/60/3
D = 380-415/50/3
DIGIT 9 — Factory Installed Options
0 = No Options
H = Hot Gas Bypass
C = Black Epoxy Coil Standard Deviation
K = Hot Gas Bypass & Black Epoxy Coil
S = Special
20–60 Tons
DIGIT 10 — Design Sequence
A = First
B = Second
Etc...
DIGIT 11 — Leaving Solution Set point
A = 40-50 Deg. F w/o Ice Machine
B = 30-39 Deg. F w/o Ice Machine
D = 51-65 Deg. F w/o Ice Machine
E = 20-29 Deg. F w/o Ice Machine
1 = 40-50 Deg. F with Ice Machine
2 = 30-39 Deg. F with Ice Machine
3 = 51-65 Deg. F with Ice Machine
4 = 20-29 Deg. F with Ice Machine
S = Special
DIGIT 12 — Agency Approval
1 = UL/CSA
0 = None
DIGITS 13-25 — Miscellaneous
A = Trane Communication Interface
(TCI) Module
B = No Unit Heat Tape (50 Hz Only)
C = Compressor Current Sensing (CSM)
D = Unit Mounted Disconnect Switch
Nonfused
E = Unit Isolators Neoprene
F = Unit Isolators Spring
G = Superheat/Sub-Cooling
H = Hot Gas Bypass
DIGIT 10 — Leaving Solution Set point
0 = Standard Expansion Valve
40-60°F Leaving Water
(CGA100 & CGA120 models)
20-60°F Leaving Solution
(CGA150 & CGA180 Models)
V = Nonstandard Expansion Valve
20-39°F Leaving Solution
(CGA100 & CGA120 models)
DIGIT 11 — Minor Design Change
A = First, B = Second, etc.
DIGIT 12 —Service Digit
1
J = Generic B A S Module
(0-5 v Input, Binary Output)
M = Remote Human Interface
N = Generic B A S Module
(0-10 v Analog)
P = Remote Set point Potentiometer
Q = Zone Sensor — Chilled Solution
Reset
V = Copper Fin Condenser Coils
W = Electronic Low Ambient Damper(s)
Y = Inter-Processor Communication
Bridge (IPCB)
9 = Packed Stock Unit
The following items can be ordered for
separate shipment —
• Unit Isolators — Neoprene*
• Unit Isolators — Spring*
• Electronic Low Ambient Damper(s)
• Trane Communication Interface Module
(TCI)
• Generic B A S Module (GBAS)
• (0-5 volt Analog Input/Binary Output)
• Generic B A S Module (GBAS)
• (0-10 volt Analog Input/Output)
• Remote Human Interface
• Remote Set point Potentiometer
• Zone Sensor (Chilled Solution Reset)
• Inter-Processor Communication Bridge
(IPCB)
*Unit size must be specified when ordering
this item.
15CG-PRC007-EN
General Data
Table GD-1 — General Data — 10–60 Ton Units
10 To n 15 Ton 20 Ton 25 Ton 30 Ton 40 Ton 50 Ton 60 Ton
Model Number CGA120 CGA180 CGAF-C20 CGAF-C25 CGAF-C30 CGAF-C40 CGAF-C50 CGAF-C60
Compressor Data
Model Scroll Scroll Scroll Scroll Scroll Scroll Scroll Scroll
Quantity 2 2 2 1/1 2 4 2/2 4
Nominal Tons per Compressor 5 7.5 10 10/15 15 10 10/15 15
Evaporator
Nominal Size (Tons) 10 15 20 25 30 40 5 0 60
Water Storage Capacity (Gallons)
Min. Flow Rate (GPM) 12.0 18.0 24 30 36 4 8 60 72
Max. Flow Rate (GPM) 36.0 54.0 72 90 108 144 180 216
Max EWT At Start-Up — Deg F
Condenser
Nominal Size (Tons) 10 15 20 25 30 40 5 0 60
Number of Coils 1 2 1 2 2 2 2 2
Coil Size (ea., Inches)
4
Number of Rows 2 2 3 3 3 3 3 4
Subcooler Size (ea., Inches) 4 x 108 4 x 83 10 x 71 14 x 71 9 x 70 9 x 70 9 x 96 9 x 96
Condenser Fans
Quantity 1 2 2 3 4 4 6 6
Diameter (Inches) 28 2 6 26 26 2 6 2 6 26 2 6
CFM (Total) 8,120 11,600 15,000 21,650 29,200 29,200 42,300 40,700
Nominal RPM 1100 1100 1140 1140 1140 1140 1140 1140
Tip Speed (Ft/Min) 8060 7490 7750 7750 7750 7750 7750 7750
Motor HP (ea.) 1.0 1/2 1.0 1.0 1.0 1.0 1.0 1.0
Drive Type Direct Direct Direct Direct Direct Direct Direct Direct
Minimum Outdoor Air Temperature Permissible
For Mechanical Cooling¹
Standard Ambient Control Unit (°F) 5 0 50 3 0 3 0 3 0 3 0 30 30
Standard Ambient w/Hot Gas Bypass (°F) 6 0 60 40 40 40 4 0 40 40
Low Ambient Option (°F) 0 0 0 0 0 0 0 0
Low Ambient Control w/Hot Gas Bypass(°F) 15 1 5 10 10 10 10 10 10
General Unit
Unload Steps 10 0-50 100-50 100-50 100-60-40 100-50 100-75-50-25 100-80-60-30100-75-50-25
No. of Independent Refrig. Circuits 2 2 1 1 1 2 2 2
Refrigerant Charge (lbs. R22/Circuit) 8.25 11.5 40.5 54.0 72.0 38.0 49.0 75.00
Oil Charge (Pints/Circuit) 4.1 7.5 17.0 22.3 27.6 17.0 22.3 27.6
*Unloading steps depend upon which compressor is lead compressor.
Notes:
1. Minimum start-up ambient based on unit at minimum step of unloading and a 5 mph wind across the condenser.
2. Includes piping internal to chiller.
3. At 95°F ambient.
4. Does not include subcooling portion of coil.
²
1.4 1.5 2.2 2.7 3.2 4.1 5.0 7.4
³
100 10 0 10 8 108 108 108 108 10 8
28 x 108 28 x 83 61 x 71 45 x 71/35 x 71 56 x 70 56 x 70 57 x 96 57 x 96
CG-PRC007-EN16
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