Trane RTHD User Manual

Series R™ Helical Rotary
Liquid Chillers

Model RTHD
175-450 Tons (60 Hz)
125-450 Tons (50 Hz)

Built for Industrial and Commercial Applications

June 2006

RLC-PRC020-EN

Introduction

To meet a wide range of applications in
the medium-tonnage, water-cooled
market, Trane is proud to introduce the
model RTHD helical rotary liquid chiller.
The introduction of this next-generation
chiller an exciting step forward in
application versatility, ease of installation,
control precision, reliability, energy­efficiency, and operational
cost-effectiveness. The new RTHD chiller
is designed to deliver proven Series R
performance, plus all the benefits of an
advanced heat transfer design and a low­speed, direct-drive compressor.

Important Design Advances
and New Features

Major design advances include:

• Higher full-load energy efficiency
reduces both operating and life-cycle
costs.

• CH530 controls enable:

- scrolling access to inputs and operating

information via the LCD touch-screen
display;

- freedom from interoperability

concerns with LonMark
communications;

- job-specific communication options

that allow greater reporting flexibility.

• Improved startup temperature
capabilities and reduced sensitivity to
condenser water temperatures
alleviate the most common startup
concerns.

• Removed Liquid Vapor Separator,
providing lighter unit weight and
simplified refrigerant piping, for less
expensive handling, separation, and
installation.

The industrial-grade design of the Series
R helical rotary chiller is ideal for both
industrial and commercial markets, in
applications such as office buildings,
hospitals, schools, retail buildings, and
industrial facilities. The linear unloading
compressor, wide operating temperature
range, advanced controls, electronic
expansion valve, short anti-recycle
timers, and industry-leading efficiencies
mean that this latest Trane Series R chiller
is the perfect choice for tight temperature
control in almost any application
temperatures, and under widely varying
loads.

RLC-PRC020-EN© 2004 American Standard Inc. All rights reserved.

Contents

Introduction

Features and Benefits

Options

Controls

Application Considerations

Selection Procedure

Model Nomenclature

General Data

Electrical Data and Connections

Dimensions and Weights

Mechanical Specifications

Conversion Table

2

4

6

8

10

12

14

16

19

22

29

30

RLC-PRC020-EN

3

Features and
Benefits

Application Versatility and High
Performance

• Screw compressor technology and the
electronic expansion valve provide
reliable performance in an expanded
range of operating temperatures.

• Tight water temperature control extends
to operation of multiple chillers in
parallel or series configurations, offering
further system design flexibility for
maximum efficiency.

• Advanced design enables chilled water
temperature control to +/- 0.5°F (.28°C)
for flow changes up to 10 percent per
minute, plus handling of flow changes up
to 30 percent per minute for comfort
cooling.

• Two-minute stop-to-start and five-minute
start-to-start anti-recycle timer allows
tight chilled water temperature control
in constant or transient low-load
applications.

• LonMark communications capability
provides excellent, trouble-free
interoperability.

Applications in this catalog specifically
excluded from the ARI certification
program are:

• Low temperature applications, including
ice storage

• Glycol

• 50Hz units below 200 nominal tons

• Generic Building Automation System
points are available for easy access to
operational information.

• Extensive information on professional
design selection and layout is available
in a simple, highly readable electronic
format.

• Standard model RTHD configurations
are in stock and available for immediate
delivery, and Trane offers the fastest
ship cycles in the industry for built-to­order units.

• Industrial / Low Temperature Process
Cooling – Excellent operating
temperature range and precise control
capabilities enable tight control with
single chiller or series configuration.

• Ice/Thermal Storage – Specifiers and
operators benefit from dual setpoint
control and industry-leading
temperature, efficiency, and control
capabilities, plus outstanding support
through partnership with Calmac, a
strong Trane partner providing proven
installation examples, templates, and
references that minimize design time
and energy costs.

• Heat Recovery – Maximum condenser
temperature exceeds those of previous
technologies, providing hot water and
tight control that minimizes operating
costs for the chilled water plant and
boiler/hot water heater, and consistent
dehumidification.

Simple, Economical Installation

• Compact size makes the model RTHD
well suited for the retrofit and
replacement market.

• All units fit through standard double­width doors.

• Bolt-together construction makes for
fast, easy unit disassembly.

• Small RTHD footprint saves valuable
equipment room space and alleviates
access concerns for most retrofit jobs.

• Lightweight design simplifies rigging
requirements, further reducing
installation time requirements and
costs.

• Full factory refrigerant or nitrogen and
oil charges reduce required field labor,
materials, and installation cost.

• Only evaporator and condenser water
piping is required; no starter water
cooling (with its associated safety
concerns) or field piping is necessary.

• Oil cooler and purge system
connections have been eliminated.

• Simple power connection simplifies
overall installation.

• Standard unit-mounted starter for
Wye-Delta and Solid State eliminates
additional jobsite installation
considerations and labor requirements.

• Trane has conducted extensive factory
testing, and also offers options for in­person and/or documented system
performance verification.

• CH530 controls easily interface with
Tracer Summit
systems through single twisted-pair
wire.

™

building automation

Pueblo

Business Unit

RLC-PRC020-EN4

Features and
Benefits

State-of-the-Art, Precision Control

• Microprocessor-based CH530 controls
monitor and maintain optimal operation
of the chiller and its associated sensors,
actuators, relays, and switches, all of
which are factory-assembled and
extensively tested.

• Easy interface with computers hosting
Tracer Summit
energy management systems allows
the operator to efficiently optimize
comfort system performance and
minimize operating costs.

• PID (proportional integral derivative)
control strategy ensures stable, efficient
chilled water temperature control,
maintaining +/- 1°F (0.56°C) control by
proactively reacting to instantaneous
load changes of up to 50 percent.

• Adaptive Control
chiller operation under adverse
conditions, when many other chillers
might simply shut down.

• Easy-to-use operator interface displays
all operating and safety messages, with
complete diagnostics information, on a
highly readable panel with a scrolling
touch-screen display.

• The RTHD features a complete range of
chiller safety controls.

• Over 120 diagnostic and operating
points are available, with standard
displays including chiller current draw,
condenser pressure, and evaporator
pressure.

Reliability and Ease of Maintenance

• Direct drive, low-speed compressor – a
simple design with only three moving
parts – provides maximum efficiency,
high reliability, and low maintenance
requirements.

• Electronic expansion valve, with fewer
moving parts than alternative valve
designs, offers highly reliable operation.

• Suction gas-cooled motor stays
uniformly cool at lower temperatures
for longer motor life.

™

building automation/

™

attempts to maintain

• The Trane helical rotary compressor is a
proven design resulting from years of
research and thousands of test hours,
including extensive testing under
extraordinarily severe operating
conditions.

• Trane is the world’s largest
manufacturer of large helical rotary
compressors, with tens of thousands of
commercial and industrial installations
worldwide demonstrating a reliability
rate of greater than 99 percent in the
first year of operation.

Operating and Life Cycle
Cost-Effectiveness

• Electronic expansion valve enables
exceptionally tight temperature control
and extremely low superheat, resulting
in more efficient full-load and part-load
operation than previously available.

• Precise compressor rotor tip clearance
ensures optimal efficiency.

• Condenser and evaporator tubes use
the latest heat transfer technology for
increased efficiency.

• The RTHD includes standard electrical
demand limiting.

• Chilled water reset based on return
water temperature is standard.

• High compressor lift capabilities and
tight chilled water temperature control
allow highly efficient system design with
minimal operational concerns.

Design capabilities include:

• variable primary flow;

• series chiller arrangements for
evaporator and/or condenser;

• low evaporator and condenser flow.

RLC-PRC020-EN

5

Options

Insulation

All low temperature surfaces are
covered with factory installed 3/4 inch
(19.05 mm) Armaflex II or equal (k=0.28)
insulation, including the evaporator and
water boxes, suction line, and motor
housing. 3/8" foam insulation is used on
the liquid level sensor and gas pump
assembly, including piping.

Low-Temperature Evaporator

Addition of an oil cooler to the oil circuit
enables evaporator operation down to
minimum leaving water temperature of
10°F (-12.2°C).

High-Temperature Condenser

Addition of an oil cooler to the oil circuit
enables condenser operation up to
maximum leaving water temperature of
114°F (45.6°C).

Smooth-Bore Condenser Tubes

Smooth-bore copper or premium cupro­nickel condenser tubes, 3/4" (19.05 mm) in
diameter with .035" (0.889 mm) wall
thickness, are available for high fouling
water applications.

Refrigerant Isolation Valves

Factory-installed condenser inlet and
outlet refrigerant valves allow isolation of
the full refrigerant charge in the
condenser while servicing the chiller.

Marine Water Boxes

Addition of marine water boxes for the
condenser allows tube cleaning without
water pipe interference.

300 psig Evaporator and Condenser
Water Boxes

Water boxes are designed for 300 psig
maximum waterside working pressure,
and grooved pipe water connections are
provided for ease of installation.

2-Way Condenser Water Regulating Valve

For water regulation, a field-installed,
2-way butterfly-type (lug-style) valve,
with integral electrical operator and
factory-mounted valve actuator, is
available. The single-phase, reversible
motor can be factory-wired for 115 VAC,
60 Hz or 220 VAC, 50 Hz; the 2-way valve
is field-wired and controlled by the chiller
regulating valve control output; valves
are available in 6" and 8" (152.4 and

203.2 mm) sizes.

Nitrogen Charge

Unit is shipped with a nitrogen holding
charge in lieu of refrigerant.

Seal Kit for Reassembly

Ideal for situations when the bolt-together
construction of the RTHD will be
separated for installation, this seal kit
provides replacement gaskets and rings
for reassembly.

Solid State Starter

Solid State Starter is unit-mounted with a
NEMA 1 gasketed enclosure. To extend
starter life, contactors bypass current
from the silicon control rectifiers (SCRs)
after startup.

Under/Over-Voltage Protection

Unit receives protection against
variations in voltage (current lag and
spike protection is standard).

Performance and Witness Tests

ARI-certified RTHD Performance and
Witness Tests are available, based on
requested operating points, to certify
chiller performance before delivery.

Main Power Disconnect
Options:

Non-fused Disconnect

A UL-approved non-fused molded case
disconnect switch, factory pre-wired with
terminal block power connections and
equipped with a lockable external
operator handle, is available to
disconnect the chiller from main power.

Standard Interrupting Capacity Circuit
Breaker

A UL-approved standard interrupting
molded case capacity circuit breaker,
factory pre-wired with terminal block
power connections and equipped with a
lockable external operator handle, is
available to disconnect the chiller from
main power.

High Interrupting Capacity Circuit
Breaker

A UL-approved high interrupting molded
case capacity circuit breaker, factory pre­wired with terminal block power
connections and equipped with a lockable
external operator handle, is available to
disconnect the chiller from main power.

Ground Fault Circuit Breaker

A UL-approved standard interrupting
molded case capacity circuit breaker with
ground fault interrupting capability,
factory pre-wired with terminal block
connections and equipped with a lockable
external operator handle, is available to
disconnect the chiller from main power.

RLC-PRC020-EN6

Options

Control Options:

Tracer Summit Communications

Link to factory-installed, tested
communication board, via single twisted­pair wiring, adds Tracer Summit
communications to the system.

LonTalk LCI-C Interface

LonTalk (LCI-C) communications
capabilities are available, with
communication link via single twisted-pair
wiring to factory-installed, tested
communication board.

External Chilled Water Setpoint

External Chilled Water Setpoint is
communicated to a factory-installed,
tested communication board through a 2­10Vdc or 4-20mA signal.

External Current Limiting

External Current Limit Setpoint is
communicated to a factory-installed,
tested communication board through a 2­10Vdc or 4-20mA signal.

External Base Loading

External Base Loading is communicated
to a factory-installed and tested
communication board through a
2-10Vdc or 4-20mA signal.

Ice Making Control

Controls and safeties allow operation
with brine temperatures down to 20°F
(-6.7°C) , and dual setpoints enable both
ice making and daytime comfort cooling.

Programmable Relays

Default-set, factory-installed,
programmable relays allow the operator
to select four relay outputs from a list of
eight. Available relays are: Alarm­Latching, Alarm-Auto Reset, General
Alarm, Warning, Chiller Limit Mode,
Compressor Running, Head Pressure
Relief Request, and Tracer Control.

Chilled Water Reset – Outdoor Air
Temperature

Controls, sensors, and safeties allow
reset of chilled water temperature, based
on temperature signal, during periods of
low outdoor air temperature (chilled
water reset based on return chilled water
temperature is standard).

Condenser-Regulating Valve Control

Chiller applies a Proportional Integrative
Control (PID) algorithm to control water
regulating valve via 0-10Vdc signal.

Percent of Full Run Load Amps Output

Control system indicates the active chiller
percent of full run load amps, based on a
0-10Vdc signal.

Condenser Pressure Output

Control system indicates chiller
differential pressure or condenser
pressure, based on a 0-10Vdc signal.

Refrigerant Monitor Input

Control system indicates refrigerant
monitor status of 0-100 or 0-1000 ppm
(user selectable), based on a 2-10Vdc /
4-20 mA signal.

RLC-PRC020-EN

7

Controls

LCD Touch-Screen Display
with Multi-Language Support

The standard DynaView display provided
with the CH530 control panel features an
LCD touch-screen, allowing access to all
operational inputs and outputs. This
display supports eleven languages:
English, Chinese, Dutch, French, German,
Italian, Japanese, Korean, Portugese,
Spanish and Thai.

Additional Display Features Include:

• LCD touch-screen with LED backlighting,
for scrolling access to input and output
operating information

• Weather-proof enclosure for reliable
operation in non-standard indoor
environments

• Spin value buttons to allow continuously
variable setpoints when applicable

• Radio and action buttons for easy, one­time actions and settings

• Single-screen, folder/tab-style display of
all available information on individual
components (evaporator, condenser,
compressor, etc.)

• Automatic and immediate stop
capabilities for standard or immediate
manual shutdown

• Manual override indication

• Password entry/lockout system to
enable or disable display

• Fast, easy access to available chiller
data in tabbed format, including:
— Modes of operation, including normal

cooling and icemaking
— Water temperatures and setpoints
— Loading and limiting status and

setpoints
— Average line current
— Outdoor air temperature
— Start/stop differential timers
— Auto/Manual mode for EXV, slide

valve, and head pressure control
— Pump status and override
— Chilled water reset, start point, ratio,

and outdoor start point
— External setpoints, including:

- chilled water

- current limit

- ice building

- base loading

— Display specifics, including:

- date

- format

- time

- display lockout

- display units

- language setting

- Reports, listed on a single tabbed
screen for easy access, including:

• ASHRAE, containing all guideline 3

report information

• Evaporator

• Condenser

• Compressor

— Evaporator, condenser, and

compressor reports containing all
operational information on individual
components, including:

- Water and air temperatures

- Refrigerant levels, temperatures,
and approach

- Oil pressure

- Flow switch status

- EXV position

- Head pressure control command

- Compressor starts and run-time

- Line phase percent RLA, amps, and
volts

— Alarm and diagnostic information,

including:

- Flashing alarms with touch-screen
button for immediate address of
alarm condition

- Scrollable list of last ten active
diagnostics

- Specific information on applicable
diagnostic from list of over one­hundred

- Automatic or manual resetting
diagnostic types

RLC-PRC020-EN8

Controls

Trane Chiller Plant Automation

Trane’s depth of experience in chillers and
controls makes us a well-qualified choice
for automation of chiller plants using air­cooled Series R
control capabilities of the Trane Tracer
Summit
unequaled in the industry. Our chiller plant
automation software is fully pre­engineered and tested. It is a standard
software application, not custom
programming which can prove to be
difficult to support, maintain, and modify.

Energy Efficiency

Trane chiller plant automation intelligently
sequences starting of chillers to optimize
the overall chiller plant energy efficiency.
Individual chillers are designated to
operate as base, peak, or swing based on
capacity and efficiency. Sophisticated
software automatically determines which
chiller to run in response to current
conditions. The software also
automatically rotates individual chiller
operation to equalize runtime and wear
between chillers.

Trane chiller plant automation enables
unique energy-saving strategies. An
example is controlling pumps, and chillers
from the perspective of overall system
energy consumption. The software
intelligently evaluates and selects the
lowest energy consumption alternative.

Regulatory Compliance Documentation

Comprehensive documentation of
refrigerant management practices is now
a fact of life. Trane chiller plant automation
generates the reports mandated in
ASHRAE Guideline 3.

Keeping Operators Informed

A crucial part of efficiently running a
chiller plant is assuring that the
operations staff is instantly aware of
what is happening in the plant. Graphics
showing schematics of chillers, piping,
pumps, and towers clearly depict the
chiller plant system, enabling building
operators to easily monitor overall
conditions. Status screens display both
current conditions and upcoming
automated control actions to add or
subtract chiller capacity. Series R
other chillers can be monitored and
controlled from a remote location.

®

chillers®. The chiller plant

®

building automation system are

™

and

Tracer Summit features standard report
templates listing key operating data for
troubleshooting and verifying
performance. Reports for each type of
Trane chiller and three and six-chiller
systems are also standard. Detailed
reports showing chiller runtimes aid in
planning for preventative maintenance.

Swift Emergency Response

We understand the importance of
maintaining chilled water production
while protecting your chillers from costly
damage. If no water flow is detected to a
chiller’s piping, the start sequence is
aborted to protect the chiller. The next
chiller in the sequence is immediately
started to maintain cooling.

In the event of a problem, the operator
receives an alarm notification and
diagnostic message to aid in quick and
accurate troubleshooting. A snapshot
report showing system status just prior to
an emergency shutdown helps operators
determine the cause. If emergency
conditions justify an immediate manual
shutdown, the operator can override the
automatic control.

™

Integrated Comfort

Capabilities

When integrated with a Tracer Summit
building management system
performing building control, Trane chiller
plant automation coordinates with Tracer
Summit applications to optimize the total
building operation. With this system
option, the full breadth of Trane’s HVAC
and controls experience are applied to
offer solutions to many facility issues. If
your project calls for an interface to other
systems, Tracer Summit can share data
via BACnet

™

, the ASHRAE open systems

protocol.

LonTalk Chiller Controls

LonTalk is a communications protocol
developed by the Echelon Corporation.
The LonMark association develops
control profiles using the LonTalk
communication protocol. LonTalk is a unit
level communications protocol, unlike
BACNet used at the system level.

LonTalk Communications Interface for
Chillers (LCI-C) provides a generic
automation system with the LonMark
chiller profile inputs/outputs. In addition to
the standard points, Trane provides other
commonly used network output variables
for greater interoperability with any
automation system. The complete
reference list of Trane LonTalk points is
available on the LonMark website. Trane
controls or another vendor’s system can
use the predefined list of points with ease
to give the operator a complete picture of
how the system is running.

Hardwire Points

Remote devices wired from the control
panel are another reliable method of
providing auxiliary control to a building
automation system. Inputs and outputs
can be communicated via a typical 4-20
mA electrical signal (or an equivalent Vdc
signal of 0-10 or 2-10) or by utilizing
contact closures.

• External Chilled Water Setpoint

• External Current Limit Setpoint

• Condenser-Regulating Valve Control

• Percent of Full Run Load Amps Output

• Condenser Pressure Output

• Refrigerant Monitor Input

• Programmable Relays
Allows the selection of 4 relay outputs
from a list of eight different default
settings: Alarm-Latching, Alarm-Auto
Reset, General Alarm, Warning, Chiller
Limit Mode, Compressor Running, Head
Pressure Relief Request, and Tracer
Control. These contact closures may be
used to trigger jobsite supplied audible or
visual alarms

• Ice Making Control
Provides an interface with ice making
control system and safeties, enabling
both ice making and daytime comfort
cooling

• Chilled Water Temperature Reset
Supplies controls, sensors and safeties to
reset the chilled water temperature
setpoint based upon return water
temperature (standard) or outdoor air
temperature (optional)

RLC-PRC020-EN

9

Application
Considerations

Condenser Water Temperatures

Reduced sensitivity to condenser water
startup temperatures is one major
enhancement in the newest-generation
water-cooled Series R chiller. With the
model RTHD chiller, a condenser water
control method is necessary only if the
unit starts with entering water
temperatures below 55°F (12.8°C), or
between 45°F (7.2°C) and 55°F (12.8°C),
when a temperature increase of 1°F
(0.56°C) per minute to 55°F (12.8°) is not
possible.

When the application requires startup
temperatures below the prescribed
minimums, a variety of options are
available. To control a 2-way or 3-way
valve, Trane offers a Condenser
Regulating Valve Control option for the
CH530 controls. This option enables the
CH530 controls to send a signal for
opening and closing the valve as
necessary to maintain chiller differential
pressure. The 2-way valves are available
as a ship-with option. Tower bypass is
also a valid control method if the chiller
temperature requirements can be
maintained.

Trane Series R chillers start and operate
successfully and reliably over a range of
load conditions with controlled entering
condenser water temperature. Reducing
the condenser water temperature is an
effective method of lowering chiller

power input required, but the ideal
temperature for optimizing total system
power consumption will depend on the
overall system dynamics. From a system
perspective, some improvements in
chiller efficiency may be offset by the
increased tower fan and pumping costs
required to achieve the lower tower
temperatures.

Contact your local Trane
systems solution provider for more
information on optimizing system
performance.

The minimum acceptable refrigerant
pressure differential between condenser
and evaporator is 23 psid. The chiller
control system will attempt to obtain and
maintain this differential at startup, but for
continuous operation a design should
maintain a 25°F (13.9°C) differential from
evaporator leaving water temperature to
condenser leaving water temperature.

Variable Evaporator Flow and Short
Evaporator Water Loops

Variable evaporator flow is an energy­saving design strategy which has quickly
gained acceptance as advances in chiller
and controls technology have made it
possible. With its linear unloading
compressor design and advanced CH530
controls, the RTHD has excellent
capability to maintain leaving water
temperature control within +/-0.5°F
(0.28°C) , even for systems with variable
evaporator flow and small chilled water
volumes.

Some basic rules should be followed
whenever using these system design and
operational savings methods with the
RTHD. The proper location of the chilled
water temperature control sensor is in
the supply (outlet) water. This location
allows the building to act as a buffer, and
it assures a slowly changing return water
temperature. If there is insufficient water
volume in the system to provide an
adequate buffer, temperature control can
be lost, resulting in erratic system
operation and excessive compressor
cycling. To ensure consistent operation
and tight temperature control, the chilled
water loop should be at least two
minutes. If this recommendation cannot
be followed, and tight leaving water
temperature control is necessary, a
storage tank or larger header pipe should
be installed to increase the volume of
water in the system.

For variable primary flow applications,
the rate of chilled water flow change
should not exceed 10 percent of design
per minute to maintain +/-0.5°F (0.28°C)
leaving evaporator temperature control.
For applications in which system energy
savings is most important and tight
temperature control is classified as
+/-2°F (1.1°C), up to 30 percent changes in
flow per minute are possible. Flow rates
should be maintained between the
minimum and maximum allowed for any
particular chiller configuration.

RLC-PRC020-EN10