The four main components of a vapor compression refrigeration cycle chiller are the compressor, the condenser, the evaporator and the expansion valve. It is important to make sure that these components are high-quality and robust for long-term reliable operation.

However, too often a fifth component, which is the absolute key to well-orchestrated, optimized operation and lower operating costs is underestimated or overlooked - the controls!

Let’s have a closer look at what makes up a chiller control system, why it is important, and specific features that can help you achieve the most efficient operation and the lowest operating costs.


What makes up a chiller control system?
A chiller requires both hardware and software to operate, to keep running even during the most challenging conditions, and to protect all the other components in the event of any alarm (abnormal behavior leading to a warning or a fault).

A user interface displays real-time chiller data including any alarms, to allow the user to take action.

In addition to the hardware and software, a chiller has a sophisticated network of strategically placed temperature, pressure and flow
sensors connected to the circuits, which send critical information to the controller and interpreted in real-time to continuously adjust the chiller’s operation. Inverter driven maglev compressor adds more closed-loop control parameters for chiller controller to be act upon.

Why is a chiller control system critical?
The chiller control system contributes to
- Chiller performance
- Chiller efficiency and reliability
- Building performance and efficiency
- Serviceability
- Unit connectivity

What control system is Trane using on Trane Sintesis Excellent and XStream Excellent chillers*?
To reach best in class chiller performance, enhanced building performance and efficiency, enhanced serviceability and unit connectivity, Trane chillers are equipped with a powerful proprietary combination of state-of-the-art controls.

Trane owns the full design of our controller (hardware and software), which gives unit level benefits compared to chiller manufacturers using third party PLC and their own control algorithms.

Hardware: Trane Symbio™ 800 controller is a new generation controller allowing seamless communication with other Trane equipment in the chiller plant. It is designed and optimized based on experiences of hundreds of thousands of Trane installations around the world, in normal and extreme conditions.
The Symbio 800 is the industry’s first application-specific and field-programmable controller – providing more flexibility and customizable operation sequences.

Software: Trane Adaptive Control™ algorithms integrated in Trane’s proprietary control software keep the chiller running even during the most challenging conditions, when other chillers should shut down. This includes rapid restart after power failure capabilities for applications such as data centers.

User interface: Interfacing with the chiller is user friendly and fast thanks to the full color touchscreen user display, Tracer™ TD7.
• Expanded security, user access control and user interaction audit logs
• BACnet event logs, schedules, trends and alarm management
• SD card backup/restore
• Multiple communications options (BACnet/IP, BACnet/MSTP, Modbus RTU, Modbus TCP, and LonTalk) for seamless connection to building automation systems.
• Trane Connect Remote Service ready
• Wi-Fi option
This powerful combination features:
• Guarantee of superior reliability and lowest cost of ownership.
• Adaptive controls to endure smooth operation and optimal performance.
• Advanced algorithms for smarter and more reliable operations.
    o e.g.: Free cooling, mix mode and mechanical cooling mode are automatically enabled to ensure the highest possible efficiency whatever the operating conditions for air-cooled unit with free-cooling.
• Advanced flexibility with I/O expandability via expansion modules allow side loop and ancillary equipment control via custom programming
• Rapid Restart – Simultaneous dual circuit start
• IP connectivity and the ability to generate segregated alarms
• Faster response to BMS commands than other controllers - this was proven when a GVAF was installed on a test loop beside competition chiller for controls comparison.
• Unlocked full potential of a connected unit with full remote monitoring capabilities.

Trane can also advise on Chiller Plant Control implementation to further increase efficiency and adapt the application to customer needs.

* and other Trane chillers and heat-pumps

Learn more about Trane’s chiller controllers
Learn more about Sintesis Excellent GVAF
Learn more about XStream Excellent GVWF