Just as in the consumer market, industrial control technology is rapidly evolving. Equipment manufacturers are pushing technological limits of performance in order to meet the economic goals of a nimble marketplace. From the inclusion of more complex and energy efficient components to fully integrated communication options, chiller control technology has advanced significantly over the past decade.

Bombarded with both new technologies and evolving equipment, you might find it difficult to evaluate and select the right control package for specific applications or facilities. It is extremely important to understand both the environment within which the equipment will be installed as well as the intended chiller application.

Operators of process cooling equipment continue to place increasingly tough demands on their chillers and associated equipment. Recent advances in chiller control systems have enabled improved levels of efficiency and performance, allowing smaller units to provide equivalent cooling loads, and/or serving even wider temperature ranges.

System controls must be able to simplify the complex data into actionable data so that operators can quickly interpret and make the appropriate adjustments. Equipment and control design must take into consideration the changing face of today’s workforce. Today’s users may be more savvy with electronics, but are required to service more than just one system or piece of equipment. Controls need to be intuitive and provide the right data to ensure continued efficient operation.

Chiller Performance Control

Newer equipment employs a great deal of energy efficient components. From the inclusion of variable frequency drives (VFDs) for tighter motor control to the replacement of electromechanical contactors with solid-state relays (SSRs), systems become more complex.

Whereas a dusty operational environment may not have been an issue with previous chiller installations, newer equipment requiring cooling fans for VFDs and SSRs may become clogged and require regular attention. Ignoring such issues may cause premature failure and expensive service calls. It is imperative that chiller controls are savvy enough to inform users when such issues are identified.

As equipment performance is pushed to the edges of its capabilities, additional monitoring is required in order to protect both the chiller and the process. The control platform must be able to compute complex algorithms and evaluate hundreds of system parameters to not only ensure the equipment is running at the peak of efficiency based upon the given load, but also serve to protect the components from premature failure. The number of sensors and collected data points has significantly increased, requiring an understanding of communication wiring and its relationship to power wiring. Previous chiller designs that may have been susceptible to any number of failure types are being obsoleted for these more efficient, and more sensitive, product designs.

Operator Usability

Regardless of the complexities surrounding the internal functioning of the chiller, actual equipment usability is critical to ensure the system meets the specific needs of the application. Today’s operators are influenced by the ever-changing consumer electronics market.

As a critical decision point, it is important to understand the human machine interface (HMI) platform being offered with the equipment. Initial system setup needs to be extremely simple and operators need to intuitively understand how to make setpoint adjustments on the fly. Key performance parameters should be visible and historical machine data points need to be easily accessible. Performance trend data needs to be collected and displayed in order to understand not only the performance of the equipment over time, but the impact system changes may have on the operational efficiency of the equipment. 

Beyond user control directly at the equipment, control systems must be able to be accessed from any location. Logging directly into the equipment to not only review performance, but to also make adjustments based upon load characteristics is a critical feature of new control sets. Accessing equipment from desktop computers, tablets, or even smartphones allow for remote monitoring, troubleshooting, and even equipment self-diagnosis.

By understanding the unique characteristics of a particular installation, today’s controls can inform equipment owners about maintenance items that must be conducted in order to ensure continued efficient operation. Owners may then be proactive in scheduling downtime versus being reactive to a problem that causes unplanned shutdowns.

System Scalability

The terms “plug-and-play” and “point-and-click” have embedded themselves into the daily lexicon of both consumer and industrial life. Once the mechanical installation of new equipment is complete, the expectation is that the remaining requirements for full system startup should be extremely quick and easy.

Complex wiring or in-depth software changes can add significant labor time for any new equipment installation or application expansion. Today’s controls need to adhere to the plug-and-play mindset by simplifying the expansion of an existing chilling system or significantly improving the speed of initial startup. One-wire connection and simplified menu screens for startup are a must for any new chiller.

Beyond the installation and system startup requirements, a process cooling application must also be able to meet the monetary needs of the business. Although a current facility may have a three-year expansion plan, the current chilling requirements may call for only one smaller chiller. Chilling systems must be extremely scalable so that additional cooling capacity can be added to the system without requiring a great deal of production disruption or complex installation.

For example, a facility that requires 100 tons of cooling today, but is planning for an additional 200 tons of cooling within the next 36 months, should not have to purchase a 300-ton chiller today just to meet future requirements that may indeed change. The organization should be able to purchase an appropriately sized chiller for the current demand, and then purchase additional chillers as needed to coincide with the expansion in production, so as to match the expense to the planned growth. System controls need to be able to handle this type of scaling capability with ease.

Effective Redundancy

Any manufacturer understands that the production of acceptable products directly translates to sales dollars. During the system evaluation process, it is necessary to understand the requirements for full system redundancy. Production downtime is both extremely expensive and time consuming.

Modular chilling systems can provide additional redundancy while balancing the load requirements for the most efficient operation of the chilling system as a whole. For a 300-ton installation, three 100-ton modular systems installed in a master/drone configuration can ensure greater efficiency at lower production loads and allow for 100% effective redundancy with the addition of one more 100-ton module. Instead of purchasing a full 300-ton chiller as a backup in case of failure or disruption, a much lower-cost 100-ton chiller can provide all of the redundancy necessary to ensure continued operations.

When considering the controls of a modular system, it is also important to understand the theory of operations for each of the chiller modules. In a master/drone configuration, are the controls of the system resident with just the master module, or can each of the drones operate regardless of the status of the master module? Each unit should have the capability to operate and provide chilled fluid to the production floor regardless of the status of a separate module.

Just as important is the operation of the human machine interface. Should the HMI fail, the ability to access the system parameters and ensure continued operation should exist. When considering such a configuration, it is also important to understand the operational considerations when switching lead compressors.

Complexity & Service

The reality of newer chiller technologies is that systems have become significantly more complex. With additional data points and sensors, plus the inclusion of variable frequency drives for energy management, users must have a better understanding of more than just the process cooling application. 

Understanding the power situation of the facility becomes significantly more important. Controls are susceptible to issues such as electromagnetic/radio-frequency interference, transient voltages, ground loops, and improper grounding. Such issues may have already existed within the system previously, but older equipment may not have been impacted by such issues.

Today’s manufacturing environment is such that the equipment must remain nimble and as efficient as possible. This requires more sensitive equipment that better monitors and controls the process cooling application based upon the load. These more sensitive systems may then respond to facility issues that were previously hidden by the continued operation of older equipment. In exchange for more accurate and energy efficient equipment, users may have to better understand the issues within the facility to ensure efficient operation of all production equipment.

During the chiller equipment selection process, the right sales and engineering partnership can guide you through the process. The selection of the right equipment with the associated control platform will significantly enhance your overall user experience.

About the author… Tim Hallett is currently product manager for all water-related products offered through the ACS Group, bringing extensive product management experience to the ACS team. He has over 15 years of experience in marketing and product management for highly technical products offered to the industrial and HVAC markets.