Unlocking Efficiency in Industrial Plants with Electronic Switches

Bridging the Gap Between Electromechanical Switches and Transmitters

Industrial plants everywhere still lean on electromechanical switches—workhorses that have been doing the job since the 1930s. They’re tough but they need a lot of hands‑on attention, don’t offer self‑diagnostics, and can’t keep up with today’s push for greater efficiency and data visibility. On the flip side, transmitters pack plenty of intelligence, yet their cost and complexity can be overkill for many applications. In today’s industrial technology, there is a smart middle ground that can be explored with digital electronic switches. They bring built‑in diagnostics and easy system integration—without the maintenance burden of traditional switches or the high price tag of full‑featured transmitters.

The Challenge: Aging Switch Technology

Electromechanical switches in industries like water treatment, cement, mining, and energy, remain an integral part of process instrumentation. Some 1,000 switches typically are found at large plants and at plants of average size, approximately 100.  Plants typically spend four to 12 hours annually maintaining each switch [1]. These switches:

• Offer no insight into process variable extremes
• Lack internal diagnostics
• Require frequent manual calibration and inspection

As operational demands grow, relying on these devices increasingly limits plant efficiency, uptime, and safety.

The Transmitter Trade-off

Transmitters deliver high accuracy, internal diagnostics, and long-term reliability with minimal maintenance. However, their use can be excessive in cost and effort for basic switching needs:

• 2–3× higher unit cost compared to switches
• Require additional power supplies
• Necessitate PLC reprogramming to accommodate signal changes

While transmitters are ideal for precision control, most switching applications don’t require their full functionality.

The Solution: Electronic Switches

Electronic switches—such as United Electric Controls’ Excela™—offer a modern alternative that balances simplicity with intelligence. These digital devices deliver the core benefits of traditional switches with added capabilities:

• Can be installed in existing two-wire mechanical switch infrastructure [2]
• No plant retrofitting or rewiring is needed [3]
• LCD displays and multicolor LEDs for local condition indication
• Onboard diagnostics for sensor, power, and system health
• Higher reliability with no moving parts
• Improved plant safety and reduced downtime

From a Management of Change (MoC) perspective, electronic switches require no new drawings or documents, simplifying adoption.

Configure and order the United Electric Excela™ model you need on keleindustrial.com.

Real-World Impact: Pump Monitoring in Water Treatment [4]

A municipal water treatment facility faced escalating challenges with its mechanical pump switches. These devices controlled high/low pressure alarms and shutdowns but caused frequent disruptions due to:

• High Frequency of False Alarms: Frequent spurious trips led to unnecessary pump shutdowns, hurting operational uptime.
• Lack of Visibility: Operators had no insight from the mechanical switches into process variables like inlet and outlet pressures, limiting their ability to confirm the switches were functioning properly.
• Cost Constraints: Although the facility planned to upgrade to transmitters, the cost of transmitters exceeded budget.

Solution: The facility deployed Excela™ electronic switches to monitor pump pressures. Key benefits included:

• Integrated trip filter reduced the number of spurious trips and increased operational uptime
• Integrated display and maximum/minimum values recorded allowed operators to verify pump pressure and track extreme value abnormalities
• Device self-diagnostics to alert operators to device issues and their causes
• Budget combining affordability of a switch with transmitter-like insight

The result was increased uptime, improved operational visibility, and better maintenance efficiency without the complexity or cost of a full transmitter upgrade.

Conclusion

As industrial plants modernize, the limitations of electromechanical switches become more pronounced, and transmitters often overshoot operational needs. Electronic switches offer a cost-effective, intelligent upgrade path. By leveraging existing infrastructure and minimizing change management efforts, facilities can enhance efficiency, safety, and data visibility with minimal investment.

Electronic switches bridge the gap—providing smart functionality without complexity.

References:
[1]          United Electric Controls, “White Paper – Create New Efficiency Opportunities In Industrial Plants”, ueonline.com, para. 4, 2020. [Online]. 
               Available:  https://www.ueonline.com/all-products/excela-pressure-and-temperature-electronic-switch/. [Accessed May 12, 2025).

[2]          United Electric Controls, “White Paper – Create New Efficiency Opportunities In Industrial Plants”, ueonline.com, para. 16, 2020. [Online]. 
               Available:  https://www.ueonline.com/all-products/excela-pressure-and-temperature-electronic-switch/. [Accessed May 12, 2025).

[3]          United Electric Controls, “White Paper – Create New Efficiency Opportunities In Industrial Plants”, ueonline.com, para. 18, 2020. [Online]. 
               Available:  https://www.ueonline.com/all-products/excela-pressure-and-temperature-electronic-switch/. [Accessed May 12, 2025).

[4]          United Electric Controls, “Case Study: Pump Monitoring and Control”, ueonline.com. [Online]. 
               Available:  ueonline.com/wp-content/uploads/case-sudy-excela-pump-control/. [Accessed May 12, 2025).