Maintaining System Availability and Data Integrity in Industrial Automation Applications

While the integration of information technology (IT) into the operational technology (OT) realm has helped industrial organizations transition from reactive to more data-driven, predictive operations, some things remain the same. These include the need to maintain reliable, continuous operation; real-time data integrity; plant and personnel safety; and operational continuity. External power disturbances can cause automation equipment to reset or shut down. This can disrupt operations, compromise data integrity, and result in off-spec or lost product.

At the same time, when motors, pumps, drives, or other inductive equipment cycle on during normal operation in both manual and automated processes, they can pull an inrush current that is significantly higher than normal operating levels. In extreme cases, power anomalies, internal or external, can damage inadequately protected controllers and other critical automation equipment. If replacements are not immediately available from local maintenance inventories or cannot be readily sourced from a stocking distributor, costly extended production outages can result.

While battery-based uninterruptible power supplies (UPS) and/or diesel backup generators are designed to provide interim power during line power interruptions, they typically cannot react fast enough or with enough immediate energy to prevent PLCs, industrial PCs (IPCs), process controllers, edge servers, HMI panels, or other power-sensitive industrial automation equipment from resetting or shutting down.

UPSs with on-board capacitive energy storage and electronic switchover, such as Phoenix Contact's TRIO3 CAP modules (Figure 1), can provide the millisecond response and dynamic energy boosts required to avoid unintentional controller resets, shutdowns, or loss of critical data across a wide range of general-purpose industrial automation applications. This capability can maintain overall system availability and ensure safe operation until other interim power sources have time to come online, normal line power is restored, or—if absolutely necessary—the equipment can be safely shut down to preserve data.

Figure 1: Phoenix Contact’s TRIO3 capacity modules combine a 24 V_DC power supply, electronic switch-over, and energy storage in compact, DIN-rail-mountable housings. (Image source: Phoenix Contact)

Flexibility for numerous industrial automation scenarios

TRIO3 CAP industrial UPS modules provide engineers with a practical option for powering and protecting 24 V_DC DIN rail-mounted automation equipment in a wide range of facilities. These include discrete manufacturing factories; semiconductor fabs; batch, specialty chemical, and other hybrid process plants. Others involve applications in which single-phase motors, pumps, fans, and other process equipment are likely to cycle on and off frequently, creating millisecond-long voltage dips or spikes that can cause controllers or other automation devices to reset.

The TRIO3 CAP 1467800, for example, combines a 24 V_DC power supply, electronic switch-over, and supercapacitor-based energy storage in a compact 125 mm x 133 mm x 135 mm housing. With a nominal current output of five amps, the module can provide a modest dynamic power boost of 7.5 amps for five seconds and, if needed, a burst capacity boost of 17.5 amps for 350 milliseconds. Three kilojoules (kJ) of mains buffering help bridge line power failures.

The TRIO3 CAP 1467808 offers the same functionality and housing, but with increased nominal current output (10 amps), dynamic power boost (15 amps for five seconds), and burst capacity boost (35 amps for 350 milliseconds). Here, 6 kJ of mains buffering help bridge line power failures.

For more demanding automation applications with higher energy requirements, Phoenix Contact’s physically larger TRIO3 CAP 1467815 can provide a dynamic power boost of 30 amps for five seconds and, if needed, a massive burst capacity boost of 70 amps for 350 milliseconds, plus 12 kJ of mains buffering, all in a 125 mm x 249 mm x 135 mm housing.

By combining multiple functions into a single, compact, essentially maintenance-free, DIN-rail-mountable package, the TRIO3 CAP modules can significantly reduce space requirements in control cabinets, panels, and rack rooms. The dynamic power boost allows the power supply to be sized for normal operating conditions rather than peak startup demands.

TRIO3 CAP modules are suitable for use in Class I, Division 2, and Groups A, B, C, and D hazardous locations when installed in accordance with applicable requirements. Industrial packaging and a relatively wide ambient temperature range (-25°C to +60°C) mean they can be used to power automation equipment installed in cabinets inside the plant or factory, or outdoors in appropriate enclosures. This includes outdoor locations in which relatively extreme weather conditions can be expected, such as wind farms and oil and gas production fields. The modules can also be used at relatively high altitudes (up to 5,000 meters) with no performance degradation.

Connection options increase available voltage, amperage, or provide redundancy

Connection flexibility further expands applicability by providing configuration options to increase available DC output voltage and amperage. Alternatively, the modules can be connected in parallel to create 1+1 redundancy.

If an application requires more than 24 V_DC, two identically configured TRIO3 CAP modules can be connected in series (Figure 2) to provide up to 48 V_DC.

Figure 2: Connecting two identically configured TRIO3 CAP modules for series operation doubles the available voltage. (Image source: Phoenix Contact)

When extending existing systems to increase the available amperage to cover the current consumed by the most powerful load in the control cabinet or enclosure, two identically configured TRIO3 CAP modules can be connected in parallel (Figure 3).

Figure 3: Connecting two identically configured TRIO3 CAP modules for parallel operation doubles the available amperage. (Image source: Phoenix Contact)

Parallel connection can also be used to achieve 1+1 redundancy, providing a higher degree of overall system availability. Here, the DC load can be supplied by connecting two identically configured TRIO3 CAP modules in parallel using an output diode (Figure 4). Each of the modules must be able to provide the total required DC output power. In normal operation, each module will be utilized by up to 50%.

Figure 4: The addition of a diode enables two TRIO3 CAP modules to be configured in parallel operation to provide 1+1 redundancy. (Image source: Phoenix Contact)

Mitigating effects of rapid energy draws or line power sags and drops

The TRIO3 CAP’s double-layer supercapacitors provide a robust, dynamic boost function to compensate for brief overload situations, such as when a DC drive or motor starts up. When fully charged from line power, TRIO3 CAP modules can provide a dynamic boost of 150% nominal power for five seconds or a CAP boost up to 350% for 350 ms directly from their internal energy storage. The modules then recover within one minute. The double-layer supercapacitors also provide an extended (relative to lead-acid battery-based UPSs) and essentially maintenance-free 20-year service life. These characteristics are particularly relevant when powering, protecting, and backing up 24 V_DC automation equipment installed in remote or difficult-to-access locations, such as in the nodule of a wind turbine or at the top of a large tank or tower.

Should the line power drop out or the input power voltage deviate from the desired range during normal operating conditions, the modules’ capacitive energy storage can buffer these effects for several minutes, depending on current draw.

Communication interfaces provide connectivity

In today’s connected, data-driven industrial automation environment, it’s critical to avoid islanded equipment that makes it difficult to share valuable asset information with higher-level systems and software applications. In addition to front-panel LEDs that clearly display key system states, Phoenix Contact TRIO3 CAP modules include built-in communication interfaces for both USB-C (USI) and RS-485, with the USI interface having priority over the RS-485 interface.

Figure 5: TRIO3 CAP modules support RS-485 and USI/USB-C serial communications. (Image source: Phoenix Contact)

In conjunction with the appropriate software, these communication interfaces enable authorized users and applications to access condition monitoring, energy monitoring, and diagnostic data from a Windows- or Linux-based personal computer. The interfaces also provide options for securely parameterizing and controlling the modules. If necessary, authorized users can also perform a safe, controlled shutdown of industrial PCs or edge servers to save data logs.

Conclusion

Phoenix Contact TRIO3 CAP modules can provide clean, reliable power to support continuous operation and data integrity in industrial automation applications. By integrating multiple functionalities into a single, compact DIN-rail-mounted module, they simplify engineering, reduce wiring complexity and cabinet space requirements, and eliminate battery maintenance with capacitive energy storage. Built-in USB-C and RS 485 serial communications, simplified parameterization, and local or remote diagnostics further reduce engineering effort, downtime, and overall cost.