Taking a digital approach to switchgear maintenance and safety

Safety first. Nearly all modern industrial operations prioritize a continuous focus on safety to help reduce risks, avoid injuries, and support efficient and safe operations. Today, digital tools are helping advance and simplify these efforts.

Traditionally, industrial organizations have applied digitalization to immediate challenges such as combating a lack of skilled workers and supply chain issues. It’s far less common for industrial digital transformation to focus on energy and power systems, although digitalization enabled by IIoT and predictive analytics can make it easier and faster to maintain equipment. This has created an environment where early adopters stand to gain a significant competitive advantage (see Figure 1). 

The digital transformation of foundational infrastructure used in industrial operations to distribute power—namely, switchgear—delivers new capabilities that will help enhance safety. Armed with data-driven insights from the switchgear and circuit breakers, maintenance teams can reduce their time near (and exposure to) energized equipment, which means less risk. Further, continuous monitoring enabled through equipment digitalization means that maintenance staff can predict and prevent problems that would otherwise cause downtime or equipment damage. 

1. Speed matters: Quenching an arc

Three factors impact the severity of an arcing event: available power, and the distance to and duration of a fault. New engineering controls can be designed into your electrical system using arc quenching technology, minimizing the duration of a fault and taking it out in under 4 milliseconds or about one quarter of a cycle, which is an order of magnitude faster than traditional technologies. 

With traditional arc-resistant equipment, which is designed to redirect arc energy away from people, downtime can last for weeks or months until the equipment is replaced after an event. Arc quenching switchgear both limits damage to the equipment and contains the event away from people (see Figure 2). When the relay detects an arc fault inside of the gear, it sends a signal to the arc quenching device, which produces a lower impedance arc fully contained inside an arc containment vessel located within the arc quenching device. The lower impedance arc collapses the voltage and immediately extinguishes the arcing fault as the current begins to flow into the arc quenching device.

2. Continuous thermal monitoring identifies problems in real time 

Traditionally, maintenance staff conduct infrared (IR) scans of switchgear during regular maintenance, which can be on an annual or even three-year cycle, depending on environmental conditions and the process itself. When the IR scan indicates an issue, trained staff need to open the switchgear cabinet to investigate. 

Digitalization enables a fundamentally different approach, shifting away from in-person IR scans and toward continuous thermal monitoring that provides always-available data. When there’s an issue, an automated alert will inform staff of a problem and when equipment needs servicing. In other words, there’s no need to wait for the annual (or three-year) maintenance scan because you can identify a problem when it’s developing. People do not need to perform time-intensive scans on equipment that does not need to be serviced, which reduces unneeded safety risks and proximity to energized systems. Instead of searching for a problem, team members can be alerted when they need to focus on fixing a specific problem to prevent downtime. (That said, in the event of an alarm, needed maintenance should be addressed in real time.)

3. Always-on data insights into electrical equipment health

New data from the circuit breaker trip units, switchgear meters, and protective relays can provide a comprehensive view into equipment health that can be used for predictive maintenance and improving system reliability. For example, specific insights from circuit breaker trip units include: 

• Operational data shows when a circuit breaker mechanism was last exercised and if the mechanism was bound or jammed. 
• The total number of operations can provide indication of the endurance wear on a circuit breaker mechanism and indication of contact wear. 
• The number of interruptions and the magnitude of the energy interrupted provide vital parameters to the contact wear and arc chute condition. 
• The magnitude of short-circuit events, which can be damaging to the contacts, integrity, and dielectric strength of the circuit breaker, can be compared to the rating of the circuit breaker and weighed as a factor in the health of the device. 
• The environmental temperature, especially temperature highs, which are recorded and date/time stamped for future analysis.

4. Easy access to test reports

Digitalization of switchgear and circuit protection means there’s far more ready access to testing data, which removes guesswork when plant managers establish maintenance programs. For example, plant and maintenance teams can now retrieve original manufacturer factory test reports through apps available on a cell phone to new secondary injection testing capabilities. Enabled by electric trip units, secondary injection testing allows a user to verify settings and alarm setpoints programmed into the trip units. In other words, this immediately extinguishes the arcing fault as the current begins to flow into the arc quenching device; electronic trip units can verify the complete integrity of the connections, sensing circuitry, microprocessor and the circuit breaker mechanics.

Moving toward predictive and preventative maintenance practices 

A digital approach to switchgear maintenance can help reduce walk-through time and electrical exposure through detailed forensic data and set alerts. In other words, you can keep personnel informed without putting people in front of energized equipment (and within the arc flash boundary). Further, you can enhance safety and reduce costs by avoiding unnecessary, calendar-based maintenance practices. Instead, staff can be alerted to problems in real-time, and they can spot energy usage anomalies, potential vulnerabilities, and adjust equipment parameters and cybersecurity settings. 

Importantly, a digital approach to switchgear maintenance delivers long-term power and energy usage information that’s needed to make smarter capital investment decisions. IIoT is an enabler to presenting data to cloud and edge storage systems, and you stand to gain a competitive edge by leveraging that data to improve the efficiency of your operations.