Surge Arresters

Surge Arresters

Surge arresters (overvoltage protectors) are protection devices designed to prevent electrical transients from damaging instrumentation electronics. Overvoltage events can originate from direct or indirect lightning strikes and from switching operations within industrial power and control infrastructure. Even brief disturbances can disrupt production, so surge protection is used to improve availability by preventing device failures and nuisance downtime.

These devices work by diverting surge energy safely to ground, protecting the connected electronics while keeping normal measurement and communication behavior intact. They are applied not only to power conductors, but also to signal cables (including 4…20 mA loops) and to communication lines used in process automation networks such as HART and fieldbus systems. A low-impedance connection path is emphasized to avoid introducing interference voltage drops during normal operation.

Portfolio options typically include DIN-rail models for control cabinets, field-mount variants installed closer to the instrument, and specialized protectors for signal, communication, and power lines. Approvals and functional options may include intrinsically safe (ATEX) and SIL-oriented variants, aligning surge protection strategy with hazardous-area and safety-instrumented requirements.

Benefits include increased plant availability and reduced replacement/repair costs for sensitive electronics in transmitters, gateways, and I/O cards. Because surge arresters are specified to match the characteristics of process automation and measurement electronics, they can provide robust protection without compromising signal transparency or communication performance when properly selected and installed.

Typical applications include measurement and communication technology in process industries such as chemical, pharmaceutical, water and wastewater, and food production. Installation planning should coordinate grounding quality, bonding strategy, and placement (cabinet entry points, marshalling, and field junctions) so that surges are intercepted before reaching vulnerable devices. Periodic inspection practices and clear replacement procedures help maintain protection integrity over time.

Engineered Equipment Company, a leading supplier of specialized industrial equipment.