Surge Arresters

Surge Arresters

Surge arresters (surge protective devices) protect electronic components in field devices by limiting or diverting overvoltage transients before damage occurs. They are engineered to address surges induced by lightning, switching events, or coupling into long cable runs - events that can silently degrade electronics even when immediate failure is not obvious.

Protection is applied across multiple pathways: signal cables (e.g., 4–20 mA), communication lines for fieldbuses (HART, PA, FF), and power lines. By safely passing surge energy into ground and using low-impedance connection concepts, protection can be achieved without introducing interference voltage drops that would compromise measurement integrity or communications quality.

Portfolio options commonly include DIN-rail mounted devices for cabinet protection and field-mount devices for protection closer to exposed instruments, with variants targeted to signal, bus, and power circuits. Optional ATEX and SIL2 intrinsically safe approvals (where offered) align surge protection with hazardous-area and safety-instrumented expectations.

Benefits are measured in availability and lifecycle protection: preventing destruction, reducing nuisance failures, and minimizing latent damage that can lead to drift, intermittent faults, or shortened electronics life. Properly selected protection - matched to the electronics involved in process automation and measuring technology - reduces downtime risk and supports more stable long-term operation.

Typical applications include process automation and measuring/communication technology within chemical, pharmaceutical, water/wastewater, and food operations, especially where field instruments are outdoors or connected via long cable routes. Strategic placement at panel entries, junction boxes, and near exposed devices strengthens resilience against recurring surge environments.

George E. Booth Co., an exclusive authorized representative of sales and service for Endress+Hauser.