Pepperl+Fuchs has introduced a series of surge protection modules for signal, fieldbus, and Ethernet lines in process plants, including applications in hazardous areas.
The company says transient overvoltages can damage apparatus, disrupt control and automation systems, or take parts of a plant offline. It reports that operational events such as switching operations, electrostatic discharges, ground faults, and short circuits cause up to 80% of surges.
The portfolio includes DIN-rail modules, screw-terminated modules for field devices, and plug-in modules for the K-System. They are designed for hazardous areas classified as Zones 1/21 and 2/22, as well as Class I, Div. 1 and Class II, Div. 2. The F*-LB-Ex-11*7 modules screw directly onto field devices and protect two 24-V lines: either the power supply and a 24-V signal circuit, or two 24-V signal circuits. The F*-LB-Ex-1147 combines Ex(i) and Ex(d) protection in one device.
For intrinsically safe control loops and bus systems, the FS-LB-Ex-1142.PT is an energy-coordinated, two-stage surge arrester. Its low-capacitance protection circuit meets FISCO requirements and is suitable for intrinsically safe fieldbus segments using PROFIBUS PA, FOUNDATION™ Fieldbus, and HART.
Pepperl+Fuchs has also added compact surge protection barriers for Ethernet cables. The combination arresters protect against direct lightning strikes (Type 1) and indirectly coupled surges (Type 2), with Ethernet routed through RJ45 connectors. Key features include transmission class EA per ISO/IEC 11801 at frequencies up to 500 MHz; 10 Gbit/s Ethernet compatibility; an integrated status indicator and optional remote monitoring; and PoE++, 4PPoE, ATEX, IECEx, CCC, and UL support.
The M-LB-4730 is intended for retrofitting existing networks without new cabling. It supports transmission class E up to 250 MHz, Gigabit Ethernet, and PoE+, PoE++, and 4PPoE power supply standards. The M-LB-4242.HC protects a twin-conductor, ground-potential-free signal circuit with a rated current of 5 A at 24 V. Key features include a 6 mm width; a base module and tool-free replaceable protection module; a status indicator and loop disconnect function; auto-reset for uninterrupted operation; and a maximum discharge current of 20 kA (8/20 µs). The module is suitable for information technology systems, measurement and control circuits, and applications up to SIL 3 in accordance with IEC/EN 61508.
