Technical Guides

An SPD may survive a very high lightning impulse but fail during a much lower voltage that remains for seconds or longer. This longer abnormal voltage is called a temporary…

An N-PE spark gap SPD is the dedicated surge protection path installed between neutral and protective earth in many 3+1 and 1+1 arrangements. It may also be described as an…

TN-C-S SPD wiring depends first on the PEN separation point—not only on whether a product is described as 3P, 4P or 3P+N. This guide helps panel builders, electrical contractors, consultants,…

Spark gap SPD vs MOV SPD is not a simple “better or worse” comparison. A spark gap uses voltage-switching behaviour. An MOV uses voltage-limiting behaviour. This guide explains how those…

Panel Builder and OEM Engineering Guide An SPD can have a high surge-current rating and still be unsuitable for the available short-circuit current inside a distribution board or industrial control…

SPD Standards Guide for Global Buyers UL 1449 and the IEC 61643 series both address surge protective devices, but they use different classification, testing, rating and certification frameworks. This guide…

IEC 60364 Clause 534 explains how surge protective devices should be selected and installed in a low-voltage electrical installation. For a panel builder, compliance is not confirmed by writing “Type…

A pump control panel may need surge protection for more than its three-phase power supply. External level sensors, pressure transmitters, 4–20mA loops, RS485 cables and remote communication lines can also…

Network cabinet surge protection should evaluate both the AC power input and every exposed copper Ethernet or PoE line entering the cabinet. This guide is written for weak-current contractors, network…

Quick Answer An outdoor telecom cabinet normally requires more than one SPD. Protect each conductive AC, DC, Ethernet and signal line according to its actual voltage, interface, installation position and…