Technical Guides

Quick Answer Does a sensor line need surge protection? A sensor line needs a surge-risk check when it runs outdoors, between buildings or over a long distance. These cable routes…

Outdoor SPD Buyer Guide This outdoor SPD IP rating guide explains when an IP20 DIN-rail surge protective device can be installed inside an IP65 enclosure, when a separate outdoor surge…

Industrial Automation Engineering Guide A reliable factory automation surge protection plan must protect every conductive path into the control system—not only the incoming AC supply. This industrial automation surge protection…

BESS DC-Side Engineering Guide Selecting a BESS DC SPD is not the same as selecting a solar PV SPD. The battery circuit can present different fault-current, grounding and end-of-life conditions.…

SPD Engineering, Site Inspection and OEM Selection Guide A low earth-resistance reading is helpful, but it does not by itself prove that an SPD has an effective surge-current path. Engineers…

SPD Installation Guide for Panel Builders SPD cable length directly affects the protection delivered inside a completed distribution board. A surge protective device may have a low declared Up, but…

SPD Structure and OEM Selection Guide MOV and GDT are both used for surge protection, but they operate differently. An MOV progressively limits voltage. A GDT or spark gap remains…

Type 1 SPD Engineering and OEM Guide Published: July 14, 2026 Technical review: LEEYEE SPD Engineering Team Standards reviewed: IEC 61643-11:2025 and IEC 61643-12:2020 When a project already requires a…

Single-Phase SPD Buyer & OEM Selection Guide The difference between a 1P+N SPD and a 2P SPD cannot always be determined from the product name. For a correct single-phase distribution-board…

TN-S System · Three-Phase Distribution · OEM Selection TN-S SPD Wiring at a Glance In a three-phase TN-S system, the surge protective device is connected in parallel with L1, L2,…