Blogs

A TVS diode is the fast clamping stage of an SPD, not the whole device. See how a published signal SPD circuit stages its protection.

Surge protection for LED street lights, from an SPD maker: why drivers fail, how to read Uc, In, Imax and Up, and where the device goes on the pole.

Lightning protection system design to IEC 62305: risk assessment, protection level, rolling sphere radii, down conductors and where SPDs belong.

SPD thermal stability explained: what a thermal test checks, how thermal overload protection works, and why a disconnected SPD must be replaced.

Learn how to test a surge protection device, what a multimeter actually confirms, the insulation-test mistake most guides get wrong, and when to replace.

IEC 61643 is a family, not a single standard. Find out which part covers AC, DC, PV and signal SPDs, and what the 2025 edition of Part 11 changed.

Most SPD datasheets lead with the biggest number on the page, and for a Type 2 device that number is usually Imax. Of all the SPD parameters printed on the sheet, it is close to the least useful one for comparing products. IEC 61643-01:2024 lists Imax at item 28 of its marking and information list, worded “if declared by the manufacturer”, while item 6 requires a Type 2 SPD to declare In in

Verify a surge protection device certificate against its model, ratings, test report and issuing database before placing an order.

How a lightning protection system works end to end: IEC 62305 zones, air terminals, earthing, and the SPDs that limit surges reaching your equipment.

How does a lightning conductor work? Follow the current from the rooftop air terminal through bonding and down conductors to earth.

Solar DC SPD connection diagram done right: parallel PV+/PV- to earth, U-type vs Y-type, where to install it, and the lead-length rule that matters.

Choose industrial surge protection by voltage, SPD type, installation point and surge rating, with IEC 61643-11 product examples.