Top 10 SPD manufacturers: how to compare them
Compare the top 10 SPD manufacturers by product scope, standards and OEM options, and check any supplier’s IEC 61643 claims before you buy.
Blogs
Is Surge Protection Necessary? What the Standards Require
Is surge protection necessary? See how IEC 60364 and the applicable national standard determine when an SPD is required and when omission is permitted.
What a TVS Diode Does Inside a Surge Protection Device
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: How to Size an SPD
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: IEC 62305 in 5 Steps
Lightning protection system design to IEC 62305: risk assessment, protection level, rolling sphere radii, down conductors and where SPDs belong.
SPD Thermal Stability: Safe Failure Explained
SPD thermal stability explained: what a thermal test checks, how thermal overload protection works, and why a disconnected SPD must be replaced.
How to Test a Surge Protection Device (and Why a Multimeter Isn’t Enough)
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 Explained: Which Part Applies to Your SPD
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.