Blogs

To decide what size MCB for SPD protection to use, start with the SPD manufacturer’s coordination table: select the listed breaker series, current rating and trip curve, then check its breaking capacity against the installation’s prospective short-circuit current. A 32 A or 63 A breaker is a result of that selection. The SPD’s surge rating, such as 40 kA, cannot be converted into an MCB amp rating. First check whether an

EV charger surge protection: what IEC 60364 asks for, how exposure decides Type 1+2 or Type 2, and why the SPD needs its own bonding connection.

The types of earthing systems: IEC 60364’s three families and five arrangements, TN-S, TN-C, TN-C-S, TT and IT, and how each constrains SPD connection.

Compare the top 10 SPD manufacturers by product scope, standards and OEM options, and check any supplier’s IEC 61643 claims before you buy.

Is surge protection necessary? See how IEC 60364 and the applicable national standard determine when an SPD is required and when omission is permitted.

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