Blogs

A lightning protection zone (LPZ) is a defined area within or around a structure where the lightning electromagnetic environment is controlled to a specific level. IEC 62305-4 divides structures into nested zones — from LPZ 0A, where direct strike exposure is uncontrolled, to LPZ 2 and beyond, where sensitive electronics operate in a fully attenuated environment. The SPD type at each boundary depends on the threat crossing it: Type 1 at LPZ

SPD and circuit breakers protect against different threats. Learn how they coordinate, which SCPD to choose, and the correct installation order in a panel.

If you’re sourcing surge protective devices to sell under your own brand, you need an OEM SPD manufacturer who builds to your spec, ships on your timeline, and stays out of your customer relationships. That’s what OEM and ODM manufacturing means in practice — and the difference between the two affects how you structure the engagement from day one. Thor Electric manufactures IEC 61643-certified SPDs for distributors, system integrators, and electrical

Lightning arrester vs surge arrester: one intercepts direct strikes externally, the other clamps induced overvoltages inside your panels. IEC 62305-4 requires both.

How to select and wire a 3-phase surge protection device for TN-S, TT and IT systems. Type 1, 2 and 1+2 options with real parameters per IEC 61643-11.

SPD maintenance guide for industrial sites: IEC 62305 inspection schedules, fault indicator diagnosis, dry-contact monitoring, and replacement criteria.

Overvoltage damages equipment and trips systems. Learn what causes it, how transient and temporary overvoltage differ, and how SPDs protect your installation.

RS485 differential signaling resists noise but not lightning surges. Learn why, where to install RS485 SPDs, and how to select the right device.

DC surge protection devices protect EV chargers, solar, telecom and industrial DC systems. Learn how DC SPDs work, key parameters, and wiring types.

How do you choose an SPD manufacturer you can rely on? Six criteria — certifications, datasheet transparency, OEM capability, and sample readiness — that procurement teams use to qualify suppliers.

A TT earthing system (Terre-Terre) has the source neutral earthed at the transformer, while the consumer installs their own independent earth electrode on site. The fault loop impedance through that local electrode is too high for overcurrent protective devices to trip reliably — TT systems depend on RCDs for fault disconnection. Three-phase installations use four conductors from the supply, plus a local PE from the site electrode. What Is a TT

Learn what a TN-S earthing system is, how it differs from TN-C-S and TT, and how to configure your SPD correctly for TN-S installations.