Surge Protection for LED Drivers: Lightning & Transients

A lightning strike three streets away can kill a perfectly good LED driver. Surge protection is the difference between a driver that survives a storm and one that becomes e-waste — and most failures blamed on "quality" are really unprotected inputs. Here is what actually protects a driver.

Where surges come from

• Lightning — indirect strikes induce kilovolt spikes on long outdoor runs.
• Switching — contactors, lifts and big motors dump transients onto the same feeder.
• Inductive kick — even a relay opening can spike hundreds of volts.

Indoor drivers on clean building mains rarely see this. Outdoor and wet-site drivers on long cable runs see it constantly, which is why surge rating is part of the IP story, not separate from it.

The two layers that matter

How to spec for a stormy site

1. Pick a potted IP67 driver for any outdoor or coastal run — the sealed case is also the first line against moisture-driven faults.
2. Add an SPD at the feed — a Type 2 surge arrester on the distribution board feeding the lights.
3. Keep cable off the ground and away from mains where possible; parallel runs invite induced spikes.
4. Earth the enclosure properly; an un-earthed driver cannot dump a strike safely.

Common surge myths

• "IP67 means surge-proof." No — IP is water, not volts. They are separate specs; buy both.
• "One protected driver protects the string." A strike travels the cable; protect the feed, not one unit.
• "Indoor is safe." Indoor drivers on a shared feeder with lifts or compressors still see switching spikes — ask for the built-in clamp rating.

Our IP67 waterproof drivers and IP65 rainproof drivers carry internal surge clamps as standard; for exposed sites we recommend an external SPD at the supply and will size it with you.

What we need from you

Send the site (rooftop, coastal, inland), the cable run length, and whether you already have an SPD at the board. We will confirm the driver surge rating and the external protection to add.