Choosing an LED Power Supply for Outdoor & Harsh Sites

"Outdoor" is not one environment. A sealed sign box in a Shopping mall canopy and a driver on a sea wall are both "outdoor", but only one of them will still be working in two years. This guide walks from the dry end to the wet end so you can pick the right unit instead of the cheapest one.

The environment ladder

Step 1: can water reach the driver?

If the driver lives inside a sealed sign box or canopy, rain runs off and nothing pools — IP65 is enough and runs cooler. If water can collect around the enclosure, step up to a fully potted IP67 unit.

Step 2: is it coastal or hosed down?

Salt spray corrodes a vented metal case from the inside. On a sea wall, in a car wash, or a food plant that gets hosed, you need silicone potting and a salt-spray test. Ask the supplier which tests were actually run, not just which number is printed.

Step 3: how hot does it get?

Sealing keeps water out but keeps heat in. A potted IP67 unit dissipates through its casing only, so size it at 70-80% of rated load in a hot, sealed space, mount it in moving air, and expect the IP67 line to stop at 400W while the vented IP65 line reaches 600W. That is physics, not a upsell.

Step 4: is it dimmed or surge-exposed?

Outdoor signs are often dimmed (0-10V for night) and surge-exposed (lightning on long runs). Pick a driver that supports your dimming standard and add an external SPD at the feed — see the dimming guide and surge guide.

Decision in one line

Dry → indoor. Rain but no pooling → IP65. Water, coastal or hosed → IP67. More than 400W outdoors → vented IP65 under cover.

Send a photo of the install location plus the load in watts and the run length. We will tell you honestly which line to buy — including when the cheaper IP65 is the right answer.