IP68 cable glands keep water and dust out of your solar installation. Here's what to buy and where to use them.

IP68 Cable Glands for Solar: Which to Buy UK

If you're installing a plug-in solar system in the UK, one of the smallest but most important components you'll buy is the cable gland. A good IP68-rated cable gland might seem like an afterthought, but it's the seal that keeps moisture and debris out of your electrical connections — and water ingress is one of the fastest ways to kill your system.

What Does IP68 Actually Mean?

IP ratings have two digits: the first covers dust, the second covers water.

IP6 means dust-tight. Complete protection against dust ingress — nothing can get in.

IP_8 (the 8 in the second position) means immersion protection up to 1.5 metres depth. Your cable gland won't let water in even if it's submerged.

Put them together: IP68 is dust-tight and waterproof to 1.5m depth. For outdoor solar installations in the UK, that's exactly what you need. It's overkill for a rainy day, but it's ideal for cable penetrations where water could pool or debris could accumulate.

Where to Use IP68 Cable Glands

Not every cable in your solar system needs an IP68 gland — but these locations definitely do:

Wall Penetrations: If you're running cables through an external wall into your house, the hole needs sealing. An IP68 gland creates a weatherproof seal around the cable while keeping the connection accessible.

Junction Boxes: Your combiner box, DC disconnect, or AC disconnect sits outside. Any cable entry point should be sealed with an IP68 gland to prevent water pooling inside the enclosure.

Outdoor Enclosures: If you're mounting a battery (like an EcoFlow unit) or controller outside, use IP68 glands for cable entries.

Panel Connectors to First Cable Run: Some installers use glands where the MC4 connectors meet the cable, though this is less common with plug-in systems since the connectors themselves are designed to be weatherproof.

Sizing: The 6mm Solar Cable Standard

Most UK plug-in solar systems use 6mm² solar cable. Your IP68 gland needs to fit this cable diameter.

Look for glands rated M20 (6-10mm cable) or M16 (5-8mm cable) — M20 is the safer bet for 6mm² cable. The gland compresses around the cable as you tighten it, creating the seal.

Check the spec sheet carefully. A gland that's too loose won't seal; too tight and you might damage the cable insulation.

Installation Tips

Prepare the cable: Strip the outer sheath about 30mm to 50mm. Braid shielding (if present) can be carefully folded back.
Assemble dry: Thread the gland nut, then the compression ring (sometimes a conical washer), then the gland body onto the cable in that order before insertion.
Insert and tighten: Push the cable through the wall or enclosure hole, then tighten the gland nut hand-tight first. Use a wrench to snug it — don't over-torque (you're not threading a wheel).
Test the seal: Run a light spray of water across the gland entry point. No drips should appear inside the enclosure.
Use a secondary seal: Some installers apply silicone sealant around the gland nut once it's tightened. This creates a belt-and-braces approach and prevents water running down the cable into the gland.

Why Standard Cable Glands Aren't Enough

You might find cheaper cable glands rated only IP54 or IP65. These offer lower protection:

IP54 allows dust ingress and water spray protection — fine for indoor cables, not outdoor.
IP65 is dust-tight but only protects against water jets, not immersion.

In the UK, outdoor cables experience standing water from gutters, splashing from rain on pavement, and long periods of humidity. IP68 is the only rating that handles all three reliably.

What to Buy

IP68 Cable Glands are widely available for under £12 on Amazon UK. Look for brass M20 glands rated IP68. Brass is corrosion-resistant and tightens cleanly. Nylon versions are cheaper but don't tighten as reliably and can become brittle in sunlight.

A pack of 5 costs roughly the same as a single premium gland, so buy a few extra. You'll use them.

Cross-Reference

Unsure about cable sizing? Read our guide on string vs parallel wiring for plug-in solar — that'll help you understand what cables you need to run.

Summary

IP68 cable glands are cheap insurance against the UK's damp climate. They're essential at every outdoor cable penetration and take 5 minutes to install. Buy brass glands rated M20 IP68, tighten firmly (not hard), and optionally seal with silicone. Your system will thank you over the next 25 years.