Cable Glands for EV Charging Stations: Weather Protection and Strain Relief

For outdoor EV charging equipment, reliable cable entry sealing is essential. Rain, temperature changes, UV exposure, and repeated handling can all place additional stress on the points where cables enter an enclosure. Over time, poor sealing or insufficient strain relief can allow moisture ingress or cause unnecessary wear on the cable.

At Hoonsun, we manufacture cable glands and connectors for outdoor electrical applications, including EV charging equipment. Our focus is on two basic requirements at the cable entry: maintaining a dependable environmental seal and providing enough mechanical support to protect the cable during daily use.

Choosing the right cable gland therefore involves more than matching the thread size. Cable diameter, enclosure design, IP rating, strain-relief requirements, and outdoor operating conditions all need to be considered together.

Why Cable Entry Points Matter on Outdoor EV Chargers

Outdoor EV chargers are designed to withstand rain, dust, temperature changes, and daily use, but every cable entry creates a potential weak point in the enclosure. The gland or connector at that point must maintain the seal while also supporting the cable mechanically over long periods of operation.

Several factors make these entry points especially demanding. Temperature changes can cause the air inside the enclosure to expand and contract, increasing the risk of moisture being drawn past a poor seal.

At the same time, charging cables are frequently moved, pulled, twisted, or dragged during use, which places repeated stress on the gland and cable jacket. Outdoor exposure adds another challenge, as UV radiation, moisture, salt, and airborne contaminants can gradually degrade plastics and metal surfaces.

When a cable entry begins to fail, the first signs may be subtle. Moisture ingress can lead to intermittent faults, corrosion around terminals, or nuisance tripping of protective devices. In higher-power charging equipment, even a minor sealing problem can result in downtime and additional maintenance.

Standards such as IEC 61851 define key requirements for EV charging systems, but reliable enclosure protection still depends on the components used at each cable entry. The gland must provide the required sealing level, strain relief, material durability, and mechanical stability for the actual installation environment.

For this reason, cable glands should be selected as part of the enclosure design rather than treated as a minor accessory. Cable diameter, movement, exposure conditions, thread type, and required IP rating all need to be considered before the charger goes into service.

Where Cable Glands Are Used on a Charging Station

A typical station has more cable entries than most people expect. AC units have one or two, and DC fast chargers have several, so each opening needs a gland matched to its cable and its duty.

AC inlet and power supply

The mains feed from the grid into the charger is often a heavy three-phase cable, sometimes armoured, and it hangs with real weight behind the cabinet. The gland here has to seal the jacket, clamp firmly enough to carry that weight without pulling on internal terminals, and keep the enclosure’s IP rating intact.

Our nickel-plated brass glands, like the PG16 brass waterproof gland, are a common choice for this job because the metal body resists heat and the clamping range covers typical power cable diameters.

Charging cable and connector exit

This is the entry that takes the abuse. The cable from the charger to the vehicle is pulled, coiled, and dragged across concrete every day, and the point where it leaves the cabinet is where fatigue starts. A gland with strong strain relief keeps that flex from working into the terminals, and an anti-bending design protects the jacket right at the mouth.

Chargers built as modular systems often use circular connectors with integrated sealing here, so the cable assembly can be swapped without opening the main enclosure. The connector end of that cable sees its own wear, which is why many operators keep a spare cable assembly on hand.

Control and metering enclosure

Behind the main power section there is usually a second compartment for control wiring, communication lines, and metering. These are smaller cables, often routed in bundles, and their entries are the ones most likely to be closed with a plain grommet that hardens after a few seasons. A small nylon gland costs little and seals properly, which is why we recommend treating these openings with the same care as the power side.

Selection Criteria for Outdoor Charging Infrastructure

When selecting cable glands for EV charging equipment, five factors deserve particular attention. These apply to AC charging stations, DC fast chargers, and separate charging dispensers, although the exact requirements will depend on the enclosure design and installation environment.

• IP rating and washdown requirements. IP68 is commonly specified for outdoor cable entries where protection against dust and water ingress is required, while IP65 may be sufficient for indoor or sheltered installations. Where equipment is exposed to high-pressure cleaning, a higher protection level such as IP69K may be appropriate. Always confirm the gland rating against the enclosure rating and actual site conditions.
• UV resistance. Cable glands installed in direct sunlight should use materials suitable for long-term outdoor exposure. UV-stabilized nylon is a common choice, while metal glands can provide additional durability in exposed or demanding environments.
• Temperature range. EV charging equipment can experience a wide temperature range between full-load operation and cold outdoor conditions. Both the gland body and sealing components need to remain stable across the expected operating range, so the specified temperature limits should be checked before selection.
• Strain relief. The gland clamping range should match the actual cable diameter. For cables that are moved or handled frequently, additional strain relief or an anti-bending design can help reduce stress where the cable exits the enclosure.
• Grounding and EMC. Shielded cables may require a metal EMC gland to maintain reliable contact between the cable screen and the enclosure. In charging systems that also integrate photovoltaic equipment, DC-side connections should use connectors rated for the relevant PV voltage and environmental conditions.

Selecting the gland around the actual cable, enclosure, and operating environment helps maintain sealing performance and reduces avoidable mechanical or electrical problems over the service life of the charger.

Brass, Nylon, or Stainless Steel for EV Applications

Material choice drives most of the decision, so here is the comparison we give customers when they ask. All three work, and the right answer depends on the site.

Material	Strength	Watch Out For
Nickel-plated brass	Strong clamping, dependable grounding path, good heat resistance	Heavier than nylon; plating quality matters in salt air
Nylon (PA66)	Light, corrosion-free, low cost, UV-stabilized grades available	Less rigid under heavy strain; check the temperature ceiling
Stainless steel	Best corrosion resistance for coastal and industrial sites	Highest cost; heavier; more than most inland sites need

For most charging sites, our recommendation is nickel-plated brass on the power side and UV-stabilized nylon on control wiring. Coastal stations, and sites near road salt, justify stainless or at least a higher-grade plating. Whatever the material, look for RoHS and CE compliance, and for plastic parts a UL 94 flammability rating is a sensible check.

Inspection and Maintenance We Recommend

A cable gland on a charger is a maintenance item, so these checks deserve a place in every scheduled service visit.

• Visual check of the seals: Look for cracked, hardened, or discolored sealing rings and nylon bodies. UV damage shows up first as fading, then as fine surface cracks.
• Torque verification: Gland nuts work loose from vibration and thermal cycling. Re-tighten them to the values in the datasheet during each service visit, and do not guess at the torque.
• Moisture signs: Condensation inside the enclosure, green corrosion on brass parts, or dampness along the cable jacket all mean the seal is failing. Replace the gland rather than re-sealing it.
• Cable condition at the entry: Check for flat spots, kinking, and jacket wear where the cable flexes against the gland mouth. A worn jacket lets water in even when the gland itself is intact.

Conclusion

The right cable gland depends on the cable size, enclosure rating, installation environment, and mechanical load. For outdoor EV charging applications, factors such as UV exposure, washdown conditions, and coastal corrosion should also be considered.

If you need help selecting a cable gland for an EV charging station, send Hoonsun your cable diameter, enclosure IP rating, and installation conditions. Our team can recommend a suitable model based on the application.

FAQ

Q: What IP rating should a cable gland for an EV charging station have?

A: IP68 is commonly used for outdoor EV charging equipment where dust and water protection are required. IP65 may be sufficient for sheltered installations, while pressure-washed stations may require IP69K. Always match the gland rating to the enclosure and site conditions.

Q: When is a metal cable gland needed for grounding and EMC?

A: Use a metal EMC cable gland when a shielded cable needs a reliable grounding path through the enclosure. For unshielded control cables, a standard nylon gland is usually sufficient.

Q: Can the same cable gland be used for AC and DC EV chargers?

A: Yes, provided the gland matches the cable diameter, clamping range, environmental rating, and mechanical requirements. DC fast-charging cables are typically larger and subject to more frequent handling, so stronger strain relief or an anti-bending design may be needed.