Choosing Cable Glands for Multicore Wires

Installing cables through enclosure walls or into electrical equipment often seems straightforward—but when multiple conductors are involved, getting the cable gland choice right becomes critical. Whether you’re sourcing components from a trusted Cable Gland Supplier or specifying a rugged Waterproof Cable Connector for industrial applications, understanding multicore cable sealing requirements is essential for long-term, reliable performance. In this guide, we walk through the key considerations you should evaluate before committing to a particular gland type or installation method. Pulte Electric Technology (Wenzhou) Co., Ltd. highlights that matching the gland to your cable configuration maintains system integrity and can help avoid water ingress and mechanical failures.

What Makes Multicore Cable Entries Challenging

Unlike single-conductor cables, multicore cables contain several insulated conductors within a single outer sheath. When these pass through a gland, you must ensure the seal adapts to both the outer diameter and the cable’s internal structure. The goal is to maintain environmental protection, mechanical strain relief, and electrical performance without damaging the cable or overcompressing the seal. Many installers underestimate how critical this balance is, which can cause compromised sealing, moisture entry, or stress on the conductors.

A multicore cable gland typically features a larger sealing area or multiple seals to accommodate the larger diameter and complexity of the cable. Some glands, such as split cable glands, allow pre-terminated cables and connectors to pass through without disassembly. These solutions offer IP66/IP68 ingress protection ratings suitable for industrial and outdoor applications while simplifying installation.

1. Size and Cable Compatibility

initial and foremost, take accurate measurements of your multicore cable’s outer diameter and compare this to the gland’s specified clamping range. A gland that’s too small won’t properly compress the sealing element, while one that’s too large won’t provide sufficient contact for sealing and strain relief, risking moisture penetration. Some glands are designed with layered or adaptable seals to handle a broader range of diameters within one product.

For multicore applications, consider these points:

Outer diameter vs. sheath shape: Some multicore cables have inconsistent diameters due to internal component spacing.

Number of cores and flexibility: A tightly packed multicore cable may require a gland with higher compression and flexible grommets.

Pre-terminated connectors: If you need to run cables with connectors already fitted, split-type glands can be a practical choice, reducing installation time while keeping sealing performance intact.

2. Environmental Protection Ratings

Ingress Protection (IP) ratings indicate how well the gland prevents dust and water entry. For multicore installations in outdoor or harsh environments, aim for glands rated IP66 or higher to ensure reliable sealing against rain, dust, and splashes. IP68 ratings signify continuous immersion protection under defined conditions, which could be crucial in marine or flood-prone environments.

Keep in mind:

Moisture and condensation: Even indoor environments can benefit from moisture-resistant glands if humidity or condensation is present.

Outdoor exposure: Glands used outdoors should also account for UV and temperature variation when selecting gland materials and sealing mechanisms.

3. Material Selection and Durability

Material choice plays a significant role in performance. Nylon glands are lightweight and economical, while brass or stainless steel options offer enhanced mechanical strength and corrosion resistance. The choice depends on environmental factors:

Stainless steel resists corrosion in coastal or chemical environments.

Brass provides solid mechanical protection and good general-purpose performance.

Plastic/nylon is suitable for standard indoor applications without extreme conditions.

In multicore configurations, heavier cables may exert greater stress on the gland body. Choosing a more durable material can help maintain sealing integrity over time and reduce the need for frequent maintenance or replacement.

4. Strain Relief and Mechanical Security

Multicore cables often carry significant weight, especially when bundled with shielding or armor. A gland must not only seal but also support the cable mechanically to prevent pull-out and stress on the conductors inside. Look for glands with robust strain relief features that maintain a secure grip on the cable sheath without causing insulation damage.

5. Installation Ease and Space Requirements

Multicore cable glands tend to be larger than those for single cables, so ensure that the installation space can accommodate the gland body and allow proper tightening. This is a frequent point of confusion for installers working within tight panel designs or compact enclosures. Pre-terminated cable glands and split designs offer an efficient fit when space is limited or when field termination is impractical.

Selecting the appropriate cable gland for multicore cables involves more than simply matching diameters—it requires careful consideration of environmental protection, material properties, mechanical support, and installation constraints. Working closely with a reputable Cable Gland Supplier and incorporating the correct Waterproof Cable Connector solutions into your system helps ensure that multicore wiring remains secure, sealed, and functional throughout its service life. Understanding these key points not only minimizes installation errors but also enhances performance and reduces costly maintenance over time.