The short answer
Measure the finished cable outside diameter and identify its construction, then compare those values with the exact gland manufacturer’s sealing and anchorage range. Match the entry thread and available wall thickness to the enclosure, use the specified washer, locknut or other accessories, and install to the product instructions. Treat ingress protection and strain relief as verified only for the complete documented combination—not from a gland size or IP marking alone.
1. Record the cable that will actually pass through the gland
Record the cable manufacturer and part number, construction, outside diameter tolerance, sheath material, temperature range and whether the cable is round, flat, armoured or screened. The conductor cross-section—such as 0.5mm²—does not reveal the finished outside diameter that the sealing ring grips.
Measure the production cable with a suitable method and compare the result with its current datasheet. Check more than one point if the sheath is visibly oval or irregular. Do not make a soft twin cable round by excessive compression or select a gland whose range only appears to fit after the cable is distorted.
If several cables are intended to share one entry, use only a gland or multi-hole sealing system whose instructions cover that exact arrangement. Pushing two cables through a single-hole seal does not establish sealing or anchorage.
2. Match the enclosure entry—not just the nominal thread name
Record whether the enclosure has a threaded entry or a clearance hole, the thread system and size, wall or gland-plate thickness, hole diameter and available space for a locknut and tools. CMP’s selection guidance specifically calls for the entry-hole size, enclosure wall thickness and required thread length to be checked.
Confirm the accessories required by the gland and enclosure instructions. A sealing washer, locknut, serrated washer, reducer or stopper plug is a specified component, not a decorative extra. Do not mix components from different gland systems unless the manufacturers explicitly approve the combination.
Material compatibility also belongs in the record. Consider the enclosure material, corrosion exposure, ultraviolet exposure, cleaning agents and temperature. A nylon, brass or stainless part can have different limitations even when the thread looks identical.
3. Verify sealing and cable anchorage as separate functions
HellermannTyton describes a gland as both sealing the cable entry against dust or moisture and securing the cable against pulling, bending and abrasion. Confirm the exact product’s declared IP degree, cable range and anchorage information, and the mounting conditions under which those claims apply.
An IP-rated gland cannot upgrade an unsuitable enclosure, damaged cable or unverified joint. The complete cable entry includes the enclosure wall, thread or clearance hole, washer or seal, gland body, cable sheath and any unused openings. Each part has to be installed as documented.
The gland should not be asked to carry movement that the equipment design does not allow. Plan cable support, bend control and service loops so that external loads are not transferred into the terminals. Where separate strain relief is required, show it on the drawing and inspect it independently.
4. Complete the cable-to-gland matching worksheet
Use one row for every distinct cable entry. Keep the gland datasheet and installation instruction revision with the project record; a catalogue family name is not enough for a future replacement.
| Selection input | Record | Accept when | Stop or escalate when |
|---|---|---|---|
| Cable | Part number, construction, OD and tolerance, sheath and temperature | The exact cable is within the gland’s declared range and conditions | Only conductor area or a nominal cable name is known |
| Gland | Full part number, material, seal/anchorage range and instructions | The documented range covers the production cable | The cable sits on a range boundary or the datasheet is missing |
| Enclosure entry | Thread or hole, wall thickness, material and available tool space | Thread, length and mounting method match the enclosure | An adapter or locknut is assumed but not specified |
| Accessories | Washer, locknut, reducer, shroud or stopper plug | Every required accessory is identified and compatible | Parts from unrelated systems are mixed |
| Environment | Water route, dust, UV, temperature, corrosion and cleaning | The complete assembly is suitable for the assessed exposure | An IP number is being applied to the whole sign without evidence |
| Mechanical support | Cable route, bend, support and terminal strain | The installed cable is retained without stressing the connection | Pull or movement reaches the terminal or seal |
| Inspection | Fitted part, instruction method, photographs and sign-off | The as-installed entry matches the approved record | Damage, sheath distortion or an incomplete seal is visible |
5. Worked example: use measurements as gates, not as a size shortcut
Assume a project record shows a round cable measured at 8.4mm outside diameter. A proposed gland instruction lists a 6–12mm sealing range, so the diameter check is provisionally inside range. That does not complete the selection: the record must still confirm the exact cable construction, gland anchorage range, temperature and material limits.
The enclosure drawing shows an M20 clearance entry in a 2mm panel. The team must now verify the proposed gland’s M20 thread length, maximum clearance hole, specified locknut and entry seal for that mounting method. If any one of those values is absent, the worksheet result is “unverified”—not “close enough”.
Finally, the installer follows the exact tightening method rather than a universal torque or number of turns. CMP warns against over-tightening the outer seal; use the product-specific instruction and inspect that the cable is retained without damaged or visibly distorted sheath.
6. Install and inspect without improvising the seal
Isolate the circuit and make the entry clean, correctly sized and free from burrs before fitting the gland. Follow the manufacturer’s assembly order and tightening method. Do not remove, cut, lubricate or replace a sealing ring unless the instructions explicitly require it.
Route the cable so water is not deliberately led into the entry and so the minimum bend and support requirements are respected. Do not rely on sealant wrapped around an incorrectly selected gland. Extra sealant can hide an incomplete installation and may be chemically incompatible with the cable or gland.
HSE advises checking that electrical equipment is suitable for its work and remains in good condition. Reject damaged threads, split seals, cracked bodies, abraded sheath, loose mountings or signs of overheating, and have mains-side work completed by a competent person.
7. Keep the entry record for inspection and replacement
Photograph the cable entry inside and outside before the sign is closed. Record the cable and gland part numbers, enclosure entry, accessories, installation-instruction revision and inspector. A later replacement should reproduce the approved combination rather than match only the visible thread.
During maintenance, inspect for movement, sheath creep, cracking, corrosion, blocked drainage and water tracks. De-energise before dismantling. If the cable or enclosure changes, repeat the matching worksheet because the previous gland decision no longer proves suitability.
Glowfy’s public catalogue currently includes installation cable but not a cable-gland range. Use the exact cable datasheet and the selected gland manufacturer’s instructions; contact Glowfy with the cable label and enclosure details if you need help organising the project record.
- Cable outside diameter and construction verified.
- Exact gland and accessories matched to the enclosure entry.
- Sealing, anchorage and mechanical support checked separately.
- Installation method and photographs retained.
- Any unknown result treated as unverified before energising.
Frequently asked questions
Can I choose a cable gland from the conductor size?
No. Conductor area does not give the finished cable outside diameter or construction. Match the exact cable OD and sheath data to the gland’s documented sealing and anchorage range.
Does an IP68 gland make the complete LED sign IP68?
No. The rating applies under the product’s stated conditions. The enclosure, mounting hole, accessories, cable, joints and every other entry must be assessed separately.
Is a cable gland the same as separate strain relief?
A gland may provide declared cable anchorage, but its exact capability and installation conditions must be verified. Additional cable support may still be required so movement and bending do not reach the terminals.
Should a cable gland be tightened as hard as possible?
No. Follow the exact manufacturer’s assembly and tightening instructions. Over-tightening can damage or distort the cable and seal, while under-tightening may not establish the intended retention or sealing.
Technical references
Use the current datasheet for the exact product you install. These manufacturer and standards resources explain the general principles.
Review the cable entry before fabrication
Share the cable datasheet, measured outside diameter, enclosure entry and proposed gland instructions so Glowfy can help organise the matching record.