Cable Entry / Gland Symbol
Definition: The Cable Entry / Gland symbol represents a mechanical cable entry fitting — used in wiring and installation diagrams per IEC 60617 and industrial drawing practice — that seals and anchors a cable where it passes through an enclosure wall, providing strain relief, environmental sealing, and electrical continuity of the enclosure.
Also known as: cable gland, cable entry fitting, PG fitting, strain-relief fitting, cable connector fitting.
What the Cable Entry / Gland symbol means
The Cable Entry / Gland symbol marks the point at which a cable penetrates the wall of an enclosure, panel, or junction box. It represents the mechanical fitting that grips the cable sheath, prevents the cable from being pulled out, and maintains the ingress-protection (IP) rating of the enclosure by sealing the aperture against dust, moisture, or hazardous atmospheres.
In installation and wiring diagrams the symbol indicates both a physical assembly point and a safety-critical sealing element. Engineers use it to specify the correct gland size (expressed as a metric thread such as M20 or PG16) and material (brass, stainless steel, nylon) for the cable type, environment, and hazardous-area classification (ATEX / IECEx where applicable).
How to identify the Cable Entry / Gland symbol
The cable gland symbol is drawn as a short vertical rectangle or trapezoid bisected by a horizontal line representing the enclosure wall, with a small circle or filled dot indicating the cable centreline passing through. In many CAD libraries it appears as two concentric circles connected by a short stub line, mimicking the cross-sectional view of a gland nut threaded into an enclosure. The top pin (Top) represents the incoming cable side and the bottom pin (Bottom) represents the internal termination side.
Function in a circuit
A cable gland serves three simultaneous functions in an electrical installation: mechanical retention (preventing axial pull-out of the cable), environmental sealing (maintaining the IP/NEMA rating of the enclosure), and, in armoured or screened cables, electrical bonding of the armour or braid to the enclosure earth. Selecting the wrong gland type or size compromises all three functions and can void the enclosure IP rating.
Standards: IEC vs ANSI
| IEC 60617 | IEC 60617 includes cable entry and gland representations in its mechanical/installation symbol set. IEC 62444 specifically governs cable glands for electrical installations, defining sealing, retention, and EMC bonding requirements. The symbol is typically shown as a simplified cross-section of the gland body at the enclosure boundary. |
|---|---|
| ANSI/IEEE 315 | ANSI/NEMA standards do not define a dedicated schematic symbol for cable glands; US practice typically notes the conduit hub or cable fitting on a wiring diagram as a text annotation (e.g. 'NPT 1/2" cable fitting'). IEEE 315 (ANSI Y32.2) does not list a cable gland symbol. |
| Key difference | IEC uses a graphical symbol for cable entry points in panel layout drawings; ANSI/US practice usually relies on text annotation or a generic connection point symbol rather than a distinct glyph. |
Terminals / pins
| Pin | Name |
|---|---|
| top | Top |
| bottom | Bottom |
Typical values
Metric thread sizes M12, M16, M20, M25, M32, M40, M50, M63; PG (Panzergewinde) series PG7 through PG48; cable diameter range stated in millimetres; IP rating up to IP68/IP69K; temperature range typically −40 °C to +80 °C (standard) or −60 °C to +120 °C (high-temp variants).
Where the Cable Entry / Gland symbol is used
- Control panel and switchgear enclosures — sealing power and signal cables at the entry point
- Industrial machinery — protecting cable entries on motor junction boxes and drive cabinets
- Hazardous area (ATEX/IECEx) installations — flameproof and increased-safety Ex glands for Zone 1/2 and Zone 21/22
- Outdoor and weatherproof enclosures — maintaining IP65/IP67 ratings against rain and dust
- Marine and offshore equipment — corrosion-resistant stainless or brass glands for salt-spray environments
- Building automation panels — organising and sealing low-voltage sensor and BMS cable entries
- EMC-sensitive installations — screened cable glands that bond the cable braid to the enclosure for EMC compliance
Example
In a motor control centre (MCC) panel drawing, a cable gland symbol appears at the bottom plate of each vertical section to show where the 4-core armoured supply cable enters; the symbol is annotated with the gland size (M25 A2F brass armoured gland) and cable reference, and the Top pin connects to the incoming cable tray while the Bottom pin connects to the terminal strip inside.
Key facts
- A cable gland (cable entry fitting) is a mechanical device that seals, retains, and — for armoured cables — electrically bonds a cable at the point it enters an enclosure.
- The symbol has two pins: Top (incoming cable side, outside enclosure) and Bottom (termination side, inside enclosure).
- Metric thread sizing follows IEC 62444: common sizes are M16 (small instrument cables), M20 (standard 2.5 mm² power cables), M25 (6–10 mm² cables).
- IEC 62444 and ATEX Directive 2014/34/EU (for hazardous areas) govern cable gland selection, sealing performance, and marking requirements.
- IP rating integrity of an enclosure (e.g. IP65) depends on correctly sized and torqued cable glands — an undersized gland creates a gap that fails the IP seal.
- For armoured cables, the gland must electrically bond the armour to the enclosure earth; failure to do so leaves the armour unearthed and creates a shock hazard.
- In the US, the equivalent fitting is a 'cable connector' or 'cord grip' threaded into a knockout; sizing follows NEC Article 300 and UL 514B.
Frequently asked questions
What does the cable gland symbol mean in a wiring diagram?
The cable gland symbol marks the point where a cable mechanically enters an enclosure. It represents the fitting that seals the enclosure against dust and moisture, anchors the cable against pull-out, and (for armoured cables) bonds the cable armour to the enclosure earth. It is annotated with the gland thread size and cable reference on the drawing.
What does the cable entry / gland symbol look like?
The cable gland symbol is typically drawn as a small rectangle or trapezoid bisected by a horizontal line (the enclosure wall), with a circle or short stub indicating the cable passing through. In cross-section representations it appears as two concentric rings. The top pin represents the outside (cable) side and the bottom pin represents the inside (termination) side.
What standard covers cable glands?
IEC 62444 is the primary international standard for cable glands used in electrical installations; it specifies mechanical retention, sealing, and EMC bonding requirements. ATEX Directive 2014/34/EU and IECEx govern glands used in hazardous areas. In North America, UL 514B covers cord connectors and cable fittings.
What is the difference between IEC and ANSI symbols for cable glands?
IEC documentation uses a graphical symbol for cable entry points in panel layout and installation drawings. ANSI/IEEE 315 (ANSI Y32.2) does not define a dedicated cable gland symbol; US engineering drawings typically use a text annotation or a generic entry-point marker instead.
How do I choose the right cable gland size?
Match the gland thread to the enclosure knockout (e.g. M20 thread for a standard 20 mm knockout) and select the gland clamping range to match the cable outer diameter. IEC 62444 requires that the gland pass a cable pull-out force test and maintain the specified IP rating across the full clamping range of the gland.
Why is earthing the cable armour through the gland important?
An unearthed cable armour acts as an unintentional antenna or, worse, carries fault voltage if insulation fails inside the cable. IEC 60364-5-54 requires that armour be earthed at both ends (or at one end for screens) via the gland's earth tag or integrated earth ring, providing a low-impedance fault-current return path.
What is the IP rating of a properly installed cable gland?
A correctly sized and torqued cable gland can maintain the enclosure IP rating up to IP66, IP67, or IP68 depending on the gland design and material. The IP rating is only achieved when the gland clamping range matches the actual cable diameter and the gland is torqued to the manufacturer's specification.
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