In industrial and commercial electrical systems, cable protection is critical for ensuring safety, reliability, and long-term performance. One essential component that plays a major role in cable management is the armoured cable gland. Designed specifically for armoured cables, these cable glands provide mechanical retention, environmental sealing, and electrical continuity while protecting cable terminations from damage.
Whether you work in power distribution, oil and gas, manufacturing, marine engineering, or infrastructure projects, understanding armoured cable glands is crucial for selecting the right cable management solution.
1. Definition and Purpose of an Armoured Cable Gland
An armoured cable gland is a specialized cable entry device used to securely terminate and seal armoured electrical cables when they enter electrical equipment, junction boxes, control panels, switchgear, or enclosures.
Unlike standard cable glands, armoured cable glands are specifically designed to accommodate the cable’s metallic armour layer, such as:
- Steel Wire Armour (SWA)
- Steel Tape Armour (STA)
- Aluminum Wire Armour (AWA)
- Braided Armour
Main Purposes of Armoured Cable Glands
Mechanical Retention
The gland firmly grips the cable, preventing movement, pulling, twisting, or accidental disconnection.
Armour Clamping
The gland securely terminates the cable armour, maintaining mechanical strength throughout the installation.
Environmental Protection
By creating a tight seal around the cable, the gland prevents ingress of:
- Water
- Dust
- Moisture
- Dirt
- Chemicals
- Corrosive substances
Electrical Continuity
The gland provides proper grounding and earthing of the metallic armour, helping maintain electrical safety.
Explosion Protection
In hazardous environments, specially certified armoured cable glands help prevent ignition risks and comply with safety standards.
Benefits of Using Armoured Cable Glands
- Enhanced cable protection
- Improved installation safety
- Increased system reliability
- Better strain relief
- Superior environmental sealing
- Compliance with industrial standards
2. Construction and Materials
The performance of an armoured cable gland largely depends on its construction and material selection. Manufacturers offer various materials to suit different environmental conditions and industrial requirements.
Common Materials
Brass Cable Glands
Brass is one of the most popular materials due to its excellent combination of strength, conductivity, and corrosion resistance.
Advantages:
- High durability
- Good mechanical strength
- Excellent conductivity
- Suitable for industrial environments
Nickel-Plated Brass
Nickel plating enhances corrosion resistance and improves surface hardness.
Advantages:
- Superior corrosion protection
- Better appearance
- Increased wear resistance
- Ideal for outdoor applications
Stainless Steel Cable Glands
Stainless steel cable glands are preferred for harsh and corrosive environments.
Advantages:
- Exceptional corrosion resistance
- Suitable for marine environments
- Resistant to chemicals
- Long service life
Industries:
- Offshore platforms
- Food processing
- Pharmaceutical plants
- Marine installations
Aluminum Cable Glands
Aluminum offers a lightweight solution while maintaining good strength.
Advantages:
- Lightweight
- Corrosion resistant
- Cost-effective
Plastic (Nylon) Components
Some sealing parts may utilize engineering-grade nylon materials.
Benefits:
- Lightweight
- Non-corrosive
- Economical
Typical Construction
A standard armoured cable gland generally includes:
- Gland body
- Armour clamping cone
- Armour locknut
- Sealing ring
- Compression nut
- Earth tag (optional)
- Locknut
- Shroud (optional)
Each component contributes to cable retention, sealing, grounding, and environmental protection.
3. Key Components Explained
Understanding the individual components of an armoured cable gland helps installers achieve proper termination and maximize performance.
Gland Body
The gland body serves as the main structural component.
Functions:
- Supports all other components
- Provides mounting thread
- Connects the cable to the enclosure
Armour Clamping Cone
The cone is a critical feature unique to armoured cable glands.
Functions:
- Secures the armour wires
- Ensures mechanical retention
- Maintains electrical continuity
The armour layer is positioned over the cone during installation.
Armour Clamp Ring
This component compresses the armour against the cone.
Benefits:
- Strong armour termination
- Reliable grounding
- Improved pull-out resistance
Sealing Ring
The sealing ring creates an ingress protection barrier.
Functions:
- Prevents water ingress
- Blocks dust penetration
- Protects against contaminants
High-quality seals can achieve ratings such as:
- IP66
- IP67
- IP68
Compression Nut
The compression nut tightens the seal around the cable sheath.
Functions:
- Cable retention
- Environmental sealing
- Strain relief
Locknut
The locknut secures the gland to the enclosure.
Benefits:
- Prevents loosening
- Maintains installation integrity
Earth Tag
An earth tag is often used to improve grounding connections.
Purpose:
- Provides reliable earthing
- Enhances safety
- Ensures compliance with regulations
PVC Shroud
A shroud covers the exposed gland components.
Benefits:
- Additional weather protection
- Corrosion resistance
- Improved appearance
4. Armoured Cable Gland Size Chart
Selecting the correct gland size is essential for proper sealing and cable retention.
The following chart provides general guidance.
| Gland Size | Typical Cable Diameter Range (mm) | Thread Size |
|---|---|---|
| 20S | 8 – 11 | M20 |
| 20 | 11 – 14 | M20 |
| 25S | 13 – 17 | M25 |
| 25 | 16 – 20 | M25 |
| 32 | 19 – 27 | M32 |
| 40 | 26 – 35 | M40 |
| 50S | 32 – 38 | M50 |
| 50 | 37 – 44 | M50 |
| 63S | 43 – 52 | M63 |
| 63 | 50 – 61 | M63 |
| 75S | 60 – 68 | M75 |
| 75 | 66 – 78 | M75 |
How to Choose the Correct Size
Before selecting a gland:
- Measure the cable outer diameter.
- Verify armour type.
- Check thread requirements.
- Confirm enclosure entry size.
- Consider environmental conditions.
Always consult the manufacturer’s specification sheet for exact sizing information.
5. Applications in Various Environments
Armoured cable glands are used across numerous industries where electrical systems require robust protection and reliable cable termination.
Power Distribution Systems
Applications:
- Transformer stations
- Switchgear
- Distribution panels
- Electrical substations
Benefits:
- Secure cable entry
- Reliable grounding
- Long-term performance
Oil and Gas Industry
The oil and gas sector often operates in hazardous and corrosive environments.
Applications:
- Refineries
- Offshore platforms
- Drilling facilities
- Petrochemical plants
Requirements:
- Explosion-proof certification
- Corrosion resistance
- High ingress protection
Manufacturing Facilities
Industrial plants rely heavily on armoured cable systems.
Applications:
- Production lines
- Automation systems
- Motor control centers
- Heavy machinery
Benefits:
- Mechanical protection
- Reduced downtime
- Improved safety
Renewable Energy Projects
Modern renewable energy installations frequently use armoured cables.
Applications:
- Solar farms
- Wind turbines
- Battery storage systems
Benefits:
- Outdoor durability
- Weather resistance
- Long service life
Marine and Offshore Installations
Marine environments present unique challenges due to saltwater exposure.
Applications:
- Ships
- Ports
- Offshore wind farms
- Marine control systems
Preferred Material:
- Stainless steel cable glands
Benefits:
- Corrosion resistance
- Reliability in harsh conditions
Infrastructure and Construction
Applications:
- Airports
- Railways
- Tunnels
- Commercial buildings
Benefits:
- Secure cable management
- Compliance with safety standards
- Long-term protection
6. Installation Guidelines for Armoured Cable Glands
Proper installation is critical for ensuring the effectiveness and safety of armoured cable glands.
Step 1: Select the Correct Gland
Verify:
- Cable diameter
- Armour type
- Thread size
- Environmental requirements
Using the wrong gland size can lead to sealing failure and cable damage.
Step 2: Prepare the Cable
Carefully remove:
- Outer sheath
- Bedding layers
- Armour exposure section
Avoid damaging:
- Armour wires
- Inner insulation
- Conductors
Use professional cable stripping tools whenever possible.
Step 3: Install Gland Components
Slide gland components onto the cable in the correct order:
- Compression nut
- Seal
- Armour clamping components
- Gland body
Follow the manufacturer’s assembly instructions.
Step 4: Terminate the Armour
Position the armour wires over the clamping cone.
Ensure:
- Uniform wire distribution
- Complete armour engagement
- No loose wires
Proper armour termination is essential for grounding and mechanical retention.
Step 5: Tighten the Compression Nut
Using the recommended torque:
- Tighten evenly
- Avoid over-tightening
- Verify seal compression
This step creates the environmental seal.
Step 6: Mount the Gland
Install the gland into the enclosure entry hole.
Secure using:
- Locknut
- Earth tag (if required)
- Washer (if specified)
Check alignment before final tightening.
Step 7: Verify Grounding
Inspect grounding continuity between:
- Armour
- Gland
- Enclosure
Proper grounding is essential for electrical safety and compliance.
Step 8: Final Inspection
Check:
- Seal integrity
- Armour termination
- Cable retention
- Tightness of components
- Grounding continuity
A thorough inspection helps prevent future failures and maintenance issues.
Conclusion
An armoured cable gland is far more than a simple cable entry device. It serves as a critical component that ensures mechanical retention, environmental sealing, electrical continuity, and long-term system reliability. From power plants and industrial facilities to offshore platforms and renewable energy projects, armoured cable glands provide the protection needed for demanding electrical installations.
By understanding their construction, key components, sizing requirements, applications, and proper installation methods, engineers, contractors, and system designers can select the right gland for every project. Investing in high-quality armoured cable glands not only improves safety and compliance but also reduces maintenance costs and extends the lifespan of electrical infrastructure.
For industries where reliability matters, choosing the correct armoured cable gland is an essential step toward building a safer and more durable electrical system.