Installing Steel Wire Armoured (SWA) Cables: Grounding and Gland Fitting Procedures

As a UK-certified installer, I have extensive experience in the installation of Steel Wire Armoured (SWA) cables. SWA cables are widely used for their robustness and superior performance in demanding electrical applications. This guide will outline the crucial steps for grounding and gland fitting procedures to ensure your installations are secure, reliable, and meet all relevant safety standards.

Grounding SWA Cables

Grounding is a critical aspect of electrical safety, providing protection against potential hazards such as lightning strikes or electrical faults. To ground an SWA cable:

1. Select the correct ground rod: Ensure you use a suitable grounding conductor, typically copper or galvanized steel, with a minimum cross-sectional area of 6mm² for installations up to 200A.

2. Drive the ground rod: Insert the rod into moist earth at least 1m deep and spaced according to your local electrical codes or standards (typically within 10 meters from the equipment grounding point).

3. Connect the grounding conductor: Use a ferrule connector to join the end of the grounding conductor to a copper strand in the SWA cable’s outer sheath.

4. Install an earthing terminal: Connect the grounded conductor to the enclosure or equipment using a suitable earthing terminal, ensuring it is accessible and clearly marked for ease of inspection.

Fitting Glands

The gland plays a pivotal role in protecting the cable entry point and maintaining a watertight seal. When fitting glands:

1. Select the appropriate gland: Choose a gland compatible with your SWA cable size and designed for the specific application environment (e.g., indoor, outdoor, or hazardous areas).

2. Prepare the cable end: Strip back 5-10 times the cable diameter of insulation from both ends of the armour to expose the conductors.

3. Connect armour strands: Use a crimping tool to securely fasten the armour wires to the gland’s ferrule, ensuring it is properly seated and aligned with the gland’s body.

4. Solder or crimp conductor connections: Solder or crimp the individual conductives from both ends of the cable into their respective terminal screws on the gland and equipment terminations.

5. Test continuity and insulation resistance: Utilize a continuity tester to verify proper armour grounding and an insulation resistance tester to confirm adequate insulation levels before applying power.

Maintenance and Inspection

Regular maintenance is vital for long-term reliability and safety:

• Inspect cables regularly: Check for any signs of damage, wear, or corrosion at least annually or as specified by your electrical codes.
• Monitor the earth continuity: Periodically verify the integrity of the grounding system using a resistance tester to ensure it remains within acceptable limits.
• Update records: Keep detailed logs of all inspections and maintenance activities, including dates, observations, and actions taken.

FAQs

Q: What is the importance of grounding SWA cables? A: Grounding an SWA cable provides protection against potential electrical hazards such as lightning strikes or fault currents. It ensures that any excess current can be safely dissipated into the ground without causing damage to equipment or personnel.

Q: How often should I inspect my SWA cables? A: The frequency of inspections depends on several factors, including the installation environment, cable usage, and local electrical codes. As a general guideline, it is recommended to inspect SWA cables at least annually or as specified by relevant standards.

Q: Can I use any type of gland for SWA cables? A: No, it’s crucial to select an appropriate gland that matches your cable size and is designed for the specific application environment. Using incompatible glands can compromise the safety and integrity of your installation.

By adhering to these grounding and gland fitting procedures, you can ensure the safe and efficient use of Steel Wire Armoured cables in your electrical installations. Remember always to follow local electrical codes and consult with qualified professionals when necessary.

📊 CCTV System Design Reference Infographic