9.Sketch the device which allows a cable to pass through a watertight bulkhead, labelling the MAIN components.(10)
Watertight electric cable gland
A watertight electric cable gland is a device designed to seal the entry point where an electrical cable passes through a bulkhead, panel, or enclosure, ensuring that the connection remains watertight and protects the electrical components from moisture, dust, and other environmental contaminants.
Key Features and Construction:
- Body: The main body of the gland is typically made of brass, stainless steel, or nylon, providing strength and corrosion resistance.
- Clamping Mechanism: A clamping mechanism, usually a set of internal grips or a compression ring, securely grips the cable’s outer sheath to provide strain relief and prevent any movement or pulling on the internal connections.
- Sealing Elements: Multiple sealing elements, such as O-rings or compression seals, are used to create a watertight barrier around the cable and prevent any moisture ingress.
- Cable Entry: The gland has a threaded entry point for the cable, allowing for secure and adjustable fitting of various cable diameters.
- Lock Nut: A lock nut is used to tighten the gland against the bulkhead or enclosure, ensuring a firm and watertight seal.
Types of Watertight Cable Glands:
- Single Cable Glands: Designed for sealing a single cable entry.
- Multi-Cable Glands: Allow for multiple cables to pass through a single gland, simplifying installation and reducing the number of penetrations.
- Armored Cable Glands: Specifically designed for use with armored cables, providing additional protection and grounding.
- EMC Cable Glands: Offer electromagnetic compatibility (EMC) shielding to prevent interference from electromagnetic radiation.
Applications:
- Marine: Widely used on ships and boats to protect electrical systems from the harsh marine environment.
- Outdoor and Industrial: Used in outdoor installations, industrial equipment, and any other applications where electrical connections need to be protected from moisture, dust, or other environmental factors.
Benefits:
- Watertightness: Prevents water and moisture from entering the electrical enclosure or equipment, protecting sensitive components from damage and corrosion.
- Strain Relief: Provides strain relief for the cable, preventing any pulling or stress on the internal connections.
- Environmental Protection: Protects against the ingress of dust, dirt, and other contaminants that could affect the electrical system’s performance.
- Safety: Ensures the safety of personnel by preventing electrical shocks or short circuits caused by moisture ingress.
Installation:
- Proper Selection: Choose the correct size and type of gland based on the cable diameter and the application requirements.
- Secure Mounting: Ensure the gland is securely mounted to the bulkhead or enclosure using the lock nut and appropriate sealing washers.
- Cable Preparation: Prepare the cable by stripping the outer sheath and any armoring to the correct length for insertion into the gland.
- Tightening: Tighten the gland’s clamping mechanism to securely grip the cable without damaging it.
- Testing: After installation, test the gland’s watertightness using a low-pressure hose or other suitable method.
By using watertight cable glands, electrical installations can be protected from the damaging effects of moisture and other environmental factors, ensuring their reliability and longevity in demanding applications.