What are Cable Glands?
Ever wondered how cables enter and exit electrical enclosures safely? The unsung hero of this process is a small yet significant component: The Cable Gland. Among these, the Single Compression Cable Gland plays a critical role. They not only allow cables to pass through safely, but they also protect against dust and moisture, ensuring the rigidity and firmness of cables. They facilitate the safe earthing of cables, underlining their significance from a safety standpoint.
These glands are devices used in electrical enclosures for the entry and exit of cables. They also serve as sealing mechanisms, preventing the intrusion of dust and moisture into the electrical enclosures. Additionally, they provide mechanical support and rigidity for the cables. From a safety standpoint, cable glands facilitate the electrical earthing of cables.
In this blog, we will focus on two main types of cable glands, the Single Compression Cable Gland and the Double Compression Cable Gland. Each has unique benefits and uses. After reading this blog, you will understand them better and be able to differentiate among them. We will explore how they function, the key differences between them, and how to choose the right one for your needs.
Single Compression Glands
Single compression glands offer compression for the cable armour in armoured cables or the cable sheath in unarmoured cables. These glands have a relatively simple design, typically consisting of a threaded body, a compression nut, and a single compression seal.
Ease of installation is one of the advantages of single compression glands; they require fewer steps compared to double compression glands. The installation process generally involves inserting the cable through the gland, tightening the compression nut, and securing the cable in place.
Single compression glands are also more cost-effective than double compression glands. While they do offer a level of ingress protection, they may be less effective at preventing the entry of dust, moisture, or other contaminants compared to double compression glands. Therefore, they are often used in indoor or low-risk environments.
These glands are suitable for applications requiring moderate ingress protection and are often selected when budget constraints are a factor.
Double Compression Glands
Double compression glands incorporate an advanced feature of two compression seals; the inner seal grips the cable jacket, while the outer seal provides an additional layer of protection against ingress.
These glands offer enhanced protection against the ingress of dust, water, oil, hazardous gases, and other contaminants. They provide an additional level of sealing compared to single compression cable glands, making them suitable for outdoor and harsh environments where superior sealing is needed.
Double compression glands offer a higher level of cable retention and strain relief. Their dual-sealing system ensures a more secure and reliable connection, reducing the risk of cable pull-out or damage. Due to their superior sealing capabilities, double compression glands are commonly used in industries such as oil and gas, marine, petrochemicals, mines, and other environments with high exposure to moisture or corrosive substances.
In a double compression cable gland, the compression is provided both at the cable armour and the inner sheath. This double sealing protects the cable against moisture, making it largely weatherproof with an IP55 degree of protection. Therefore, double compression glands are used to support heavy armoured cables.
However, these glands are typically about 30% longer and more expensive compared to single compression glands.
Choosing between a Single Compression Cable Gland and a Double Compression Cable Gland depends on the specific needs of your project/application. If you’re working in a low-risk environment or need a more general-purpose solution, a Single Compression Cable Gland can serve your needs effectively. However, if your project demands higher ingress protection, enhanced reliability, and added support for heavy-duty armoured cables, a Double Compression Cable Gland would be the preferred choice. Remember, it’s all about understanding the requirements and ensuring the selected cable gland is the best fit for your specific application.