Cable continuity in any electrical network needs cable joints. This is undertaken when you need to repair or conduct maintenance operations on the cables or you want to extend the network to include some new machine or device. We can do this jointing in many ways and the most commonly used methods are given below.
Straight through transition and other kinds of joints
The power cable jointing kits might have straight through joint or a transition type of joint. Straight through finds use in XLPE to XLPE or PILC to PILC cables. The transition type is done from XLPE to PILC cable. This type of cable jointing is useful since it gives water-tight connectivity. So, you can use the joint even underground where there is much water stagnation.
Today you can see many types of joints in use. These include the push-on joints, the pre-moulded joints, heat shrinkable type, cold application joints, and the slip-on type. You should use jointing compounds in certain instances to make an effective joint.
Heat shrink joint
The Heat shrink cable joints find use in places where there is plenty of open space. The jointing is done without the use of resins or jointing compounds. This saves much time and effort compared to the other types of cable jointing methods. The immediate energisation makes it suitable for deployment in underground cable jointing situations.
Here you take the two ends of the cable. Then, bare the wire by removing the insulation and jacket. Then, clean the wire ends and make the connection. Push the sleeve on the joint and use a blow torch to fuse the sleeve over the joint. This makes it watertight and safe. One may use this type of joints in vertical and overhead jointing of cables. Further, the jointing is small and light in weight.
Cold jointing technology
In certain situations, it may not be possible to use heat shrink methods. This is due to the restrictions placed by the authorities due to the circumstantial conditions. For instance, there may inflammable gases or liquids in the vicinity that could ignite if one uses a blow-torch. This calls for alternative methods of dealing with the situation.
So, we use cold shrink methods for cable jointing. This method has several advantages compared to the heat shrink method. First, you do not need all the special tools and permits. This eases the situation so much that the work becomes light and tension-free. Second, the time needed for the installation is less than one-third that of the heat shrink method.
This kind of jointing is possible in tight, enclosed places where you could not use a blow torch. Also, you can operate the cold shrink method when the weather conditions are not ideal. Since the method is fairly straight and simple you can teach it to your team with ease.
It is possible to use smart material in your cold shrink joint so that the seal contracts and expands with every change in the load and the temperature. So, you can expect the joint to last as long as the cable itself. Failure rate becomes lesser.