Cable jointing is one of the basic parts of an electrical network. The need to make the joint arises when we need to repair the cable or we need to extend the cable to facilitate its use for another purpose. For making the cable joint, we need to make the connections first.
Keep the number of cores same
There are several electrical connection requirements that one must fulfil to make a connection. The connection is then sealed over in different methods to make the joint watertight and weatherproof. These would be heat shrink, cold shrink, slip-on, and so on. The first requirement is that the number of cores of the cable that we join is equal to that of the one that it is joining.
Heat shrink joint
For making heat shrink cable joints one uses the heat shrink sleeve. This is put on at the site of the joint such that it slips over one end of the cables and rests. The wires are bared and joined and then the heat sleeve is brought over the joint. Now, heat is applied in the form of a torch. The heat helps to shrink the sleeve over the joint and this makes the joint tight and waterproof. This method is useful when the site is open and there is place to use the torch. Further, the application should be safe for heat treatment.
Use of cold shrink cable joint
One cannot use this method when there is inflammable gas or fuel around. In those cases, a cold shrink joint is used. One can also use a slip-on type of joint since it does not involve open fire. In the cold shrink joint, the sleeve tightens on the joint when it is released. The slip-on type has a sleeve that gets fixed on top of the joint by tension. The sleeve is pre-tensed so that when it is released on top of the joint, it snaps into place and becomes airtight.
Electrical connection requirements
The other conditions that must be met include those related to voltage carried in the cables, the current rating, the use of proper conductors, check for insulations, and more. The types of connection used for wires include soldered connections, crimp connection, wire-wrapping connection, eye connection (otherwise known as the loop connection), and direct connection. The factors that determine the usage will be these.
Outdoor or not
If the use is for outdoor, the material must be tough and durable. They need to have the resilience to last long and serve the need. Similarly, the voltage needs are satisfied by making the connections separate for low-voltage, medium-voltage and high-voltage power supply. One must use the proper joint for the voltage otherwise the low-voltage joint will fail when applied to a high-voltage circuit.
Types of joint
The kind of joint needed must be right. This tells how we make the joint. The simplest is the straight-through joint where the two cables are joined at some point while the other connections carry on to other points in the circuit. Thus, you might have one or more advanced branch connections in the circuit.
Use of the proper jointing methods is needed to keep the circuit safe and functional. Always follow the norms laid down. Do not compromise on safety.