Cable joints or terminations form an integral part of the electrical distribution network system. They come into play when one needs to elongate an existing cable or needs to make a joint, in order to add a new length of cable. Usually, this takes place when the old cable has undergone damage.
Common tools used in terminations
Many tools come into use for making cable terminations. These include cable insulation remover, cable sheath jacket stripper, cable strippers, and semi-conductive screens, among others. Here we look at medium voltage cable terminations.
Types of cable splices
We have many methods of doing the cable splice.
- Heat shrink
- Cold shrink
Properties of each type of jointing method
Tape: This is a universal method and you can use it for practically anything. Use the tape to splice any cable regardless of the size. You have many commonly stocked products in this. However, it takes a longer time for installation as one has to apply the tape to the entire splice. Moreover, the strength and quality of the tape splice depends on the craftsmanship.
Push-on: This needs lesser time than the tape splice. Usually you use a factory tested splice body. However, this has more drawbacks than benefits. For one, you need a special connector. You cannot use this for all types of connections. You must have enough space to park the connector. You need to know the cable construction type before doing the push-on. Moreover, you will find it difficult to install this on large cables. One has to use asymmetrical cutbacks to do the push-on.
Heat shrink: The heat shrink method needs less effort and time than a tape splice. In addition, one can use it for more applications than there are for the push-on splice. Among the minus points, you see one needs a torch. This involves use of fire and therefore you need a fire hazard permit. One should have enough space on the cable to park the splice. One must have familiarity with the cable types. While applying the heat, you must do it uniformly.
Cold shrink: This has the widest applicability among cable splices. It keeps up the pressure on the connector and the cable. The effort required for this installation is the least. You can use this cold shrink splice in all weather conditions. In addition, you do not require a torch. However, you must know the cable construction type and you need enough space to park your splice.
Criteria for selection of the type of splice to use
The main selection criteria include reliability, worker safety, and value and cost of the life cycle. Other than these, you have many other considerations such as voltage class and cable type for starters. Then you have fault duty, grounding, and bonding requirements.
One must take into consideration the complexity of the instructions along with the complexity of the installation. Customer standards and the industry standards play an important role. Then, you have to consider the environment and installation variables. Obviously, you can use different installation methods.
We find that cable joints, cable terminations, and cable splices fail often. Upon investigation, the reason usually will include the careless workmanship of the cable splicer or cable jointer.