In different industries, such as offshore, nuclear, mining, and substations, we find extensive use of cables and their accessories. These accessories must have the capacity to withstand extreme weather conditions and rough handling.
Choose from different accessories
These could be either overhead or underground installations and if the power cable accessories have good quality, they will withstand rigorous conditions and deliver reliable service. Choice of the best accessories is needed since this is the way to guarantee a long life. The insulation material of the cables must be able to withstand erosion and tracking and the effects of environmental stresses. One could classify these into four main categories as:
- Low voltage terminations
- Medium voltage terminations
- High voltage terminations
- Extra high voltage terminations
Other than these, one also sees the link boxes. One can do the testing for the cable joint and terminations by accessing the shield breaks provided along with. This also helps limit the sheath voltage build up. This type of voltage build up can happen due to switching operations, fault currents, and lightning.
Tools used during the cable jointing
One uses various types of tools for the cable jointing and repairing process. These would include the stripping tool and the cable repair sleeves for starters. Depending on the situation one may need to use one or more of the following tools:
- Cable entry glands
- Cable cutting tools
- Cable end caps
- Cable spiker tools
- High voltage insulation tool box
Low voltage terminations
The insulation in low voltage terminations usually consist of gels, resin, and heat shrink techniques. The method of use is quick and easy. You will be able to use it in all cable applications. Reinstatement and energisation is also immediate. The straight and branch joints less than 1kV use this cable jointing method.
Medium voltage terminations
This uses reliable technologies under the most severe service conditions. They use polymeric and paper cables able to withstand high thermal, environmental, mechanical, and electrical stress. In this case, they use both heat and cold shrink technologies. The installation used is quick, reliable, and easy. You can use a variety of connection methods and a wide range of conductors.
High voltage terminations
The high voltage terminations are used in the 69kV, 72kV, and 84kV transmission voltages. One can use prefabricated joints and terminations in the 145 – 170 kV range. It can be used in transformers and switchgears in the outdoor and indoor applications. The cross-bonding is provided by the link boxes and can be used for all polymeric cables. Another option is the mechanical lugs and connectors. Use is made of elastomeric and heat shrink technologies. External grounding options along with shield break are provided.
Extra-high voltage terminations
This type of joint is applicable for transmission voltages below 245kV. This one piece is pre-fabricated with different designs in the polymeric insulated cables. The choice of the metal sheath and shielding offers the options in design. The electric function is assured through the stress control by geometric integration of the body made of silicone rubber. This is factory tested. The assembly is simple with a moulded screen on the outer side that is thick.
The cable joint and jointing technique is chosen according to the industry and situation. Use of high quality material and tools ensures high quality service delivery.