Construction of Power Cable

Construction of Power Cable

There are various parts of a cable to be taken care of during construction. The power cable mainly consists of:

1. Conductor
2. Insulation
3. LAY for Multicore cables only
4. Bedding
5. Bedding
6. Outer Sheath

                                                                 

Conductor:

Conductors are the only power carrying path in a power cable. Conductors are of different materials. Mainly in cable industry we use copper (ATC, ABC) and aluminum conductors for power cables. There are different types of conductor as Class 1: solid, Class 2 stranded, Class 5 flexible, Class 6 Extra flexible (Mostly used for cords and welding) etc. Conductor sizes are identified with conductor resistance.

Insulation:

The insulation provided on each conductor of a cable by mainly PVC (Poly Vinyl Chloride), XLPE (Cross-linked Polyethylene), RUBBER (Various Types of Rubber). Insulating material is based on operating temperature. Cores are identified by color coding by using different coolers on insulation or by number printing on cores

Beading:

This portion of the cable is also known as inner sheath. Mostly it is used in Multi core cables. It works as binder for insulated conductors together in multi-core power cables and provides bedding to armor/braid. This portion of the cable is mainly made of PVC( PVC ST-1, PVC ST-2 ), RUBBER (CSP SE-3, CSP SE-4 and PCP SE-3, PCP SE-4, HOFR SE-3 HOFR SE-4, HD HOFR SE-3 ETC)

Armoring:

There are mainly G.I. WIRE ARMOURING, G.I. STEEL STRIP armoring. It is done by placing G.I. WIREs, GI or STEEL STRIPs one by one on inner sheath. Armoring is a process which is done mainly for providing earthling shield to the current carrying conductors as well as it is also used for earthling purpose of the cable for safety. When there is any insulation failure in the conductor, the fault current gets enough paths to flow through the amour if it is properly earthed. Providing extra mechanical protection and strength to cable is an important added advantage of armoring. In MINING CABLES it is done for conductance.

Outer Sheath:

This is outermost cover of the cable normally made of PVC (Poly Vinyl Chloride), RUBBER (Various Types of Rubber) and often the same material as the bedding. It is provided over the amour for overall mechanical, weather, chemical and electrical protection. Outer sheath is protection offered to cable not much electrically but more mechanically.