In A B Cables, there are three insulated cores and one insulated neutral core (optional) laid around a bare or covered messenger wire, which carries the load of the cable. There can be one additional power core for street lighting.
Power and Neutral Cores :
Here, the conductor is composed of H2 or H4 grade Aluminium of Class 2 grade to IS: 8130/84. Popular sizes are 16mm2 to 95mm2. Again, insulation can be either cross linked Polyethylene or Polyethylene.
Messenger Conductor :
These are made of either galvanized Steel or Aluminium alloys.
Core Identification :
Either by number printing or by ridges on insulated cores.
In comparison to bare overhead lines, aerial bunched cable has very high degree of safety and reliability due to the conductors being insulated with the best dielectric medium. This ensures good protection against ground and line faults leading to considerable increase in system efficiency as against bare overhead lines. The problem of free-clearance is also minimized.
Aerial bunched cable system is specially suited in limited space conditions like densely populated areas where laying of underground cables is impossible or extremely expensive.
Key Benefits :
- Tampering with power-line like hooking also gets eliminated resulting in much more efficient utilization of power.
- High degree of safety & reliability.
REC specification no.32/1984 an IS: 14255/1995 deals exclusively with LT aerial bunched cables. Additionally, customers have developed their own specification according to their specific needs.