In mines, robust mining cables are utilized to endure adverse conditions such as roof falls, moisture, and other possible sources of damage.
FREMONT, CA: Electricity is used for a variety of functions throughout any mine, both below and above ground. The necessary electrical power is generated from the colliery's generating station or, more commonly, the local electricity supply using a substation.
It is common knowledge that underground cables in collieries must survive adverse conditions such as roof falls, moisture, and other possible sources of damage.
As a result, mining cables must be built to endure the challenges of the job. Additionally, they must be maintained regularly to guarantee their safety and dependability. In fact, for effective coal production, dependable and durable cables are critical.
These mining cables must comply with the earthing requirements, which stipulate that the earthing conductor's conductivity must be at least 50 percent that of one of the power conductors.
PVC or XLP insulated cables with metric dimensions are now utilized in mines for the major high and medium voltage distribution lines. Before the implementation of metric cable sizes, similar cables were used in inch sizes. The inch or imperial size wires are still common today. Before introducing PVC insulated cables, the most popular form of cable was the paper-insulated lead sheathed type.
This type of cable is still used in large quantities. There are cables with two to four cores or conductors available. Three core cables are typically used for three phases, a.c. Distribution, one core for every stage of the supply system.
Installation of Cables:
At the mine's surface, a variety of installation methods are being used. But the manner of installation is determined by the conditions in a specific colliery.
The methods generally are:
Hanging from a centenary wire or hooks on the wall. This is commonly done with rawhides or lead braided cable suspenders.
A duct is constructed by digging a trench and lining it with bricks or concrete, with brackets or cleats fastening the cable to the duct's wall.
The cable trench should be deep enough to accommodate the cable's operating voltage and the site circumstances. The cable must be put in a sand bed on the trench's bottom and then coated with sand. The sand should then be bedded with interlocking cable tiles to give a consistent cover over the length of the buried cable.
The standard way of anchoring a cable vertically in the shaft is to clamp it with wooden cleats at regular intervals. Wooden cleats come in lengths ranging from 2 to 6 feet. The type of cleat chosen is determined by the load that has to be carried.