Wireman Trade (ALP)

Wireman trade focuses on wiring installation: conduits, switchboards, distribution.

Wiring systems:

• Cleat wiring: wires on porcelain cleats. Outdated; used for temporary.
• Casing-capping: wires in wooden/PVC casing. Cheap; used for households.
• Conduit wiring: wires inside metal/PVC tubes.
  • Surface conduit: visible.
  • Concealed conduit: in walls.
• Tray wiring: cables on metal trays. Industrial.
• Busbar: thick conductors. Industrial.

Wires and Cables:

• Single-strand: thin, flexible.
• Multi-strand: flexible.
• Armoured: protected, underground.
• Sizes: 1.5 mm² (lighting), 2.5 mm² (sockets), 4 mm² (geyser), 6 mm² (AC), 10 mm² (sub-main).

Distribution Board (DB):

• Main switch + MCBs / fuses + bus bars + earthing.
• Single-phase vs three-phase DBs.

Switches and Sockets:

• 5A: lights, fans, sockets.
• 15A: geyser, AC, refrigerator.
• 20A, 32A: large appliances.

Domestic Wiring:

• Main supply → meter → main switch → DB → branch circuits.
• Each circuit: phase + neutral + earth.
• Color code: R-Y-B (3-phase); Phase + N + E (single phase).

Industrial Wiring:

• Higher capacity, more circuits.
• More safety: MCCBs, RCCBs, contactors.
• Star-delta starters for motors.

Conduit installations:

• Bending: cold bending up to 1" pipe.
• Threading: for joins.
• Boxes: junction box at every bend / fixture.

Earthing:

• Every electrical installation must have earthing.
• Earth pit: filled with charcoal + salt.
• Test: earth tester.

Safety:

• Test with multimeter / neon tester before work.
• Switch off main; lock-out tag-out.
• Don't mix phase and neutral.

Tools:

• Wire stripper, crimping tool, conduit cutter, pipe bender, screwdrivers (slotted, Phillips), pliers, multimeter, neon tester.

RRB ALP focus: wiring types, wire sizes, distribution board, safety practices.