Page 99 - Electrician - TT (Volume 1)

ELECTRICIAN - CITS

Metallic coupler 3 way junction box Steel Bends

Concealed wiring: In this system small channels are formed in the walls and ceilings etc. When the building is in
under construction. The conduits are erected in these channels by using nails. Wires are drawn through the pipe
after plastering work. Inspection boxes are provided to permit periodical inspection and facilitate removal of wires.
All outlets such as switches and wall socket either of flush mounting or surface mounting type. Metal conduit
pipe should not used as a earth continuity conductor. For earth continuity , separate earth continuity conductor is
drawn through the conduit .

Application
1 Industrial work shop
2 Public buildings
3 Domestic wiring

Advantages and disadvantages of consealed wiring
Advantage Disadvantage
No risk of fire and good protection against Very expensive system of wiring.
mechanical injury.
The lead and return wire can be carried in Requires good skilled workmanship.
the same tube.
Earthing and continuity is assured.

Water proof and trouble shooting is easy. Erection is quiet complicated and time consuming.
Shock proof with proper earthing and bonding. Risk of short circuit under wet conditions (due
to consideration of water in tube)

Durable and maintenance free.
Aesthetic in appearance.
Cleat wiring

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CITS : Power - Electrician & Wireman - Lesson 20-25