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Building Electrical Installations - Coggle Diagram
Building Electrical Installations
Points to be Inspected in the electrical installation
Introduction
Electrical wiring is an electrical installation of cabling and associated devices such as switches, distribution boards, sockets, and light fittings in a structure.
Electrical maintenance covers all aspects of testing, monitoring, fixing, and replacing elements of an electrical system.
It is essential to carry out a thorough Inspection of the entire electrical installation at least once in a year.
**Service Connection
Main Switchboard
3.Internal wiring & its insulation
Earth tests & bonding
Switches & fuses
Portable apparatus
Fire Precautions**
Insulation Resistance Measurement Procedure
Line to Earth Test
Line to Line Test
Points to be checked in switches and Fuses
i) Every fuse should be of correct size and indicated on the fuse board.
ii) The main contact jaws of all switches should be cleaned.
iii) All switches, fuses, main switches should be numbers properly to identify the circuits.
iv) The VIR wire connection should be rearranged in the distribution boards.
v) All single pole switches should be connected in the phase line.
This can be checked by a test lamp connected between the earth and switch terminal.
Points to be inspected in Portable Equipment's
i) The insulation resistance of the conductors should be checked by a megger.If the reading is low, the cause must be investigated and rectified.
ii) An effective cable grip should be provided on every portable apparatus & also at the plug end, where flexible cable connections are used.
iii) The effectiveness of the cable grip should be checked periodically.
iv)The internal connections should not get distributed when the cable is pulled , jerked or twisted.
v)Where interlocked switch plugs are provided , check if the interlocking action is effective.
vi)In addition to the usual earth connection derived from the plug socket through the connecting cable, as a further measure of safety.
vii)When making cable connections take care to see that the wire ends are twisted and bend into a neat eyelet, to take in the screw securing it.
vii)Hand Lamps, Porcelain or Bakelite lamp holder should be used as far as possible as brass lamp holders are not so safe.
Action to be taken if an Electrical Equipment Catches Fire
ESSENTIAL REQUIREMENTS OF FIRE
i.Oxygen
ii.Fuel
iii.Heat
Fire
Types
Fire Extinguishers
Soda Acid Type
A container as a solution of bi- carbonate soda and a sealed glass bottle contains concentrated sulphuric acid
Chemical Foam Type
Carbon-tetra- chloride is an insulator.
The sealed cartridge contains CO2 with high pressure.
When striking a piston, Carbon-tetra- chloride liquid will produced.
Carbon-tetra- chloride type
It contains aluminium sulphate and bi- carbonate soda and some chemicals in the compartments.
