Domestic Wiring Unit 4a Domestic Wiring: Service mains, meter board and distribution board. Brief discussion on Cleat, Casing & Capping and conduit (concealed) wiring. Two‐way and three‐way control of a lamp. Elementary discussion on fuse and Miniature Circuit Breaker (MCB’s). Electric shock, precautions against shock –Earthing: Pipe and Plate.
Prof. Sagar B. Halbhavi Department of Electrical & Electronics Engineering p g g
Gogte Institute of Technology, Belgaum
[email protected],
[email protected]
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Actuator lever ‐ used to manually trip and reset the circuit breaker. Also indicates the status of the circuit breaker (On or Off/tripped). Most breakers are designed so they can still trip even if the lever is held or locked in the "on" the on position. position This is sometimes referred to as "free trip" or "positive trip" operation. Actuator mechanism ‐ forces the contacts together or apart. Contacts ‐ Allow current when touching and break the current when moved apart. Terminals Bimetallic strip. Calibration screw ‐ allows the manufacturer to precisely adjust the trip current of the device after assembly. of the device after assembly. Solenoid Arc divider/extinguisher apart.
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Terminals Bimetallic strip. Solenoid contactor Arc divider/extinguisher Solenoid Actuator lever ‐ used to manually trip and reset the circuit breaker. Also indicates circuit breaker. Also indicates the status of the circuit breaker (On or Off/tripped). Most breakers are designed so they can still trip even if the lever is till t i if th l i held or locked in the "on" position. This is sometimes referred to as "free trip" or p "positive trip" operation. 7. Base to fix
Pipe Earthing
Plate Earthing
Wooden batten Wiring 1. It is very cheap 2. Skilled labours are not needed 3. It can be done out door 4. Suitable for temporary wiring system
Demerits 1. It is liable to mechanical damage 2. There is fire risk 3. Woods may be eaten away by ants 4. It is not moisture proof 5. It does not give a elegant appearance It does not give a elegant appearance
Cleat Wiring 1. It is very cheap 2 Skilled labours 2. Skilled labours are not needed are not needed 3. It can be done out door Demerits 1. The conductors are liable to mechanical injury 2. There is fire risk 3. Cleats required periodical mentainance 4 It does not give a very elegant appearance 4. It does not give a very elegant appearance
Wooden Casing & Capping‐ Wiring 1. System is comparatively cheap 2 Wiring can easily done 2. Wiring can easily done 3. Unskilled labourers can do this Demerits 1. It is liable to mechanical damage 2. There is fire risk 3. Woods may be eaten away by ants 4 It is not moisture proof 4. It is not moisture proof 5. If capping is not properly done moisture can damage the insulation of wire 6. It does not give a elegant appearance
Conduit Wiring 1. This system enjoys the advantages of all the other wiring systems 2. Wiring quite costly Wiring quite costly 3. Skilled labours are required 4. Most widely adopted 5. Adds Elegance to appearance Demerits 1. System is costly
Concealed Wiring
