Indian Electricity Rules
Following are the important Electricity Rules 1956 is related directly or indirectly to safety.
Switches should be connected in the live conductor.
Only gang switch shall be connected in the neutral conductor, No link or switch connect.
While marking the conductors use Code of Practice of wiring.
Energy cannot be transformed, converted, supplied or used until the following criteria not cleared.
A suitable circuit breaker or link switch is connected at the secondary side of the transformer.
Every circuit is protected by using proper cut-out.
To run motor or motor group is controlled by a circuit breaker.
Additional precautions should be taken to ensure that no live parts are exposed.
Rules for high and extra high voltage installations
Approval of Inspector is necessary before erecting any high voltage installations.
The installation must be passed the prescribed testing before energizing.
Conductors shall be enclosed in a metallic covering and protect the equipment from overloading by connecting suitable circuit breakers.
For outdoor type of sub-station a metallic fencing of not less than 1.8 m height shall be erected around the transformer.
Provisions in terms of OH line
Lowest conductor Clearance above ground across street.
- Low and Medium Voltage lines – 5.8 m.
- High voltage Lines – 6.1 m.
Lowest conductor Clearance above ground along a street.
- Low and Medium Voltage lines is 5.5 m.
- High voltage lines – 5.8 m.
Conductor Clearance above ground other than along or across the street.
- Low, Medium and High Voltage lines up to 11 KV if bare is 4.6 m.
- Low, Medium and High up to and including 11 KV, if insulated is 4.0 m.
- High Voltage above 11 KV is 5.2 m.
low and medium voltage Clearance of lines from building,
- Vertical Clearance – 2.5 m.
- Horizontal clearance – 1.2 m.
High and extra high voltage Clearance from building.
- Vertical Clearance High Voltage up to 33KV – 3.7m.
- Extra High Voltage above 33KV – 3.7 m, plus 0.3 m for every 33KV part thereof.
High and extra high voltage Clearance from building Pitched Roof.
- Vertical Clearance up to 11KV – 1.2m.
- Above 11KV up to 33KV – 2.2 m.
- Above 33KV – 2m. Plus 0.3m for every 33KV part thereof.
Maximum interval between supports is not exceed 65 m except by prior approval of inspector.
Indian electricity rules regarding to internal wiring:
The minimum size of conductor used in domestic wiring not be less than 1/1.12 mm in copper or 1/1.40 mm in aluminium wire.
For flexible wires the minimum size for wiring is 14/0.193 mm.
The height for meter board, Main switch board are to be fitted 1.5 meters above the ground level.
Casing will be run at a height of 3.0 meters from ground level.
Light brackets should be fixed at a height of 2 to 2.5 meters above the ground level.
The number of points in a sub circuit is not more than 10.
Maximum load in a single sub circuit is 800W or not more than 1000W.
Indian electricity Rules regarding – Voltage drop concept:
I.E. Rule 48:
The insulation resistance between the wiring of an installation and earth should be leakage current may not be exceed 1/50000 the part or 0.02 percent of the full load current.
Permissible voltage drop in a lighting circuit is 2% of the supply voltage.
In a power industrial circuit Maximum permissible voltage drop should not be more than 5% of the declared voltage.
Insulation resistance of any wiring installation should not be less than 1M Ω.
Earth resistance should not be more than 1M Ω.
Indian electricity Rules regarding to power wiring:
In a power sub circuit the load is normally restricted to 3000 watts and number of outlets is two in each sub circuit.
All equipment used in power wiring should be iron clad construction and for wiring use armoured cable.
The length of flexible conduit used for connections between the terminal boxes of motors and starters not more than 1.25 meter.
Every motor, shall be provided with a switch fuse placed near it.
MCQ Question PDF of Module 8: Basic Wiring Practice
- B.I.S. Symbols used for electrical accessories.
- Types of domestic wiring.
- Test board, Extension board and colour code of cables.
- Special wiring circuits – Tunnel, corridor, godown and hostel wiring.
Download MCQ Questions PDF of Basic Wiring Practice