Electrical Safety - Indian Standards
In the field of electrical engineering, engineers and other professionals get exposed to electricity indirectly during generation, transportation, installation and usage. Such conditions might cause hazards if accurate safety measures are not taken.
To promote the safety and the right usage of equipment, there are certain rules and regulations formulated by the Bureau of Indian Standards (BIS). BIS follows the following five principles −
- Safety
- Ease of use and adaptability
- Simple technology
- Value for money products
- Energy efficiency and environment
BIS has published the following code of practice for public safety standards in order to promote the right to information, transparency and accountability in a proper manner to the public.
Code of Practice for Electrical Wiring Installation
IS − 732 (1989)
Section − Electrical Installation
Application − Design of installation, selection and erection of equipment, inspection and testing of wiring system
Code of practice for Earthing
IS − 3043 (1987)
Section − Electrical Installation
Application − Design, installation and calculation of Earthing system
Lightning arrester for Alternating Current System
IS − 3070 (1993)
Section − Electro technical: Surge Arresters
Application − Identification, ratings, classification and testing procedure of Arrester
Let us now consider other important codes of practice established by BIS for the purpose of electrification. The codes are listed in the table below −
| General Requirements |
| Sr. No. |
Standards & Application |
| 1 |
IS:900
Installation and maintenance of Induction motors |
| 2 |
IS:1271
Classification of insulating materials for electrical machinery |
| 3 |
IS:1646
Fire safety of buildings (general) electrical installation |
| 4 |
IS:1882
Outdoor installation of Public Address System (PAS) |
| 5 |
IS:1886
Installation and maintenance of Transformers |
| 6 |
IS:1913
General and safety requirements of electric lighting fittings |
| 7 |
IS:2032
Graphical symbols related to electrical technology |
| 8 |
IS:2274
Electrical wiring installations where system voltage is more than 658 volts |
| 9 |
IS:3034
Fire safety of industrial buildings (Electrical generation and distribution stations) |
| 10 |
IS:3072 (part-1)
Installation and maintenance of switchgear where system voltage is less than 1000 volts |
| 11 |
IS:3106
Selection, installation and maintenance of fuse where system voltage is less than 650 volts |
| 12 |
IS:3638
Guide for gas operated relays |
| 13 |
IS:3646
Practice for interior illumination |
| 14 |
IS:3716
Guide for insulation coordination |
| 15 |
IS:3842
Guide for electrical relays for AC system |
| 16 |
IS:4004
Guide for lightening arrestors (non-linear ) for AC system |
| 17 |
IS:4146
Guide for voltage transformers |
| 18 |
IS:4201
Guide for current transformers |
| 19 |
IS:5571
Selection of electrical equipment in hazardous area |
| 20 |
IS:5572
Types of hazardous areas for electrical installations |
| 21 |
IS:5780
Intrinsically safe electrical apparatus and circuit |
| 22 |
IS:5908
Measurement of electrical installations in buildings |
Switchgear
The following table lists down the codes of practice for the maintenance of switchgear −
| General Requirements |
| Sr. No. |
Standards & Application |
| 1 |
IS:375
Making and arrangement for switchgear bus-bars, main connections and auxiliary winding
|
| 2 |
IS:694(part-1)
PVC insulating cables with copper conductors (where voltage is up to 100v) |
| 3 |
IS:1248
Direct acting electrical indicating instruments |
| 4 |
IS:2147
Degrees of protections for enclosures for switchgear and control gear (low voltage) |
| 5 |
IS:2208
Guide for HRC fuse (up to 650v) |
| 6 |
IS:3202
Guide for climate proofing of electrical equipment |
| 7 |
IS:3231
Guide for electrical relays of power system protection |
| 8 |
IS:4047
Guide for heavy duty air break switches and fuses for voltage less than 1000v |
| 9 |
IS:4237
Requirements for switchgears and control gears for voltage up to 1000v |
| 10 |
IS:5987
Selection of switches where voltage is up to 1000v |
| 11 |
IS:335
Insulating oil for transformers and switch gear |
| 12 |
IS:2516(part-1,sec-2)
AC circuit breakers (Tests for the voltage range 1000v to 11000v) |
| 13 |
IS:3427
Metal enclosed switch gear and control gear for voltage within 1000v to 11000v |
| 14 |
IS:722
AC electricity meters for 415 volts |
| 15 |
IS:1951
PVC sleeving for electrical works |
| 16 |
IS:2516(part-1sec-1 & part-2sec2)
AC circuit breaker (Tests for voltage within 1000v) |
| 17 |
IS:2419
Guide for dimension of electrical indicating instruments |
Motor Control Centre (MCC)
The following table lists down the codes of practice for the maintenance of Motor Control Centre −
| General Requirements |
| Sr. No. |
Standards & Application |
| 1 |
IS:1554(part-1)
PVC insulated heavy duty electric cables for the voltage up to 1100v |
| 2 |
IS:1822
AC motor starters of voltage less than 1000v |
| 3 |
IS:2959
AC contactors of voltage less than 1000v |
| 4 |
IS:3961(part-2)
Recommended current ratings for PVC insulated and PVC sheathed cables |
| 5 |
IS:5124
Installation and maintenance of AC induction motor starters within 1000v |
| 6 |
IS:2959
Guide for AC contactors of voltage less than 1000v |
Invertors
The following table lists down the codes of practice for the maintenance of invertors −
| General Requirements |
| Sr. No. |
Standards & Application |
| 1 |
IS:391
Mains transformers for electronic equipment |
Transformers
The following table lists down the codes of practice for the maintenance of transformers −
| General Requirements |
| Sr. No. |
Standards & Application |
| 1 |
IS:335
Insulating oil for transformer and switch gear |
| 2 |
IS:2026
Power transformers |
| 3 |
IS:2099
High voltage porcelain bushings |
| 4 |
IS:3637
Gas operated relays |
| 5 |
IS:3639
Fitting and accessories for power transformers |
Motors
The following table lists down the codes of practice for the maintenance of motors −
| General Requirements |
| Sr. No. |
Standards & Application |
| 1 |
IS:325
3-ph induction motors |
| 2 |
IS:4691
Degrees of protection provided by enclosures for rotating machinery |
| 3 |
IS:4722
Guide for rotating electrical machines |
Batteries
The following table lists down the codes of practice for the maintenance of batteries −
| General Requirements |
| Sr. No. |
Standards & Application |
| 1 |
IS:1652
Guide for stationery cells and batteries, lead-acid type with plante positive plates |
Cables
The following table lists down the codes of practice for the maintenance of cables −
| General Requirements |
| Sr. No. |
Standards & Application |
| 1 |
IS:1753
Aluminum conductors for insulated cables |
| 2 |
IS:3961(part-2)
Guide for current ratings for cable |
| 3 |
IS:3975
Guide for mild steel wires, strips and tapes for armouring cables |
| 4 |
IS:5819
Guide for short circuit ratings of high voltage cables |
| 5 |
IS:5831
Guide for PVC insulation and sheath of electric cables |
Alternators
The following table lists down the codes of practice for the maintenance of alternators −
| General Requirements |
| Sr. No. |
Standards & Application |
| 1 |
IS:7132
Guide for testing synchronous machines |
| 2 |
IS:5422
Guide for turbine type generators |
| 3 |
IS:7306
Methods for determining synchronous machine quantities |
