Massive fire at Mumbai high-rise, Jan 22, 2022, 10:22AM IST Source: Times Now




The REAL REASONS behind Fire accidents in Buildings


The reason for accidents in residential buildings are (1) failure of power supply company to provide safe power supply complying the regulations. (2) Safety officers (Electrical inspectorates) failing to ensure implementation of safety regulations by the energy supply company.


Mumbai News 22 January 2022: 6 killed, 23 injured in fire at 20-storey residential building - According to today's Lokmat Newspaper total 26,000 fire cases happened in Mumbai out of which 75% are because of Short Circuit. 26,000 fire cases in just last 5 years means approximately 5,000 cases/year or 400 cases/month or 13 cases/day.



Compromising safety in an electrical installation could be disastrous. Unfortunately, the violations of safety regulations by energy supply company, which are not under the control of electricity consumer are the first reason for accidents.


The electrical safety regulations, code of practices and standards are made based on several research. They are continuously modified to ensure safety based on the changing environment of electricity usage. They are made to ensure that electricity is not a cause of accident (especially ignition off fire).


The only available, reliable and known safety measure during a fault in general condition is to disconnect the supply within a short time before electricity ignites fire. (e.g disconnect the supply to a faulty equipment or wiring within 0.2 seconds to protect from electric shock and 3 seconds to avoid ignition of fire). Influencing factors on safety by automatic disconnection are the power supply incoming, wiring in the building and quality of connected equipment.

Responsibility of Power Supply Company. CEA regulations (ref. electricity act 2003)


Regulation 14, 15 and 16 explains how to supply power to a low voltage consumer. Following these regulations ensure that in case of a fault in a consumer premise the protective device (FUSE/MCB) belonging to the electricity company disconnect the supply quickly before the fault creates an accident.




The supply company shall test and ensure minimum insulation resistance of 5 Mega Ohm at a consumer premise (Regulation 33). The supply company is also supposed to test insulation resistance periodically with in every 5 years (regulation 30).



However, across India the supply companies rarely follow these regulations. Accidents are less in places where these regulations are followed and high in places where the regulations are not followed. As a result, the first culprit of the accidents is the power supply company and the authorities who are supposed to ensure implementation of safety regulations by CEA.


Every electrical apparatus is designed, manufactured, and tested to ensure an accident-free performance throughout its lifetime. ISI marking in a product ensure the compliance to safety requirements of products. However, protection of the wiring and protection due to fault in an apparatus shall be made externally.


The arguments such as fire due to overload, degraded wiring & faulty equipment is baseless. The protective device provided by the power supply company and by the consumer are supposed to disconnect in case of overcurrent and a fault.


Safety Regulation of the Govt of India are made mostly for electricity supply companies to ensure safety at distribution and at consumer premise. They mostly cover the requirements up to point of commencement of supply. The regulation 12(2) ask to follow Code of Practices or the National Electrical Code of India for wiring inside consumer’s premise.



The IS732, called as code of practice for wiring, during 1989 implemented testing of electrical installation at a consumer premise. The testing ensure that the wiring is designed and erected to ensure safety. Mistakes or safety violations can be immediately found out during testing and can be rectified.


Ideally the electricity supply company or the safety officer who is supposed to ensure implementation of safety regulation shall ensure the implementation of regulation 12(2). But these tests are unknown to electrical engineers in India and are rarely/partially carried out.


It’s obvious that accidents can happen in an installation, which does not follow the code of practices. During covid-19 period we saw number of fire accidents in Hospitals especially in medical locations. The National Electrical Code 2011 included additional safety measures to be followed in medical locations, however out of 1000’s of major hospitals across India, the one who follow this code of practice can be counted in fingers.


Similar is the situation with all leading luxury hotels (including the major chain of hotels who run 5 star hotels across several cities).


The accidents can be reduced only if


  1. Power supply company provide safe power supply complying the regulations 14,15,16, 30, 33, 40, 41 & 42.

  • TN-S or TN-C-S system to be made mandatory

  • Ensure that Temporary over voltage of 1200 volts, 5 seconds are not crossed during a fault at HV side of supplier’s transformer.

  • Check insulation resistance every 5 years (regulation 30 & 33)

  • Insist for complete testing as per IS732 in high raise and critical buildings, ensure that all mistakes are rectified.

Note: The above can be implemented without additional cost for the power supply company.


2. Safety officers (Electrical inspectorates) to ensure implementation of above safety

regulations by the energy supply company.

  • Ensure that the power supply company is not violating the above recommendations in Sl. no 1

  • Ensure that high raise and critical buildings, complete tests as per IS732 are carried out and mistakes are rectified.

  • All hospitals with OT or critical care centers are following safety requirements of IS732 and NEC:2011.


By

S. Gopa Kumar

Member

IEC TC64: (Electrical Safety) MT 3, MT 12, MT 40, MT 41, PT 60364-8-3, WG 43

TC81: (Lightning Protection and Safety) ahG 19, MT 3, MT 14, MT 21, WG 18

SC 37 A: (Surge Protection device) WG3 & WG05

BIS NBC (National Building Code of India, Part 8, Section 2 – Electrical installation),

ETD 20 (National Electrical Code, IS732, IS3043)

ETD 30

ETD 50

397 views0 comments