Recent series of fire incidents in Mumbai’s high rises seems to have alerted the authorities to take some proactive steps which, they believe, if implemented may help to increase fire safety in the buildings.
As per the ADSI-2019 report, there were 11,037 fire accidents reported across the country in 2019. The number of such reported fire accidents fell by around 16% compared to 2018. The decline was more steeped compared to the year earlier, which was around 2%. But decline in the number of cases may be due to inaccurate reporting than improvement in the quality of construction.
Fire in buildings due to electrical short circuit is common from the day of invention of electricity. Statistics shows approximately 40 % fires in buildings are due to electrical reason such as short circuit in low voltage system. Result of these accidents are loss of property and human lives and inconvenience to neighbours.
General reasons such as panels are under stair case, electrical panels not in an accessible area, electrical room used for storage, rodents damaging cables, protective devices are bye passed…. etc are the commonly known reasons for fire accidents in the buildings. About 80 % of accidents are due to earth fault.
Electrical installation in industrial and commercial premises are physically inspected & statutory compliances are verified or at least there are provisions which require such verification. So, it’s reasonable to assume that equipment layout, protective device sizing, conductor sizing etc are well taken care with the available knowledge. Periodic inspection of earth resistance, insulation resistance, hotspot measurement, load current measurement are also supposed to be carried out. Despite such provisions accidents do take place in commercial and industrial premises and the reason behind “fire due to electrical short circuit” is unknown.
So, there is no guarantee that if electrical audits of high rise residential buildings are made mandatory (as has been reported in some newspapers) it would save the buildings from future fire hazards.
In fact, standard such as IS 732, IS 3043 explains different ways of achieving safety. Fault loop impedance plays major role in automatic disconnection of power supply. Indian standards recommend measurement of fault loop impedance, but never followed in India due to lack of awareness. Understanding the recommended safety measure -earthed equipotentialisation and automatic disconnection of supply- and implementing in buildings will reduce “fire due to short circuit” to a great extent. Safety measures such as fire / smoke detection, automatic suppression, evacuation, including audit will be of little use if this fundamental electrical safety requirement is not made mandatory in all buildings.