Worried over devastating fires due to short-circuits, senior power expert K K K Nair had proposed to the Prime Minister Narendra Modi and Maharashtra CM a set of rules for using miniature circuit breakers (MCBs) for various electrical gadgets in such a way that they quickly arrest supply of current to ‘short-circuit-hit or overheated wire areas’ and thus do not allow the fires to spread further.
It is an established fact that around 90% fire incidents in Mumbai region are due to short-circuits including Friday’s Virar hospital fire which is also suspected to be out of short-circuit due to overloading of gadgets or ill-maintenance of wires. Thousands of people have lost lives in short-circuit fires in Mumbai in the past 20 years. “CM Thackeray has forwarded my letter to the cooperatives department for further action,” he pointed out.
Nair said electricians, builders and consumers are installing high current (or high ampere) MCBs just because they cost more. But installing disproportionately wrong MCB for any gadget can result in short-circuits getting additional current to escalate the fire further. Nair said while lights, refrigerators and fans should get ‘6 to 10 ampere (A) C’ MCBs, the gadgets like geysers or 1.5 tone ACs need ’16 (A) C’ MCBs each. For a two tonne air-conditioner (AC) the same MCB should be of ’20 (A) C’ value. The main switch in the meter room should be ’32 ampere 4 pole C’ MCB rather than an old fashioned iron-clad switch.
“Also minimum wire size should be ‘1.5milli meter square (mm2)’ throughout. The MCBs with rating 16A, 20A should be wired with 2.5mm2 and 4mm2 wires respectively. All wires should be of 660/1100V grade and made in copper. Their tightening at joints should be firmly packed in order to make networks fire-proof,” Nair added.
Power expert Ashok Pendse said even if fire audit of electrical networks through certified engineers every 5 years and change of wires or switches every 15-20 years are made mandatory as per law, the housing society members will have to proactively take the responsibility of obeying these legal obligations. “Else such a statutory provision will not work given the limited staff for vigilance as against the large population,” he added.