An instance of fire in a housing society

© 2020 Ramaswami Ashok Kumar,1/13,Telec Officers’ CHSL, Plot-30 Sector-17,Vashi,NaviMumbai-400703.
A member made the following occurrence report
A-Comments(D3)  Background: In the recent past, there were two partial interruptions to power supply where supply to Yellow phase was lost. The first one was due to problem at MSEDCL Kiosk in Plot no 31, whilesecond wasdue to problemin metering panel of building-2 of our society. 1. Investigation revealed there was heavy sparking across Yellow phase in the Main Incomer Switch(fusedisconnectorunit). 2. The Middle phase fusefound to haveshattered into pieces. 3. The disconnector copper strip melted. 4. Insulating materialpasculin partiallyburnt. 5. Entire assembly was found to have burnt/damaged and collapsed within the switch body. 6. There were heavy voltage fluctuations for a period of about one minute till the arc extinguished itself. I was one of the members affected and experienced the fluctuations and entireoccurrence. 7. The sparking/firewas restrictedwithintherobust EE switchand did not spread. 8. Such heavy voltage fluctuations are dangerous to Fridge, TV and electronic & electronicallycontrolled equipment. 9. The damaged switch in Building No 2 was replaced next day. The Switch in Building No 1 also was replaced. 10.There were incidences in the past of overheating of porcelain type fuses, burning of conductors at fuse ends resulting in lossof supplyto some of the flats. 11.There was a peculiar incidence in Flat 2/12 where Fridge, A/C unit, Microwave and Telephone burnt/damaged simultaneously in rainy season. The cause of occurrence could not be established.However, it could be due to high voltage (220 to 440 V). 12.Sparking was observed by Mr. M a , tenant of Flat no 2/04 outside his kitchen at electrical grounding rod.

I will confine myself to the part where it is said that . 3. The disconnector copper strip melted.

The properties of the disconnector copper strip are:

Physical properties

Atomic mass: 63.546

Density: 8.96 g/cm3

Group: Transition metals

Electrons: [Ar] 3d10 4s1

Melting point: 1356.6 K

Boiling point: 2840 K

Discovered: Ancient times

Ref: https://www.gigapromo.in/Compare-Now/Copper Melting Furnace

The World Dam Dynamics could have triggered the occurrence. This I conclude applying the precautionary principle. For 30^th January 2020 starting from 17h UTC to 1759 UTC, World Dam Dynamics is inferred to play out as shown in the Figure below:

In view of these occurrences and the danger of fire inherent in these due to World Dam Dynamics, we should be really considering ourselves fortunate that we have engineers who are all sharing experiences and seeing that the Capital Expenditure Projects come through successfully.
R. Ashok Kumar