Magisterial probe finds laxity in transformer maintenance

Insufficient earthing may have sparked Mawphlang electrocution

SHILLONG: The magisterial inquiry conducted into the electrocution of six persons including a 35-year-old pregnant woman and her seven-month-old baby on October 27 at Nongthymmai Neng village in Mawphlang has found that there was slackness in the maintenance of the transformer that resulted in the incident even as the inquiry has called for a more detailed technical probe into the incident.
As per the magisterial inquiry report available with The Shillong Times, it is clear that the maintenance of the transformer was rather lax.

The Rangbah Shnong stated in the inquiry that he had complained about strange sounds emitted by the transformer with requests to check it, but to no avail as there was no response.

The report added that questions may also be raised if the earthing for the transformer is adequate as per Rural Electrification Corporation Construction Standards and whether the earthing is in compliance with the regulations of the Central Electrical Authority (Technical Standards for Construction of Electrical Plants and Electric Lines) Regulations, 2010.

However, the report said that the theory of the MeECL authorities that the power surge started due to a lightning strike may hold water.

Terming it as bizarre that the power surge had to be broken by a man with a stick and that no safety mechanism was in place to cut off the power supply from the source once the entire structure got live and once the neutral wire started transmitting at 11 KV to houses, the inquiry further questioned as to why the power was not automatically cut off at source within seconds.

“The loud bang that was heard by witnesses may have been a lightning strike that could have struck anywhere on the line transmitting power at 11 KV”, the report said.

According to the report the photographic evidence and inspection also show that top shed on the left lightning arrester was shattered that may point to a lightning strike besides the aeroplane-like sound that was heard is probably the sound that is usually made when sparks are formed between a live line and the ground.

“The numerous electric meters which had melted, points to the fact that the neutral line which apparently was transmitting power at 11 KV was transmitting at that voltage for a sufficiently long time to melt hard plastic and more significantly, prove fatal,” the report said.

During the inquiry, a witness, Seibor Shangpliang who was working in the fields around  hundred metres from the house of the unfortunate victims said that he heard a loud sound like a gunshot, followed by a droning sound like that of an aeroplane and then another loud bang.

Shangpliang also said that later, he ran to the transformer while instructing some bystanders not to touch anything. On reaching the transformer, he took a dry stick and hit the wires till they broke off the transformer.

Another eyewitness to the fatal event was Rishad Kharryngki (40) who is married to the victim’s sister. He stays next door to the house of Tirot Singh Khyriem.

Kharryngki said that he was at home at the time of occurrence. He recalled that having heard a loud sound, he went out of his house to investigate and saw fire and smoke coming from his sister-in-law’s house.

He said that when he got closer to the house, he saw that his children and some of their friends were near the house and he pulled them away to safety. At that time, he saw Seibor Shangpliang running and giving instructions to not allow anyone to touch anything. The nearby post and the meter were seen to emit more sparks and bursts and this stopped after a few minutes.

The lineman of MeECL, Marchand Lyngdoh in-charge of the area from Wahlyngkien to Kyrphei, said that, contrary to accusations, the transformer is not defective and that the defective transformer which was used four or five years ago had been replaced.

He further stated that the transformer is functioning satisfactorily except for the centre lightning arrester which is not connected and thereby non-functional. He also clarified that the fuses connected to the phase wires were very much functional despite the fact that they were without the cutouts, stating that they had fuses with 30-40 Ampere wires.

“The bridge/cutouts were only removed because children would play around the transformer and remove the cutouts and interrupting power supply,” report said.

The report further added that on October 27, lightning had struck the left lightning arrester but instead of transmitting the lightning to the earthing pit, the wire connected to the lightning arrester touched the structure and it was transmitted to the channel and the support structure of the transformer causing the earthing wire and the neutral wire to be connected.

“This caused the entire transformer and structure to become live with 11 KV. The neutral wire connected to the lines going to domestic houses along with the three phases started transmitting power at 11KV. This may have caused the electric meters to burn and melt,” report said.

error: Content is protected !!