Power distribution companies and municipalities are to check the safety of electricity transformer substations in residential buildings after an explosion in an apartment block in Bourgas caused substantial damage.
The blast initially was thought to have been the result of an electrical facility in the basement exploding but EVN said in an October 17 2012 statement that an examination had established that the transformer had not exploded. The company provided a photograph of the intact transformer.
Bulgarian-language media, citing information from power distribution companies EVN, CEZ and Energopro, said that there were 2411 transformer substations in residential buildings inBulgaria.
EVN, supplier to the building that was hit by the blast on October 16, has said that it was bringing in Austrian experts to examine the cause of the explotsion.
One possible scenario being examined is that the oil in the transformer was at too low a level.
Reports after the explosion said that residents had called emergency services after apparent malfunctions of the transformer. After an EVN maintenance crew had responded to call about electricity supply problems, the transformer is said to have emitted dense smoke. The early-morning explosion followed.
Some residents had minor injuries while most escaped harm because they had already left the building.
Bourgas mayor Dimitar Nikolov said that EVN should pay compensation for the extensive damage while a statement by the company said that it would bear costs if its responsibility was established after an expert investigation.
The manufacturer of the transformer, a Pernik company, said in response to Bulgarian media inquiries that the blast was a “very strange incident” unprecedented in the company’s history. The Pernik firm said that it was absolutely impossible for their products to explode. The company said that it had produced 15 000 transformers and such an explosion had never happened. Overheating would result in fire but not an explosion, the company said.
An EVN statement on October 16 said that a visual inspection of the transformer showed it to be largely intact and with no signs of an oil leak.
The incident has caused substantial coverage in the Bulgarian media about whether it is safe to have electricity substations in the basements of residential buildings. At least some date from the days when the state was the power supplier, while others are said to have been installed as a cost-saving option or because in the centre of cities, there was nowhere else to put them.
Bulgarian law allows the installation of transformer substations in residential buildings but this requires the consent of all residents of the building and certification that the facility meets fire, technical and all safety standards.
Regional Development and Public Works Minister Liliana Pavlova said that the suggestion of Bourgas mayor Nikolov, the question would be examined whether installing electricity substations in residential buildings should be banned.
Separately, reports said that children from the building that had been hit by the blast were being treated by psychiatrists for mental trauma.