In the 2013-14 fiscal year, a staggering 39,000 power distribution transformers exploded around the country, mainly due to overloading, incurring losses worth Tk290 crore for the authorities, a study has found.
Because of the transformer explosions, consumers had to suffer elongated power outage in addition to the regular load-shedding and the authorities had to deal with additional system loss and revenue damages. Sometimes, the explosions result in fire incidents in the adjacent areas.
Only in August this year, a total of 4,040 transformers, worth around Tk30 crore, went off, the study said.
The study was conducted by the Power Cell under the government’s Power Division. It included a comparison of power distribution characteristics in Bangladesh, the Philippines and Malaysia.
Power Cell Director Md Amzad Hossain told the Dhaka Tribune: “The damage of transformers portrays a very alarming picture. In the last three years, only three exploded in Malaysia – one because of insulation problem and the others from short circuit.”
At present, around 80,000 or 70-80% transformers installed around the country are overloaded and may explode any time, the study has said.
Apart from the overloading problem, the study said inadequate protective measures, poor workmanship and manufacturing errors had also caused many transformers to go off.
Professionals said the overloading is generally caused by illegal connections which lead to overheating of the transformers and eventually the explosions.
Current usually leaves a transformer through two different lines – the high tension and the low tension. The high tension lines have fuses, better known as cut-outs, that turns the system down in case there is overload. But in Bangladesh, the low tension lines do not have any protective measure of that sort.
The study recommended the authorities concerned to install similar protective mechanisms for the low-tension lines as well.
When asked why the low tension lines do not have cut-outs, an official said the low-tension lines never used to get overloaded before.
Professionals also said all the transformers used for power distribution are made in Bangladesh with imported spare parts. One transformer should ideally operate for 20 years. A 200KVA transformer costs up to Tk5 lakh. It it goes out of order or explodes, it can be repaired for reuse at a cost of about Tk1.2-1.3 lakh.
Sometimes installing low quality imported spare parts have also resulting in malfunctioning of the transformers.
According to the study, 36,776 or 5.45% out of a total of 674,787 transformers under the Rural Electrification Board (REB) went off in FY2013-14.
The rate is 6.5% for the Power Development Board, 6.4% for Dhaka Power Distribution Company, 5.25% for Dhaka Electricity Supply Company and 2.41% for the areas under the West Zone Power Distribution Company.
These five companies under the Power Division have a total of 714,465 transformers around the country, of which 79,196 were overloaded, the study said.
Among the distributors, the REB has the highest 76,277 overloaded transformers.
Asked why the rate of overloading was so high in the rural areas, an official said the REB has little control and monitoring over the transformers and the consumers because of manpower shortage.
The study put forward 15 recommendations which include replacing overloaded transformers, installing proper earthing mechanism and checking meters.
It also suggested that the distribution companeis should introduce standard testing for spare parts and repairing and standardise all utilities.