Mahidol electrical engineers offer tips on preventing transformer fires
After a blaze sparked by a faulty transformer torched six shophouses in Bangkok’s Sampheng market last week, Mahidol University’s electrical engineering department has come up with guidelines to prevent a repeat.
The blaze last Sunday, which killed two and injured 11, took firefighters more than two hours to control. The fire also damaged four cars and three motorcycles.
Supun Tiptipakorn, chief of Mahidol University’s Department of Electrical Engineering, explained that transformers are important as they distribute power. He added that most transformers installed outside buildings use oil to prevent short circuits and reduce the temperature.
These oil-type transformers are cheap and their efficiency will drop over time, especially during the hot months when the demand for electricity surges, he said. This can trigger the risk of fire due to voltage overload.
“More than 10,000 of these oil-type transformers were installed in Greater Bangkok and 154 are in inner Bangkok,” he said.
Hence, he said, related agencies should use the following guidelines to prevent transformers from causing damage to people’s lives and properties:
• Use dry-type transformers as they are safer though more expensive.
• Cover areas near transformers with fireproof sheets to prevent fires and do not use transformers with a capacity of more than 250kVA to prevent an explosion.
• Use transformers for no more than 20 years, even those with a lifetime guarantee of 25 years.
• Change oil inside transformers periodically to prevent short circuits and reduce heat.
• Develop a system in which all transformers are checked regularly and people are informed in advance if there is a risk of fire.
• Use only 80 per cent of transformers’ capacity to ensure safety. For instance, only 400kVA should be used from a 500kVA transformer.
• Set up partitions or put up signs stopping people from setting up stalls or parking near transformers. The Metropolitan Electricity Authority (MEA)'s telephone number should be clearly displayed on each transformer so people can contact the authority in case of emergency.
• Keep cables away from transformers as they will trigger a fire.
• Start burying cables and electrical systems, especially in business areas and communities in the heart of the city.
As for people living near transformers, his advice is as follows:
• Close doors and windows near transformers and set up fireproof materials.
• Have a working fire-extinguishing system.
• Monitor the transformer and inform MEA in case of abnormality.
• Avoid activities or parking vehicles near transformers.
• Hold fire drills and evacuation training sessions regularly to boost awareness and reduce loss.
• Get a fire-insurance policy.