Article - September 18, 2017 By LarsonElectronics.com

Avoiding Transformer Fires and Explosions – Best Practices and Safety Guidelines

In 2013, a coal-fired power plant in Georgia was rocked by a crippling explosion that injured three workers. During routine maintenance, a transformer caught on fire, resulting in damages to critical control rooms and other sections of the facility.

Investigators who were tasked with providing evidence surrounding the incident verified that human error was the cause of the accident. Operators failed to communicate properly during operations. The explosion stemmed from a volatile mixture of hydrogen and air.

OSHA released a memo, under Region 4 News Release: 13-1937-ATL (259), highlighting the violations observed by investigators. A total of 17 citations were raised, which amounted to $119,000 in proposed penalties.

Why Do Transformer Fires Happen?

Transformer fires occur when abnormal conditions are present. For electric transformers that rely on oil for cooling, the presence of a high-energy arc (during an internal fault) can set off explosive gases, if left unaddressed. This causes oil to vaporize, causing massive amounts of pressure to build up inside the unit. As pressure accelerates, the transformer becomes overwhelmed, resulting in an explosion.

Lightning strikes can also cause transformers to explode – though such instances are considered to be rare. Moreover, outdated transformers may have faulty protective circuits, which could fail to turn off the unit, should voltage spikes or abnormal conditions occur.

Tips for Avoiding Transformer Fires and Explosions

Below are some tips for preventing transformer fires:

• Use explosion proof equipment

• Perform periodic inspections and testing

• Use a transformer protector and monitoring devices

• Ensure pressure relief valves are working properly

• Install water-spraying systems or foam-extinguishing units

• Educate workers and operators

Note: Some of these techniques are designed to prevent transformer fires from spreading, in the event of an explosion. While other recommendations, such as the use of explosion proof equipment, help reduce the possibility of igniting flammable compounds present in the hazardous location.