When to Replace Aging Transformers: Guidelines to Replace Older Transformers Before Failure

摘要

Transformers play critical roles in delivering power to distribution equipment for homes, commercial establishments, and industrial facilities. The sudden failure of a transformer can cause serious repercussions, leading to loss of power for a few minutes to hours. There are cases where an outage can last for weeks because of the system configuration, such as a simple radial system or the transformer was the single-point failure. In industrial complexes, an outage lasting for a few minutes could lead to loss opportunities as well as millions of dollars in lost production and start-up costs. Many older transformers have been in operation for more than 80 years without failure or major problems. There have been recent failures of units producing fires and explosions, resulting in the release of toxic and combustible gases as well as smoke into the atmosphere; Also, the Occupational Safety and Health Administration (OSHA) has levied fines because of the type of incidents. Many transformers in the petrochemical industry now fall under OSHA 1910.119 [15], mechanical integrity regulations, due to the probability of catastrophic failure during power loss, resulting in the release of highly hazardous chemicals. Transformer tanks containing more than 10,000 lb of aggregates sometime fall under the 1910.119 as well as 1910.269 regulations. Mineral oil in transformers is used as a media for cooling and insulating parts within close proximity. Mineral oil has a National Fire Protection Association (NFPA) flammability rating of one, indicating it is slightly flammable with a health rating of one, indicating a slight health hazard. During fault conditions, however, mineral oil can be hazardous to your health and the environment.