Overheating power strips

Avoid overheating power strips. Check your power strip from time to time to be sure that it is within its warrantied lifetime and that devices are plugged into it correctly.

According to the National Safety Council, electrical failure is the cause of more than 140,000 fires each year, resulting in 400 deaths, 4,000 injuries and $1.6 billion in property damage. In the workplace, electrical hazards cause nearly one fatality every day in the United States.

Multiple-outlet power strips (pictured) can fail. People also sometimes use them improperly. One such instance occurred after a Fermilab employee returned from the holidays. He noticed that the power strip in his office had burn marks near the outlet into which a small power adapter was plugged. He unplugged the power adapter, which tripped the breaker on the power strip as well as the breaker panel on the wall. Members of Fermilab’s Electrical Safety Subcommittee determined that an internal connection had oxidized and had begun slowly heating over time enough to discolor and soften the plastic. The plastic was soft enough to allow two internal conductors to short so that, when the employee unplugged the adapters, the breakers tripped. This incident could have resulted in a building fire, serious injury or even a fatality.

To help avoid this type of incident, the Electrical Safety Subcommittee urges everyone to ensure that:

  • electrical devices plugged into power strips are completely inserted and tight-fitting.
  • the total current of the plugged-in devices adds up to less than the current rating of the strip.
  • two or more power strips are never plugged together (daisy-chained).
  • you unplug your power strip and contact your supervisor if the power strip is hot to the touch or shows signs of discoloration or melting.

The ESH&Q Section urges everyone to replace your power strip if:

  • the light is not illuminated when on (if so equipped).
  • the power strip is beyond its useful life or appears to be an older model.
  • you are aware of signs of suspect/counterfeit items. View a slide show about SC/I training.

Also, consider getting a surge-protected power strip to protect your computer equipment.

If you are unsure about your power strip, surge protector or outlet strip, contact your supervisor, electrical coordinator or senior safety officer. These items can be ordered from the Fermilab Stock Room and have already been approved for usage. Talk to your supervisor also about considering installment of additional outlets where needed, rather than relying on extension cords and power strips. Check all electrical equipment for the UL or other label signifying that it has been tested by a qualified laboratory. Read all manufacturers’ instructions carefully to determine the useful life of the product. Most manufacturers usually recommend a five-year lifespan. Another way to determine the useful life is by the number of years covered under the manufacturer’s warranty.

J.B. Dawson, ESH&Q