Extension Cord/Power Strip

Extension cords and power strips have the potential to cause fires, electrical shock, loss of power to equipment, and facility damage.

Extension Cords

Use of extension cords at University of Michigan (U-M) is restricted to only providing temporary power for portable equipment (e.g., maintenance, cleaning, audio-visual, or construction activities).  If an extension cord is used, U-M policy states the extension cord must be:

  • Certified by a nationally recognized laboratory (UL, CSA, ITSNA)
  • Used only in continuous lengths without splice or tape

Before using an extension cord:

  • Inspect it and remove it from service if it is damaged
  • Verify it is suitable for the use and location of the equipment

Restrictions to Extension Cord Use

Extension cords cannot be:

  • Connected in series to another cord or power strip (daisy-chain, piggy-back)
  • Continually connected to an outlet for more than 1 work day
  • Used with equipment drawing more than 15 amp
  • Used as a substitute for fixed wiring of a structure
  • Attached to building surfaces
  • Concealed by walls, floors, or ceilings or located above suspended or dropped ceilings
  • Installed in raceways, except when permitted by Code
  • Run through:
    • Holes in walls, ceilings, or floors
    • Doorways, windows, or similar openings
  • Placed where it is subject to physical damage

Power Strips and Surge Suppressors

While a surge suppressor is a power strip, not all power strips are equipped with surge suppression.

  • Power strip: A block of electrical sockets that allows multiple electrical devices to be powered from a single electrical socket.
  • Surge suppressor: An appliance/device designed to protect electrical devices from voltage spikes.

Using Power Strips or Surge Suppressors

When using power strips or surge suppressors, only:

  • One power strip or surge suppressor is allowed per duplex electrical outlet
  • Low current devices such as radios, computers, printers, etc. are allowed to be plugged into it

NOTE: Scientific equipment must be plugged directly into the primary wall outlet.  If sensitive lab equipment requires a surge suppressor, it must be noted in the labs standard operating procedures.

Restrictions on Power Strip or Surge Suppressor Use

Power strips or surge suppressors cannot be used:

  • In a series (daisy-chain, piggy-back)
  • With equipment containing a heating element

For More Information

  • Technical Support: EHS at (734) 647-1143
  • Adding New Outlets: Facilities Maintenance at (734) 647-2059
  • Electrical Hazards
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