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Guidelines for servicing electrical equipment

Observe these guidelines when servicing electrical equipment.

  • Check the area for electrical hazards such as moist floors, nongrounded power extension cords, and missing safety grounds.
  • Use only approved tools and test equipment. Some hand tools have handles that are covered with a soft material that does not provide insulation from live electrical current.
  • Regularly inspect and maintain your electrical hand tools for safe operational condition. Do not use worn or broken tools or testers.
  • Do not touch the reflective surface of a dental mirror to a live electrical circuit. The surface is conductive and can cause personal injury or equipment damage if it touches a live electrical circuit.
  • Some rubber floor mats contain small conductive fibers to decrease electrostatic discharge. Do not use this type of mat to protect yourself from electrical shock.
  • Do not work alone under hazardous conditions or near equipment that has hazardous voltages.
  • Locate the emergency power-off (EPO) switch, disconnecting switch, or electrical outlet so that you can turn off the power quickly in the event of an electrical accident.
  • Disconnect all power before you perform a mechanical inspection, work near power supplies, or remove or install main units.
  • Before you work on the equipment, disconnect the power cord. If you cannot disconnect the power cord, have the customer power-off the wall box that supplies power to the equipment and lock the wall box in the off position.
  • Never assume that power has been disconnected from a circuit. Check it to make sure that it has been disconnected.
  • If you have to work on equipment that has exposed electrical circuits, observe the following precautions:
    • Make sure that another person who is familiar with the power-off controls is near you and is available to turn off the power if necessary.
    • When you are working with powered-on electrical equipment, use only one hand. Keep the other hand in your pocket or behind your back to avoid creating a complete circuit that could cause an electrical shock.
    • When using a tester, set the controls correctly and use the approved probe leads and accessories for that tester.
    • Stand on a suitable rubber mat to insulate you from grounds such as metal floor strips and equipment frames.
  • Use extreme care when measuring high voltages.
  • To ensure proper grounding of components such as power supplies, pumps, blowers, fans, and motor generators, do not service these components outside of their normal operating locations.
  • If an electrical accident occurs, use caution, turn off the power, and send another person to get medical aid.