Guidelines for servicing electrical equipment

Observe the following guidelines when you service electrical equipment:

• Check the area for electrical hazards such as moist floors, nongrounded power extension cords, power surges, 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 currents.
• 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 you use 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 you measure 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.