Guidelines for servicing electrical equipmentObserve the following guidelines when you service electrical equipment:v Check the area for electrical hazards such as moist floors, nongrounded powerextension cords, and missing safety grounds.v Use only approved tools and test equipment. Some hand tools have handles thatare covered with a soft material that does not provide insulation from liveelectrical currents.v Regularly inspect and maintain your electrical hand tools for safe operationalcondition. Do not use worn or broken tools or testers.v 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 ifit touches a live electrical circuit.v Some rubber floor mats contain small conductive fibers to decrease electrostaticdischarge. Do not use this type of mat to protect yourself from electrical shock.v Do not work alone under hazardous conditions or near equipment that hashazardous voltages.v Locate the emergency power-off (EPO) switch, disconnecting switch, or electricaloutlet so that you can turn off the power quickly in the event of an electricalaccident.v Disconnect all power before you perform a mechanical inspection, work nearpower supplies, or remove or install main units.v Before you work on the equipment, disconnect the power cord. If you cannotdisconnect the power cord, have the customer power-off the wall box thatsupplies power to the equipment and lock the wall box in the off position.v Never assume that power has been disconnected from a circuit. Check it tomake sure that it has been disconnected.v If you have to work on equipment that has exposed electrical circuits, observethe following precautions:– Make sure that another person who is familiar with the power-off controls isnear you and is available to turn off the power if necessary.– When you are working with powered-on electrical equipment, use only onehand. Keep the other hand in your pocket or behind your back to avoidcreating a complete circuit that could cause an electrical shock.– When you use a tester, set the controls correctly and use the approved probeleads and accessories for that tester.– Stand on a suitable rubber mat to insulate you from grounds such as metalfloor strips and equipment frames.v Use extreme care when you measure high voltages.v To ensure proper grounding of components such as power supplies, pumps,blowers, fans, and motor generators, do not service these components outside oftheir normal operating locations.v If an electrical accident occurs, use caution, turn off the power, and send anotherperson to get medical aid.Safety ix
