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Electrical Safety-Qualified Person. Energized exposed electrical parts. Exposed parts Live or energized parts De-energized parts. 1a. Energized exposed electrical parts. Exposed parts that are de-energized, but not locked/tagged are considered energized, exposed parts. 1b.
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Energized exposed electrical parts • Exposed parts • Live or energized parts • De-energized parts 1a
Energized exposed electrical parts • Exposed parts that are de-energized, but not locked/tagged are considered energized, exposed parts 1b
Working near exposed parts • Only qualified workers can work on or near exposed electrical parts 2a
Working near exposed parts • Live parts operating at less than 50 volts to ground do not need to be de-energized when: • the worker experiences no increased exposure to electrical burns or explosions due to electrical arcs 2b
Working near exposed parts • Lockout/tagout must be performed by a qualified person • Who is considered a qualified person? 2c
Working near exposed parts • Types of excluded electrical work: • general, transmission, distribution installations • communications installations • vehicle installations • railway installations 2d
Distinguishing exposed live parts from other parts • Qualified persons use voltage testing equipment to identify live and de-energized parts • Testing equipment must be rated for the anticipated voltages to be tested 3a
Nominal voltage of exposed live parts • Nominal voltages are values assigned to circuits to designate its voltage class • 120/240 • 480Y/277 • 600 4a
Nominal voltage of exposed live parts • The actual voltage at which a circuit operates can vary from the nominal within a range that permits satisfactory operation • Multi-meters/volt-ohm meters identify voltage 4b
Clearance distances - Unguarded/energized overhead lines • The required distance between the workers and a conductive object that they could contact 5a
Clearance distances - Unguarded/energized overhead lines • Used when working below unguarded, energized lines 5b
Clearance distances - Unguarded/energized overhead lines Exceptions to required distances: • The worker is wearing insulated equipment 5c
Clearance distances - Unguarded/energized overhead lines Exceptions to required distances: • The energized part is insulated from the worker, and all conductive parts at a different potential 5d
Clearance distances - Unguarded/energized overhead lines Exceptions to required distances: • The worker is insulated from all conductive objects at a different potential than the energized part 5e
Clearance distances -overhead lines and vehicles/equipment • Voltages 50 kv or less, the clearance distance is 10 feet • Voltages greater than 50kv, the clearance is 10 feet plus 4 inches for every 10 kv over 50 kv 6a
Clearance distances -overhead lines and vehicles/equipment • When the vehicle is in transit, and the structure is lowered: • the clearance distance is 4 feet for 50 kv or less; or • 4 feet plus 4 inches for every 10 kv over 50 kv for voltage greater than 50 kv 6b
Clearance distances -overhead lines and vehicles/equipment • Insulating barriers • When installed but not attached to a vehicle, the clearance distance is the designed working dimensions of the barrier • Refer to Table S-5 for aerial lift clearance distances 6c
Clearance distances -overhead lines and vehicles/equipment • Employees must not come into contact with vehicles/equipment under an energized line unless the: • employee is wearing proper PPE • equipment/vehicle is located so that no uninsulated part can provide a conductive path to employees 6d
Clearance distances -overhead lines and vehicles/equipment • Do not stand near grounding locations for intentionally grounded equipment/vehicles when contact with overhead wires is possible • Insulation and barriers 6e
Illumination • Do not enter an area containing exposed energized parts unless the area is illuminated • Do not work near exposed energized parts unless the area is properly illuminated • Do not reach into blind areas 7a
Confined spaces • Barriers, shields, and insulation provide protection from energized parts • Secure doors, hinged panels to prevent exposure to energized parts 8a
Handling conductive materials/equipment • Carefully handle conductive materials or equipment that come in contact with your body • Prevent contact with exposed energized parts 9a
Handling conductive materials/equipment • Carefully handle long, conductive objects in areas containing exposed energized parts • Insulation • Guarding • Materials handling 9b
Nonconductive ladders • Portable ladders must have nonconductive siderails if they could contact exposed energized parts • Metal ladders can conduct electricity and cause arcing and shocks 10a
Hazards of conductive apparel • Conductive jewelry and clothing can cause arcing when exposed to energized parts • Remove or cover conductive jewelry and clothing to eliminate risk of conductivity 11a
Proper handling of cords • Don’t raise or lower equipment by its cord • Don’t unplug the equipment by pulling on its cord • Don’t staple or fasten the cord so as to damage outer jacket 12b
Equipment inspection • Visually check for: • loose parts • deformed or missing parts • damaged jackets or insulation • Inspect for internal defectives, such as pinched or crushed outer jackets 12c
Equipment inspection • Perform inspections prior to beginning each shift • Remove defective equipment from service • Check the plug and receptacle mating configuration before connecting 12d
Flexible cords • Flexible cords with grounding-type of equipment must have an equipment grounding conductor 12e
Flexible cords • Never remove or alter the cord’s grounding pin • Never use an adapter with a missing grounding pin 12f
Types of electrical equipment and cords to be used near water 12g
Proper methods for plugging/unplugging • Ensure hands are dry • Never pull the plug out by the cord 12h
Proper methods for plugging/unplugging • Handle cords and equipment with insulating protective equipment when the cord connector is wet • Secure locking-type connectors after making connection 12i
Circuit breakers and circuits • Never use the following to open and close electrical circuits • Fuses • Terminal lugs • Cable connectors • Cable splice connections 13a
Circuit breakers and circuits • Don’t manually re-energize a circuit without first determining if the equipment and circuit can be safely energized • Don’t modify overcurrent protective devices 13b
Circuit breakers and circuits • Testing of electrical equipment should be performed by qualified persons only • Keep flammables and combustibles away from electrical equipment 13c
Protective equipment • Personal protective equipment includes: • Headgear • Eye and face protection • Rubber insulating gloves • Rubber insulating sleeves • Protective footwear 14a
Protective equipment • Inspect protective equipment to ensure its reliability and safety • Use insulated tools/equipment around exposed energized parts 14b
Protective equipment • Protective shields, barriers, insulating materials protect employees from: • accidental contact • dangerous electrical heating • arcing 14c
Protective equipment • Normally enclosed live parts must be guarded during maintenance 14d
Alerting techniques • Signs and markings • Barricades • Attendants 15a
Summary of key points • Definitions • De-energized means locked/tagged out • Safe distances for clearances between workers and energized lines 16a
Summary of key points • Nonconductive ladders • Nonconductive clothing • Proper use of cords, plugs, receptacles 16b
Summary of key points • Proper use of electrical equipment around flammables/combustibles • Protective equipment • Alerting techniques 16c