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This guide outlines safety measures and regulations for working with exposed and energized electrical parts, including clearance distances, handling conductive materials, and proper use of portable electrical equipment. Stay safe and prevent accidents with these essential guidelines.
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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