Electrical Safety Qualified Person Energized exposed electrical parts

Electrical Safety. Qualified Person

Energized exposed electrical parts v Exposed parts v Live or energized parts v De-energized parts 1 a

Energized exposed electrical parts v Exposed parts that are deenergized, but not locked/tagged are considered energized, exposed parts 1 b

Working near exposed parts v Only qualified workers can work on or near exposed electrical parts 2 a

Working near exposed parts v 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 2 b

Working near exposed parts v Lockout/tagout must be performed by a qualified person v Who is considered a qualified person? 2 c

Working near exposed parts v Types work: of excluded electrical • general, transmission, distribution installations • communications installations • vehicle installations • railway installations 2 d

Distinguishing exposed live parts from other parts v Qualified persons use voltage testing equipment to identify live and de-energized parts v Testing equipment must be rated for the anticipated voltages to be tested 3 a

Nominal voltage of exposed live parts v Nominal voltages are values assigned to circuits to designate its voltage class • 120/240 • 480 Y/277 • 600 4 a

Nominal voltage of exposed live parts v The actual voltage at which a circuit operates can vary from the nominal within a range that permits satisfactory operation v Multi-meters/volt-ohm identify voltage meters 4 b

Clearance distances - Unguarded/energized overhead lines v The required distance between the workers and a conductive object that they could contact 5 a

Clearance distances - Unguarded/energized overhead lines v Used when working below unguarded, energized lines 5 b

Clearance distances - Unguarded/energized overhead lines Exceptions to required distances: v The worker is wearing insulated equipment 5 c

Clearance distances - Unguarded/energized overhead lines Exceptions to required distances: v The energized part is insulated from the worker, and all conductive parts at a different potential 5 d

Clearance distances - Unguarded/energized overhead lines Exceptions to required distances: v The worker is insulated from all conductive objects at a different potential than the energized part 5 e

Clearance distances - overhead lines and vehicles/equipment v Voltages 50 kv or less, the clearance distance is 10 feet v Voltages greater than 50 kv, the clearance is 10 feet plus 4 inches for every 10 kv over 50 kv 6 a

Clearance distances - overhead lines and vehicles/equipment v 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 6 b

Clearance distances - overhead lines and vehicles/equipment v Insulating barriers • When installed but not attached to a vehicle, the clearance distance is the designed working dimensions of the barrier v Refer to Table S-5 for aerial lift clearance distances 6 c

Clearance distances - overhead lines and vehicles/equipment v 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 6 d

Clearance distances - overhead lines and vehicles/equipment v Do not stand near grounding locations for intentionally grounded equipment/vehicles when contact with overhead wires is possible • Insulation and barriers 6 e

Illumination v Do not enter an area containing exposed energized parts unless the area is illuminated v Do not work near exposed energized parts unless the area is properly illuminated v Do not reach into blind areas 7 a

Confined spaces v Barriers, shields, and insulation provide protection from energized parts v Secure doors, hinged panels to prevent exposure to energized parts 8 a

Handling conductive materials/equipment v Carefully handle conductive materials or equipment that come in contact with your body v Prevent contact with exposed energized parts 9 a

Handling conductive materials/equipment v Carefully handle long, conductive objects in areas containing exposed energized parts • Insulation • Guarding • Materials handling 9 b

Nonconductive ladders v Portable ladders must have nonconductive siderails if they could contact exposed energized parts v Metal ladders can conduct electricity and cause arcing and shocks 10 a

Hazards of conductive apparel v Conductive jewelry and clothing can cause arcing when exposed to energized parts v Remove or cover conductive jewelry and clothing to eliminate risk of conductivity 11 a

Procedures for using portable electrical equipment 12 a

Proper handling of cords v Don’t raise or lower equipment by its cord v Don’t unplug the equipment by pulling on its cord v Don’t staple or fasten the cord so as to damage outer jacket 12 b

Equipment inspection v Visually check for: • loose parts • deformed or missing parts • damaged jackets or insulation v Inspect for internal defectives, such as pinched or crushed outer jackets 12 c

Equipment inspection v Perform inspections prior to beginning each shift v Remove defective equipment from service v Check the plug and receptacle mating configuration before connecting 12 d

Flexible cords v Flexible cords with groundingtype of equipment must have an equipment grounding conductor 12 e

Flexible cords v Never remove or alter the cord’s grounding pin v Never use an adapter with a missing grounding pin 12 f

Types of electrical equipment and cords to be used near water 12 g

Proper methods for plugging/unplugging v Ensure hands are dry v Never pull the plug out by the cord 12 h

Proper methods for plugging/unplugging v Handle cords and equipment with insulating protective equipment when the cord connector is wet v Secure locking-type connectors after making connection 12 i

Circuit breakers and circuits v Never use the following to open and close electrical circuits • Fuses • Terminal lugs • Cable connectors • Cable splice connections 13 a

Circuit breakers and circuits v Don’t manually re-energize a circuit without first determining if the equipment and circuit can be safely energized v Don’t modify overcurrent protective devices 13 b

Circuit breakers and circuits v Testing of electrical equipment should be performed by qualified persons only v Keep flammables and combustibles away from electrical equipment 13 c

Protective equipment v Personal includes: protective equipment • Headgear • Eye and face protection • Rubber insulating gloves • Rubber insulating sleeves • Protective footwear 14 a

Protective equipment v Inspect protective equipment to ensure its reliability and safety v Use insulated tools/equipment around exposed energized parts 14 b

Protective equipment v Protective shields, barriers, insulating materials protect employees from: • accidental contact • dangerous electrical heating • arcing 14 c

Protective equipment v Normally enclosed live parts must be guarded during maintenance 14 d

Alerting techniques v Signs and markings v Barricades v Attendants 15 a

Summary of key points v Definitions v De-energized means locked/tagged out v Safe distances for clearances between workers and energized lines 16 a

Summary of key points v Nonconductive ladders v Nonconductive clothing v Proper use of cords, plugs, receptacles 16 b

Summary of key points v Proper use of electrical equipment around flammables/combustibles v Protective v Alerting equipment techniques 16 c