Electrical Safety- Qualified Person. Energized exposed electrical parts Exposed partsExposed parts...
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Transcript of Electrical Safety- Qualified Person. Energized exposed electrical parts Exposed partsExposed parts...
Energized exposed Energized exposed electrical partselectrical parts• Exposed partsExposed parts
• Live or energized Live or energized partsparts
• De-energized partsDe-energized parts
1a
Energized exposed Energized exposed electrical partselectrical parts• Exposed parts Exposed parts
that are de-that are de-energized, but energized, but not locked/tagged not locked/tagged are considered are considered energized, energized, exposed partsexposed parts
1b
Working near exposed Working near exposed partsparts• Only qualified workers can Only qualified workers can
work on or near exposed work on or near exposed electrical partselectrical parts
2a
Working near exposed Working near exposed partsparts• Live parts operating at less than Live parts operating at less than
50 volts to ground do not need to 50 volts to ground do not need to be de-energized when:be de-energized when:• the worker experiences no increased the worker experiences no increased
exposure to electrical burns or exposure to electrical burns or explosions due to electrical arcsexplosions due to electrical arcs
2b
Working near exposed Working near exposed partsparts• Lockout/tagout Lockout/tagout
must be must be performed by a performed by a qualified personqualified person
• Who is Who is considered a considered a qualified person?qualified person?
2c
Working near exposed Working near exposed partsparts• Types of excluded electrical work:Types of excluded electrical work:
• general, transmission, distribution general, transmission, distribution installationsinstallations
• communications installationscommunications installations• vehicle installationsvehicle installations• railway installationsrailway installations
2d
Distinguishing exposed live Distinguishing exposed live parts from other partsparts from other parts• Qualified persons Qualified persons
use voltage testing use voltage testing equipment to equipment to identify live and de-identify live and de-energized partsenergized parts
• Testing equipment Testing equipment must be rated for must be rated for the anticipated the anticipated voltages to be testedvoltages to be tested
3a
Nominal voltage of exposed Nominal voltage of exposed live partslive parts• Nominal voltages are values Nominal voltages are values
assigned to circuits to designate assigned to circuits to designate its voltage classits voltage class• 120/240120/240• 480Y/277480Y/277• 600600
4a
Nominal voltage of exposed Nominal voltage of exposed live partslive parts• The actual voltage at which a The actual voltage at which a
circuit operates can vary from the circuit operates can vary from the nominal within a range that nominal within a range that permits satisfactory operationpermits satisfactory operation
• Multi-meters/volt-ohm meters Multi-meters/volt-ohm meters identify voltageidentify voltage
4b
Clearance distances - Clearance distances - Unguarded/energized Unguarded/energized overhead linesoverhead lines• The required distance The required distance
between the workers and a between the workers and a conductive object that they could conductive object that they could contactcontact
5a
Clearance distances - Clearance distances - Unguarded/energized Unguarded/energized overhead linesoverhead lines• Used when working below Used when working below
unguarded, energized linesunguarded, energized lines
5b
Clearance distances - Clearance distances - Unguarded/energized Unguarded/energized overhead linesoverhead linesExceptions to required distances:Exceptions to required distances:• The worker is wearing insulated The worker is wearing insulated
equipmentequipment
5c
Exceptions to required distances:Exceptions to required distances:• The energized part is insulated from the The energized part is insulated from the
worker, and all conductive parts at a worker, and all conductive parts at a different potentialdifferent potential
5d
Clearance distances - Clearance distances - Unguarded/energized Unguarded/energized overhead linesoverhead lines
Exceptions to required distances:Exceptions to required distances:• The worker is insulated from all The worker is insulated from all
conductive objects at a different conductive objects at a different potential than the energized partpotential than the energized part
5e
Clearance distances - Clearance distances - Unguarded/energized Unguarded/energized overhead linesoverhead lines
• Voltages 50 kv or less, the Voltages 50 kv or less, the clearance distance is 10 feetclearance distance is 10 feet
• Voltages greater than 50kv, the Voltages greater than 50kv, the clearance is 10 feet plus 4 inches clearance is 10 feet plus 4 inches for every 10 kv over 50 kvfor every 10 kv over 50 kv
6a
Clearance distances - Clearance distances - Unguarded/energized Unguarded/energized overhead linesoverhead lines
• When the vehicle is in transit, and When the vehicle is in transit, and the structure is lowered:the structure is lowered:• the clearance distance is 4 feet for 50 the clearance distance is 4 feet for 50
kv or less; orkv or less; or• 4 feet plus 4 inches for every 10 kv 4 feet plus 4 inches for every 10 kv
over 50 kv for voltage greater than over 50 kv for voltage greater than 50 kv50 kv
6b
Clearance distances - Clearance distances - Unguarded/energized Unguarded/energized overhead linesoverhead lines
• Insulating barriersInsulating barriers• When installed but not attached to a When installed but not attached to a
vehicle, the clearance distance is the vehicle, the clearance distance is the designed working dimensions of the designed working dimensions of the barrierbarrier
• Refer to Table S-5 for aerial lift Refer to Table S-5 for aerial lift clearance distancesclearance distances
6c
Clearance distances - Clearance distances - Unguarded/energized Unguarded/energized overhead linesoverhead lines
Clearance distances - Clearance distances - Unguarded/energized Unguarded/energized overhead linesoverhead lines
• employee is wearing proper employee is wearing proper PPEPPE
• equipment/vehicle is located equipment/vehicle is located so that no uninsulated part so that no uninsulated part can provide a conductive can provide a conductive path to employeespath to employees
6d
• Employees must not come into contactEmployees must not come into contact
with vehicles/equipment under an with vehicles/equipment under an
energized line unless the:energized line unless the:
• Do not stand near grounding Do not stand near grounding locations for intentionally locations for intentionally grounded equipment/vehicles grounded equipment/vehicles when contact with overhead wires when contact with overhead wires is possibleis possible• Insulation and barriersInsulation and barriers
6e
Clearance distances - Clearance distances - Unguarded/energized Unguarded/energized overhead linesoverhead lines
IlluminationIllumination• Do not enter an area Do not enter an area
containing exposed containing exposed energized parts unless the energized parts unless the area is illuminatedarea is illuminated
• Do not work near exposed Do not work near exposed energized parts unless the energized parts unless the
area is properly area is properly illuminatedilluminated
• Do not reach into blind Do not reach into blind areasareas
7a
Confined spacesConfined spaces• Barriers, shields, and insulation Barriers, shields, and insulation
provide protection from energized provide protection from energized partsparts
• Secure doors, hinged panels to Secure doors, hinged panels to prevent exposure to energized prevent exposure to energized partsparts
8a
Handling conductive Handling conductive materials/equipmentmaterials/equipment• Carefully handle conductive Carefully handle conductive
materials or equipment that come materials or equipment that come in contact with your bodyin contact with your body
• Prevent contact with exposed Prevent contact with exposed energized partsenergized parts
9a
Handling conductive Handling conductive materials/equipmentmaterials/equipment• Carefully handle long, conductive Carefully handle long, conductive
objects in areas containing objects in areas containing exposed energized partsexposed energized parts• InsulationInsulation• GuardingGuarding• Materials handlingMaterials handling
9b
Nonconductive laddersNonconductive ladders• Portable ladders must have Portable ladders must have
nonconductive siderails if they nonconductive siderails if they could contact exposed could contact exposed energized partsenergized parts
• Metal ladders can Metal ladders can conduct electricity conduct electricity and cause arcing and cause arcing and shocksand shocks
10a
Hazards of conductive Hazards of conductive apparelapparel• Conductive jewelry Conductive jewelry
and clothing can and clothing can cause arcing when cause arcing when exposed to energized exposed to energized partsparts
• Remove or cover Remove or cover conductive jewelry conductive jewelry and clothing to and clothing to eliminate risk of eliminate risk of conductivityconductivity
11a
Procedures for using Procedures for using portable electrical portable electrical equipmentequipment
12a
Proper handling of cordsProper handling of cords
• Don’t raise or lower Don’t raise or lower equipment by its cordequipment by its cord
• Don’t unplug the Don’t unplug the equipment by pulling equipment by pulling on its cordon its cord
• Don’t staple or fasten Don’t staple or fasten the cord so as to the cord so as to damage outer jacketdamage outer jacket
12b
Equipment inspectionEquipment inspection• Visually check for:Visually check for:
• loose partsloose parts• deformed or missing deformed or missing
partsparts• damaged jackets or damaged jackets or
insulationinsulation
• Inspect for internal Inspect for internal defectives, such as defectives, such as pinched or crushed pinched or crushed outer jacketsouter jackets
12c
Equipment inspectionEquipment inspection• Perform inspections Perform inspections
prior to beginning prior to beginning each shifteach shift
• Remove defective Remove defective equipment from equipment from serviceservice
• Check the plug and Check the plug and receptacle mating receptacle mating configuration before configuration before connectingconnecting
12d
Flexible cordsFlexible cords• Flexible cords with grounding-Flexible cords with grounding-
type of equipment must have type of equipment must have an equipment grounding an equipment grounding conductorconductor
12e
Flexible cordsFlexible cords
• Never remove or Never remove or alter the cord’s alter the cord’s grounding pingrounding pin
• Never use an Never use an adapter with a adapter with a missing grounding missing grounding pinpin
12f
Types of electrical Types of electrical equipment and cords to equipment and cords to be used near waterbe used near water
12g
• Equipment must be approved Equipment must be approved
for use in these types of for use in these types of
locations.locations.
Proper methods for Proper methods for plugging/unpluggingplugging/unplugging
• Ensure hands Ensure hands are dryare dry
• Never pull the Never pull the plug out by the plug out by the cordcord
12h
Proper methods for Proper methods for plugging/unpluggingplugging/unplugging• Handle cords and equipment with Handle cords and equipment with
insulating protective equipment insulating protective equipment when the cord connector is wetwhen the cord connector is wet
• Secure locking-type connectors Secure locking-type connectors after making connectionafter making connection
12i
Circuit breakers and Circuit breakers and circuitscircuits• Never use the following to open Never use the following to open
and close electrical circuitsand close electrical circuits• FusesFuses• Terminal lugsTerminal lugs• Cable connectorsCable connectors• Cable splice connectionsCable splice connections
13a
Circuit breakers and Circuit breakers and circuitscircuits• Don’t manually re-Don’t manually re-
energize a circuit energize a circuit without first without first determining if the determining if the equipment and equipment and circuit can be circuit can be safely energizedsafely energized
• Don’t modify Don’t modify overcurrent overcurrent protective devicesprotective devices
13b
Circuit breakers and Circuit breakers and circuitscircuits• Testing of electrical Testing of electrical
equipment should be equipment should be performed by performed by qualified persons qualified persons onlyonly
• Keep flammables Keep flammables and combustibles and combustibles away from electrical away from electrical
equipmentequipment
13c
Protective equipmentProtective equipment• Personal protective Personal protective
equipment includes:equipment includes:• HeadgearHeadgear• Eye and face Eye and face
protectionprotection• Rubber insulating Rubber insulating
glovesgloves• Rubber insulating Rubber insulating
sleevessleeves• Protective footwearProtective footwear
14a
Protective equipmentProtective equipment• Inspect protective Inspect protective
equipment to equipment to ensure its ensure its reliability and reliability and safetysafety
• Use insulated Use insulated tools/equipment tools/equipment around exposed around exposed energized partsenergized parts
14b
Protective equipmentProtective equipment• Protective shields, barriers, Protective shields, barriers,
insulating materials protect insulating materials protect employees from:employees from:• accidental contactaccidental contact• dangerous electrical dangerous electrical
heatingheating• arcingarcing
14c
Protective equipmentProtective equipment
• Normally Normally enclosed live enclosed live parts must be parts must be guarded during guarded during maintenancemaintenance
14d
Alerting techniquesAlerting techniques
• Signs and markingsSigns and markings
• BarricadesBarricades
• AttendantsAttendants
15a
Summary of key pointsSummary of key points
• DefinitionsDefinitions
• De-energized means De-energized means locked/tagged outlocked/tagged out
• Safe distances for clearances Safe distances for clearances between workers and energized between workers and energized lineslines
16a
Summary of key pointsSummary of key points
• Nonconductive laddersNonconductive ladders
• Nonconductive clothingNonconductive clothing
• Proper use of cords, plugs, Proper use of cords, plugs, receptaclesreceptacles
16b