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Electrical Safety-Qualified Person

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Title: Electrical Safety: Qualified Person Last modified by: Mary Flanagan Created Date: 3/22/1999 4:19:01 PM Document presentation format: Letter Paper (8.5x11 in) – PowerPoint PPT presentation

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Title: Electrical Safety-Qualified Person


1
Electrical Safety-Qualified Person
2
Energized exposed electrical parts
  • Exposed parts
  • Live or energized parts
  • De-energized parts

1a
3
Energized exposed electrical parts
  • Exposed parts that are de-energized, but not
    locked/tagged are considered energized, exposed
    parts

1b
4
Working near exposed parts
  • Only qualified workers can work on or near
    exposed electrical parts

2a
5
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
6
Working near exposed parts
  • Lockout/tagout must be performed by a qualified
    person
  • Who is considered a qualified person?

2c
7
Working near exposed parts
  • Types of excluded electrical work
  • general, transmission, distribution installations
  • communications installations
  • vehicle installations
  • railway installations

2d
8
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
9
Nominal voltage of exposed live parts
  • Nominal voltages are values assigned to circuits
    to designate its voltage class
  • 120/240
  • 480Y/277
  • 600

4a
10
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
11
Clearance distances - Unguarded/energized
overhead lines
  • The required distance between the workers and
    a conductive object that they could contact

5a
12
Clearance distances - Unguarded/energized
overhead lines
  • Used when working below unguarded, energized
    lines

5b
13
Clearance distances - Unguarded/energized
overhead lines
  • Exceptions to required distances
  • The worker is wearing insulated equipment

5c
14
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
15
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
16
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
17
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
18
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
19
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
20
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
21
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
22
Confined spaces
  • Barriers, shields, and insulation provide
    protection from energized parts
  • Secure doors, hinged panels to prevent exposure
    to energized parts

8a
23
Handling conductive materials/equipment
  • Carefully handle conductive materials or
    equipment that come in contact with your body
  • Prevent contact with exposed energized parts

9a
24
Handling conductive materials/equipment
  • Carefully handle long, conductive objects in
    areas containing exposed energized parts
  • Insulation
  • Guarding
  • Materials handling

9b
25
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
26
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
27
Procedures for using portable electrical equipment
12a
28
Proper handling of cords
  • Dont raise or lower equipment by its cord
  • Dont unplug the equipment by pulling on its cord
  • Dont staple or fasten the cord so as to damage
    outer jacket

12b
29
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
30
Equipment inspection
  • Perform inspections prior to beginning each shift
  • Remove defective equipment from service
  • Check the plug and receptacle mating
    configuration before connecting

12d
31
Flexible cords
  • Flexible cords with grounding-type of equipment
    must have an equipment grounding conductor

12e
32
Flexible cords
  • Never remove or alter the cords grounding pin
  • Never use an adapter with a missing grounding pin

12f
33
Types of electrical equipment and cords to be
used near water
12g
34
Proper methods for plugging/unplugging
  • Ensure hands are dry
  • Never pull the plug out by the cord

12h
35
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
36
Circuit breakers and circuits
  • Never use the following to open and close
    electrical circuits
  • Fuses
  • Terminal lugs
  • Cable connectors
  • Cable splice connections

13a
37
Circuit breakers and circuits
  • Dont manually re-energize a circuit without
    first determining if the equipment and circuit
    can be safely energized
  • Dont modify overcurrent protective devices

13b
38
Circuit breakers and circuits
  • Testing of electrical equipment should be
    performed by qualified persons only
  • Keep flammables and combustibles away from
    electrical equipment

13c
39
Protective equipment
  • Personal protective equipment includes
  • Headgear
  • Eye and face protection
  • Rubber insulating gloves
  • Rubber insulating sleeves
  • Protective footwear

14a
40
Protective equipment
  • Inspect protective equipment to ensure its
    reliability and safety
  • Use insulated tools/equipment around exposed
    energized parts

14b
41
Protective equipment
  • Protective shields, barriers, insulating
    materials protect employees from
  • accidental contact
  • dangerous electrical heating
  • arcing

14c
42
Protective equipment
  • Normally enclosed live parts must be guarded
    during maintenance

14d
43
Alerting techniques
  • Signs and markings
  • Barricades
  • Attendants

15a
44
Summary of key points
  • Definitions
  • De-energized means locked/tagged out
  • Safe distances for clearances between workers and
    energized lines

16a
45
Summary of key points
  • Nonconductive ladders
  • Nonconductive clothing
  • Proper use of cords, plugs, receptacles

16b
46
Summary of key points
  • Proper use of electrical equipment around
    flammables/combustibles
  • Protective equipment
  • Alerting techniques

16c
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