Transcript Electrical Safety: Qualified Person

Electrical SafetyQualified Person
Energized exposed
electrical parts
• Exposed parts
• Live or energized
parts
• De-energized parts
1a
Energized exposed
electrical parts
• Exposed parts
that are deenergized, 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 deenergized 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 Unguarded/energized
overhead lines
• 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 Unguarded/energized
overhead lines
• 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 Unguarded/energized
overhead lines
• 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 Unguarded/energized
overhead lines
• 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 Unguarded/energized
overhead lines
• 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
Procedures for using
portable electrical
equipment
12a
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 groundingtype 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
• Equipment must be approved
for use in these types of
locations.
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