Electrical and LOTO
Safety Awareness
Introduction
004-2024
• Injuries associated with
electrical hazards include:
– Heart attack
– Thermal burns
– Falls resulting in injuries
SLIDE-2
Regulations
SLIDE-3
004-2024
• Cal-OSHA regulations are listed under Title 8 of
the California Code of Regulations (CCR)
– General Industry Safety Orders (GISO)
– Construction safety orders
– Electrical safety orders
• Low voltage under 600v
• High voltage over 600v
Regulations
004-2024
• Only qualified persons shall work
on electrical equipment or
systems.
• Only qualified persons shall be
permitted to perform any function
in proximity to energized overhead
conductors unless means to
prevent accidental contact have
been provided.
SLIDE-4
Electric Shock
004-2024
SLIDE-5
• When two wires have different potential differences
(voltages), current will flow if they are connected together
– In most household wiring, the black wires are at 110 volts relative to
ground
– The white wires are at zero volts because they are connected to
ground
• If you come into contact with an energized (live) wire, and you
are also in contact with the grounded wire, current will pass
through your body and YOU WILL RECEIVE A SHOCK
• Contact with both energized wires of a 240-volt cable will
deliver a shock.
– This type of shock can occur because one live wire may be at +120 volts
while the other is at –120 volts during an alternating current cycle, which
is a potential difference of 240 volts.
Shock Severity
004-2024
• Severity of the shock depends on:
– Path of current through the body
– Amount of current flowing through the
body (amps)
– Duration of the shocking current
through the body
• LOW VOLTAGE DOES NOT
MEAN LOW HAZARD
SLIDE-6
Thermal Burns
004-2024
• Thermal burns are the most
common shock-related injury
– Occurs when you touch electrical
wiring or equipment that is
improperly used or maintained
• Typically occurs on hands
• Very serious injury that needs
immediate attention
SLIDE-7
Falls
004-2024
• Electric shock can also cause
indirect injuries
– Workers in elevated locations
who experience a shock may
fall, resulting in serious injury or
death
SLIDE-8
LOTO
004-2024
• Apply locks to power source after
de-energizing
– Tag deactivated controls
– Tag de-energized equipment and
circuits at all points where they can
be energized
– Tags must identify who placed the
tag and when
SLIDE-9
Energized
004-2024
• Work shall not be performed on
exposed energized equipment until :
– Responsible supervision has determined
that the work is to be performed while the
equipment is energized.
– Involved personnel have received
instructions on the work techniques and
hazards involved in working on energized
equipment.
SLIDE-10
Energized
004-2024
• Suitable personal protective equipment and
safeguards (i.e., approved insulated gloves or
insulated tools) are provided and used.
– Rubber insulating gloves shall meet the provisions
of the American Society for Testing Materials
(ASTM) D 120-95
– Insulated tools shall meet the provisions of the
ASTM F 1505-94
• Approved insulated gloves shall be worn for
voltages in excess of 250 volts.
• Suitable eye protection has been provided
and is used.
SLIDE-11
Energized
004-2024
• After the required work on
energized equipment has been
completed, an authorized person
shall be responsible for:
– Removing from the work area any
temporary protective equipment, and
– Reinstalling all permanent barriers or
covers.
• All electrical equipment and
systems shall be treated as
energized until tested or otherwise
proven to be de- energized.
SLIDE-12
Work Space
004-2024
SLIDE-13
• Suitable access and working space shall be provided
and maintained about all electric equipment to permit
ready and safe operation and maintenance of such
equipment.
– The dimension of the working space in the direction of
access to energized parts which require examination,
adjustment, servicing, or maintenance while energized, shall
not be less than:
– 36 inches and
– The minimum headroom shall be 6 feet 3 inches.
Guarding
004-2024
SLIDE-14
• All openings in boxes, enclosures or fittings shall be
effectively guarded against accidental contact by
approved cabinets or closed to afford protection
substantially. This can also be accomplished by:
– By location in a room, vault, or similar enclosure that is
accessible only to qualified persons.
– By suitable permanent, substantial partitions or screens so
arranged that only qualified persons will have access to the
space within reach of the energized parts.
Marking
004-2024
• On all electrical equipment, markings shall be
provided giving:
– Voltage,
– Current,
– Wattage, or other ratings.
• Each disconnecting means for motors and utilization
equipment and for each service, feeder, or branch
circuit at the point where it originates shall be legibly
marked to indicate its purpose unless located and
arranged so the purpose is evident.
• The markings shall be of sufficient durability to
withstand the environment involved.
SLIDE-15
Accidents
004-2024
• Electrical accidents are
caused by a combination of
three factors:
– Unsafe equipment and/or
installation
– Workplace made unsafe by the
environment
– Unsafe work practices
SLIDE-16
Accidents
004-2024
• Use guards or
barriers
• Replace covers
• Fix damaged wires
• Conductors going
into boxes must be
protected, and
unused openings
must be closed
SLIDE-17
Inadequate Wiring
004-2024
SLIDE-18
• Hazard - wire too small for the current
• Example - portable tool with an extension
cord that has a wire too small for the tool
– The tool will draw more current than the cord can
handle, causing overheating and a possible fire
without tripping the circuit breaker
– The circuit breaker could be the right size for the
circuit but not for the smaller-wire extension cord
Wire Gauge
WIRE
Overhead Powerlines
SLIDE-19
004-2024
• Overhead power lines are usually not
insulated
• Examples of equipment that can
contact power lines:
–
–
–
–
–
–
–
Crane
Ladder
Scaffold
Backhoe
Scissors lift
Raised dump truck bed
Aluminum paint roller
Overhead Powerlines
004-2024
• If there is a chance of
contact recommend placing
warning signs
– Stay at least 10 feet away
• Assume that lines are energized
• Use wood or fiberglass ladders,
not metal
• Power line workers need
special training & PPE
SLIDE-20
Cords
004-2024
• Cords can be damaged by:
– Aging
– Door or window edges
– Staples or fastenings
– Abrasion from adjacent materials
– Activity in the area
• Improper use can cause shocks, burns
or fire
– Remove cords by pulling on the plugs, not the
cords
SLIDE-21
Flexible Cords
004-2024
SLIDE-22
• Flexible cords shall be used only in continuous lengths without
splice or tap.
– Hard service flexible cords No. 12 or larger shall be permitted to be
repaired if spliced so that the splice retains the insulation, outer sheath
properties, and usage characteristics of the cord being spliced.
• Flexible cords shall be repaired or replaced if the outer sheath
is damaged such that any conductor insulation or conductor is
exposed.
– Repair of the outer sheath shall only be permitted if the conductors are
not damaged and the completed repair retains the insulation, outer
sheath properties, and usage characteristics of the cord being repaired.
• Flexible cords shall be connected to devices and fittings so that
strain relief is provided which will prevent pull from being
directly transmitted to joints or terminal screws.
Cord Inspection
004-2024
• Deformed or missing pins
• Damaged outer jacket or
insulation
• Evidence of internal
damage
• If damaged, take out of
service until repaired
SLIDE-23
Grounding
004-2024
• Tools plugged into improperly grounded
circuits may become energized
– Check wiring with a tester
• Make sure that the plug does not have a
broken ground
• Do not convert a grounded plug to an
ungrounded plug
SLIDE-24
GFCI
004-2024
• Ground Fault Circuit Interrupter
(GFCI or GFI) protects you from
shock
– Detects difference in current
between the black and white wires
– If ground fault detected, GFCI shuts
off electricity in 1/40th of a second
SLIDE-25
Overloaded Circuits
004-2024
• Too many devices plugged into a circuit
can:
– Heat up wires and possibly start a fire
– Damage tools due to overheating
– Melt the wire insulation, which may cause
arcing and a fire in the area where the
overload exists, even inside a wall
– Do not daisy chain multi outlet strips
SLIDE-26
Protective Devices
004-2024
• A circuit breaker or fuse
automatically opens the circuit
if excess current from overload
or ground-fault is detected –
shutting off electricity
– They are for protection of property
not people
– If activated fuses have to be
replaced and circuit breakers have
to be reset
SLIDE-27
Power Tools
004-2024
• Inspect power tools and extension cord before using
them
• Use a GFCI
• Store in dry place when not using
• Don’t use in wet/damp conditions
• Don’t carry a tool by the cord
• Don’t yank the cord to disconnect it
• Keep cords away from heat, oil, & sharp edges
• Disconnect when not in use and when changing
accessories such as blades & bits
• Remove damaged tools from use
SLIDE-28
Electrical Hazard Clues
004-2024
• Tripped circuit breakers or blown
fuses
• Warm tools, wires, cords,
connections, or junction boxes
• GFCI that shuts off a circuit
• Worn or frayed insulation around
wire or connection
SLIDE-29
Work Practices
004-2024
• Use non prime hand to throw switch
– Stand to side of panel when throwing switch
– Turn head away from panel right before throwing
switch
• Remove jewelry
• Use barriers and guards to prevent passage
through areas of exposed energized
equipment
– Pre-plan work, post hazard warnings and use
protective measures
– Keep working spaces and walkways clear of cords
SLIDE-30
Training
004-2024
• Train employees on the
following:
– Deenergize electric equipment
before inspecting or repairing
– Using cords, cables, and electric
tools that are in good repair
– Lockout / Tagout recognition and
procedures
– Use of appropriate personal
protective equipment
SLIDE-31
Training
004-2024
SLIDE-32
• Qualified workers
– How to identify exposed energized parts
– How to safeguard or work on energized parts
• Unqualified workers
– How electricity works
– Risks of working with energized equipment
– Tasks to be performed only by qualified workers
SOP
004-2024
SLIDE-33
• When a circuit is abandoned or discontinued, its
conductors shall be removed from the raceways, or be
maintained as if in use.
• In locations where electric equipment would be
exposed to physical damage, enclosures or guards
shall be so arranged and of such strength as to
prevent such damage.
• No grounded or grounding conductor shall be
attached to any terminal or lead so as to reverse
designated polarity.
PPE
004-2024
• Where insulating rubber gloves
are used for shock protection,
leather protectors shall be worn
over the rubber gloves.
• Heavy-duty leather work shoes
provide some arc flash
protection to the feet and shall
be used in all exposures greater
than 4 cal/cm2 .
SLIDE-34
PPE
004-2024
SLIDE-35
• Proper PPE can include Flame Resistant clothing, hardhat,
hood, face shield, safety glasses, gloves, shoes, etc. depending
upon the magnitude of the arc energy.
• Employees working in areas where electrical hazards are
present shall be provided with, and shall use, PPE that is
designed and constructed for the specific part of the body to be
protected and for the work to be performed.
• PPE are intended to protect a person from arc flash and shock
hazards.
– While some situations could result in burns to the skin, even with the
protection selected, burn injury should be reduced and survivable.
– Due to the explosive effect of some arc events, physical trauma injuries
could occur.
Insulated Tools
004-2024
• Employees shall use insulated tools or
handling equipment, or both, when
working inside the limited approach
boundary of exposed energized electrical
conductors where tools or handling
equipment might make accidental contact.
– Insulated tools shall be protected from damage
to the insulating material.
• Insulated tools shall be rated for the
voltages on which they are used.
• Insulated tools shall be designed and
constructed for the environment to which
they are exposed and the manner in
which they are used.
SLIDE-36
Job Briefing
004-2024
SLIDE-37
• Before starting each job, the employee in charge shall conduct
a job briefing with the employees involved.
• The briefing shall cover such subjects as hazards associated
with the job, work procedures involved, special precautions,
energy source controls, PPE requirements, and the information
on the energized electrical work permit, if required.
• Additional job briefings shall be held if changes that might affect
the safety of employees occur during the course of the work.
Testing
004-2024
SLIDE-38
• Only qualified persons shall perform tasks such as testing,
troubleshooting, and voltage measuring within the limited
approach boundary of energized electrical conductors operating
at 50 volts or more or where an electrical hazard exists.
– Test instruments and equipment and all associated test leads, cables,
power cords, probes, and connectors shall be visually inspected for
external defects and damage before each use.
– If there is a defect or evidence of damage that might expose an
employee to injury, the defective or damaged item shall be removed from
service, and no employee shall use it until repairs and tests necessary to
render the equipment safe have been made.
– When test instruments are used for testing the absence of voltage on
conductors or circuit parts operating at 50 volts or more, the operation of
the test instrument shall be verified before and after an absence of
voltage test is performed.
Stored Energy
004-2024
SLIDE-39
• The procedure shall include requirements for releasing stored
electric or mechanical energy that might endanger personnel.
• All capacitors shall be discharged, and high capacitance
elements shall also be short-circuited and grounded before the
associated equipment is touched or worked on.
• Springs shall be released or physical restraint shall be applied
when necessary to immobilize mechanical equipment and
pneumatic and hydraulic pressure reservoirs.
• Other sources of stored energy shall be blocked or otherwise
relieved.
Auditing
004-2024
SLIDE-40
• The electrical safety program shall be audited to verify the
principles and procedures of the electrical safety program are in
compliance with this standard.
– The frequency of the audit shall not exceed 3 years.
• Field work shall be audited to verify the requirements contained
in the procedures of the electrical safety program are being
followed. When the auditing determines that the procedures of
the electrical safety program are not being followed, the
appropriate revisions to the training program or revisions to the
procedures shall be made.
• The audit shall be documented.
004-2024
Questions?
SLIDE-41