6a_ELECTRIC SAFETY.ppt

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CONTENT
1. Factories and machinery (Building operations and works
of engineering construction) (Safety) Regulations
2. Occupational Safety and Health Act (OSHA) 1994
3. Hazards associated with electricity
4. Hazards at workplace
5. Electrical work practice
6. Lock out & tag out
7. General electrical safety requirement
8. Personal protective equipment (PPE)
9. Emergency response for electrocution

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OBJECTIVE
1. To understand the hazard associated with electrical work
2. To understand the safe work procedure

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Background
• Properly used, electricity is the most versatile form of
energy. We use it almost all the time of our waking day,
without any adverse effects.
• However, if potentially hazardous conditions exist and
are ignored, it may result in serious accidents.
• Failure to establish safety in the design, work practices,
procedures, servicing, and maintenance operations for
electrical equipment often result in bodily harm or
even fatalities, property damage, or both.

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Definition
Before we start, an understanding of
electricity and basic electrical terms are
needed.

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Definition
• Current : Think of current as total volume of water flowing past a
certain point in a given length of time. Current is the flow of electric
charge per unit time (1 coulomb per second), measured in Amps.
• Current flow : Current always flows from a point of high voltage to a
point of low voltage, or to the “ground / earth”.
• Direct current : constant flow of electric charge from high to low
potential (Volts) and substantially free from pulsation, sometimes
called continuous current.
• An alternating current : the magnitude and direction of the
current varies cyclically, as opposed to direct current, where the
direction of the current stays constant. The usual waveform of
an AC power circuit is a sine wave, as this results in the most
efficient transmission of energy.

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Definition
• Frequency : is the rate of change of phase of a sinusoidal waveform, in
cycles per second or Hertz.
• Circuit : is an interconnection of electrical elements such as resistors,
inductors, capacitors, diodes, switches and transistors in a closed loop,
i.e. with a return path.
• Fuse : is an overcurrent protection device. Its critical component is a
metal wire or strip that will melt when heated by a prescribed current
.
• Volt : A volt is defined as the potential difference across a conductor
when a current of one ampere dissipates one watt of power.
Voltage = electrical potential difference. Voltage is “additive”.
Voltage less than 60 V is normally considered as low.

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Definition
• Resistance : Electrical resistance is a measure of the degree to which an object
opposes the passage of an electric current. R = V / I. It is
measured in ohms.
• Watt : is a unit of electrical Power. Watt = V x I = I2
R
The unit amount of power consumed = kW-hr
• Grounding : is the wire that carries currents away under fault conditions. This
wire is directly or indirectly connected to one or more earth electrodes which
may be located locally or far away in the suppliers network, or in many cases
both. This grounding wire is usually but not always connected to the neutral
wire .
• Switches : A switch is a device for changing the course (or flow) of a circuit,
or for activating / isolating a circuit.
• Switches, fuses, circuit breakers, ground-fault circuit interrupters, are control
equipment needed to run electrical machinery safely and efficiently.

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Definition
• A three phase system : The generation of AC electric power is commonly three
phase (3 coils in the generator), in which the waveforms of three supply conductors
are offset from one another by 120°.
• A single phase system : The voltage across a pair of conductors in a 3-phase
system, or between a single conductor and a neutral conductor is called single
phase electric power.
• Static electricity : An electrostatic discharge (ESD) is an electric current driven
by an excess electric charge stored on an electrically insulated object.
Discharge creates sparks. Static electricity is generated by friction between
dissimilar substances. Protection is in the form of bonding, earthing, the use of
conducting wrist straps and foot-straps, or anti-static mats to conduct harmful
electric charges away from the work area, and humidity control, because in
humid conditions the surface layer of moisture on most objects conducts
electric charges harmlessly to earth.

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THREE-PHASE SYSTEM
Today, transmission-level
voltages are usually considered
to be 110 kV and above. Lower
voltages such as 66 kV and 33
kV are sub-transmission
voltages but are occasionally
used on long lines with light
loads. Voltages less than 33 kV
are usually used for
distribution.
Voltages above 230 kV (380,
735, 1200 KV) are considered
extra high voltage and require
different designs.

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ELECTRICAL SAFETY
FACTORIES AND MACHINERY BUILDING
OPERATIONS AND WORKS OF ENGINEERING
CONSTRUCTION (SAFETY) REGULATION 1986 (1)
16(1) Before work is begun, the employee shall
ascertain by inquiry or direct observation, or by
instruments, where any part of an electric power circuit,
exposed or concealed, is so located that the
performance of the work may bring any person, tool or
machine into physical or electrical contact with it.

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• 16(2) The employer shall post and maintain proper warning signs in
the national language where such a circuit exists.
• 16(3) The employer shall advice his employees of the location of such
lines, the hazards involved and the protective measures to be taken
and shall if practicable, de-energize the electric power circuit.
ELECTRICAL SAFETY

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ELECTRICAL SAFETY
OPERATIONS AND WORKS OF ENGINEERING CONSTRUCTION
(SAFETY) REGULATION 1986 (3)
16(4) No employer shall suffer or permit an employee
to work in such proximity to any part of an electric
power circuit which exposes him to contact with the
same in the course of his work unless the employee
is protected against electric shock by de-energizing
the circuit and earthing it or by guarding it by
effective insulation or other means acceptable to the
Chief Electrical Inspector.

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ELECTRICAL SAFETY
16(5) In work areas where exact location of underground
electric power lines is unknown, employees using jack-
hammers, bars or other hand tools which may come into
contact with such lines shall be provided with insulated
protective gloves and insulated protective footwear.

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ELECTRICAL SAFETY
OPERATIONS AND WORKS OF ENGINEERING CONSTRUCTION
(SAFETY) REGULATION 1986 (5)
• 16(6) All wiring shall be supported on proper insulators and not looped
over nails or brackets.
• 16(7) No wiring shall be left on the ground or the floor of a building
unless is unavoidable and where it is necessary to lay electric wiring on
the ground or the floor of a building, the wiring shall be of the
weatherproof types and shall be provided with adequate mechanical
protection to maintained in good and safe working order.

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ELECTRICAL SAFETY
• 16(8) No bares wires or other unprotected conductors shall be
located within 4 metres of any surface where employee may
work or pass, unless completely guarded by a fence or other
barrier.

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ELECTRICAL SAFETY
• 16(9) Where electrical appliances and current-carrying equipment have
provisions made for earthing, they shall be properly earthed.
• 16(10) All temporary electrical installations in building and engineering
construction worksites shall be provided with earth leakage circuit
breakers (ELCB).
• 16(11) Elevated power lines shall have a sufficient vertical clearance where
they cross highways, access roads or areas traveled by trucks, cranes,
shovels or other similar equipments and shall not be lower than 5.2 metres
from the ground surface.

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ELECTRICAL SAFETY
• 16(12) All electrical installations in building and engineering
constructions worksites shall comply with the requirements of
the appropriate authority.
• 16(13) All electrical installations shall be tested and approved
by the Chief Electrical Inspector or his representative, before
they are commissioned and such installations shall be
maintained in good and safe working order at all times.

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Employee’s roles
 Considerations:
1. Get involved.
2. Contribute to make corrective actions.
3. Know the hazards associated with your job.
4. Report all accidents and near-misses immediately.
5. Always provide complete and accurate information.
6. Report all electrical safety problems or deficiencies.
7. Follow-up with any additional information.
ELECTRICAL SAFETY

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Supervisor’s Roles
 Considerations:
1. Get involved.
2. Get your workers involved.
3. Never ridicule any injury or near miss.
4. Treat all “Near-misses” as an accident.
5. Complete the paperwork for improvements.
6. Attend the same training as your workers.
7. Get involved in the safeguarding of electrical
sources.
8. Follow-up on the actions you took.
ELECTRICAL SAFETY

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ELECTRICAL SAFETY
• Electricity is an unseen hazard
– Invisible
– Odorless
– Silent

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Electrical Injuries
• Current flow and time are factors
that affect the severity of
electrical injuries. The severity of
electrical shock is determined by
:
 The amount of current which
flows through the victim
 The length of time that the body
receives the current.
The main resistance to current is
the skin surface. Callous, dry skin
has a fairly high resistance –
500,000 Ώ
500 Ώ
500 Ώ
500 Ώ
500 Ώ
100 Ώ

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Effect of Current on Human Body
Min current for RCCB
30 mA
Let-Go still possible
Increased cramp : Limit of Let-Go
Release impossible;
Severe cramp up to thoracic region
7.5
10 – 15
15 – 20
25 – 30
First sensation noticeable
Tickling sensation on hand
Hand feels numb
Similar sensation on wrist
First signs of cramp in hand
Slight cramp in upper arm; ELCB : 5 mA
0.9 – 1.2
1.2 – 1.6
1.6 – 2.2
2.2 – 2.8
2.8 – 5.0
5.0 – 7.0
Effect on Human Body
Current (mA)
SAFETY
ZONE
Limit of Let-Go for a 70 kg person : AC – 15 mA; DC – 75 mA

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ELECTRICAL SAFETY
• Electricity can flow through a conductor
– Example: metal, iron, water, human body
• Certain substances which do not conduct electricity are
called insulator
– Example: wood, plastic, glass, rubber
Remember: It’s the current that kills!

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ELECTRICAL SAFETY
HAZARDS ASSOCIATED WITH ELECTRICITY
• Electric shock
– Direct contact with conductor energized at 50Vac or
above will cause injury
– Indirect contact with exposed conductive part which
become energized under fault condition. At normal
condition it is safe. Example touching electric kettle if the
kettle is faulty
• 3 factors involved in an electric shock:
– Resistance
– Voltage
– Current

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• The lower body resistance, the greater the potential
electric shock hazard
• The higher voltage, the greater the potential electric
shock hazard
• Voltage above 30V is considered dangerous.
• The higher current, the greater the potential electric
shock hazard
• Current flow above 5mA is considered dangerous.
• Current 10mA can produce shock of sufficient
intensity to prevent voluntary control of muscles.
ELECTRICAL SAFETY

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ELECTRICAL SAFETY
The longer time of
exposure,
the greater the
potential electric shock
hazard.
Electric shock current
that passes through
the heart
is very dangerous

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ELECTRICAL SAFETY
HAZARDS ASSOCIATED WITH ELECTRICITY (1)
• Burns
– Contact will hot conductors
– The passage of a current
through the body at the
point of entry and exit
– Electric arcing (sparks)

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Internal Injuries.
 Low voltage (110 – 220 V) through the chest for a fraction of a second may
induce ventricular fibrillation at currents as low as 60mA. Contraction of chest
muscles also cause temporary paralysis of the respiratory mechanism, which may
result in failure to breathe. Blood circulation will cease, as evidenced by lack of
pulse, blood pressure and respiration, and death will occur. The ventricular
muscle twitches randomly, rather than contracting in unison, and so the
ventricles fail to pump blood into the arteries and into systemic circulation.
Above 200mA, muscle contractions are so strong that the heart muscles
cannot move at all. With DC, 300 to 500 mA is required.
• Higher voltages (> 500 V) causes hemorrhages and destruction of tissues,
nerves, and muscles, caused by heat generated by the current flowing along
the electrical circuit’s path through the body
 Severe burns may also result from arcing when metal or jewelry come close
with current-carrying conductors.

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ELECTRICAL SAFETY
(2)
• Fire
– Electricity is a common source of ignition for
major fires
– Source of electrical ignition include
• Sparks – between conductors
• Arcs – a larger discharge of energy
• Short – circuits
• Overloading
• Old and defective/damage wiring

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ELECTRICAL SAFETY
HAZARDS ASSOCIATED WITH
ELECTRICITY (3)
• Explosion
– Caused by electrical short-
circuit or sparking from the
electrical contacts
• Example faulty
transformer

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ELECTRICAL SAFETY
HAZARDS ASSOCIATED WITH ELECTRICITY (4)
• Static electricity exists in industry such as manufacture of man-
made textile, nylon, or where flow of powder in a pipeline
– Static electricity can be source of danger if sparking takes
place in flammable atmospheres, resulting in explosions and
fire e.g non-conductive floor mat

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Electrostatic Discharge
An electrostatic discharge (ESD) is an electric current driven by an excess
electric charge stored on an electrically insulated object. Discharge creates
sparks.
Static electricity is generated when two dissimilar materials come in contact,
e.g. by rubbing, and the electric charge is trapped within one of the materials.
The charge can be concentrated within the conductor, or be grounded and
thus lose its charge, or can “jump” to another object outside the insulated
object which is at a lower voltage.
Characteristics : Very high voltage, very low current. If the static electricity
charge is high enough, it can become a dangerous source of ignition in
combustible surroundings.
Protection : Protection is in the form of bonding between the objects,
earthing, the use of conducting wrist straps and foot straps, or anti-static
mats to conduct harmful electric charges away from the work area, and
humidity control, because in humid conditions the surface area of moisture
on most objects conducts electric charges harmlessly to earth.

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ELECTRICAL SAFETY
HAZARDS IN THE WORKPLACE
(1)
• Overhead power lines
• Digging and trenching operations in
areas where there are underground
power cables
• Damaged, cut or broken insulation
on electrical cables, extension
cords, etc.
• Damaged or broken switches on
power boards
• Damaged or broken housings on
power tools

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ELECTRICAL SAFETY
HAZARDS IN THE WORKPLACE (2)
• Access to high voltage power sources not restricted
• The inappropriate use of extension cords
– Example:use extension cords for permanent fixture
• Bare conductors e.g., bus bars inside high voltage enclosures
• Overloading circuits
– Example: power outlets with too many connections and or
appliances

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FUSES : 1 Amp  200 W
600 W
1,000 W
2,600 W

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ELECTRICAL SAFETY
HAZARDS IN THE WORKPLACE (3)
• Substandard electrical work
– Incorrect installation
– Incorrectly wired circuits
– Equipment, machines, etc. not grounded
– Switches placed on the wire e.g. The on off switch on
the neutral wire instead of the active, etc

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Safe Work Policy
 General
Work on electrical equipment should be done de-
energized (zero volts) unless not possible due to a
compelling reason.
Safety-related work practices must be employed to
prevent electric shock or other injuries resulting from
either direct or indirect electrical contacts, when
work is performed near or on equipment or circuits
which are or may be energized.
ELECTRICAL SAFETY

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De-energized parts
 Live parts must be de-energized before work is
permitted on or near them, unless it can be
demonstrated that de-energizing introduces additional
or increased hazards or is infeasible due to equipment
design or operational limitations.
 Live parts that operate at less than 50 volts to ground
need not to be de-energized if there will be no
increased exposure to electrical burns or to explosion
due to electric arcs.
ELECTRICAL SAFETY

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Energized parts
 If the exposed live parts are not de-energized (I.e. for
reasons of increased or additional hazards or infeasibility),
other safety-related work practices must be used to protect
employees who may be exposed to the electrical hazards
involved.
 Such work practices must protect employees against contact
with energized circuit parts directly with any part of their
body or indirectly through some other conductive object
ELECTRICAL SAFETY

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Working on or near exposed energized parts
 Only qualified persons may work on electric circuit
parts or equipment that have been de-energized.
 Such persons must be capable of working safely on
energized circuits and must be familiar with the proper
use of special precautionary techniques, personal
protective equipment, insulating and shielding
materials and insulated tools.
ELECTRICAL SAFETY

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Dangers of Electrical Shock
• Currents above 10 mA* can
paralyze or “freeze” muscles.
• Currents more than 75 mA can
cause a rapid, ineffective heartbeat
-- death will occur in a few minutes
unless a defibrillator is used
• 75 mA is not much current – a small
power drill uses 30 times as much Defibrillator in use

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Burns
• 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

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Falls
• Electric shock can also
cause indirect injuries
• Workers in elevated
locations who experience
a shock may fall, resulting
in serious injury or death

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Electrical Hazards and How to
Control Them
Electrical accidents are
caused by a
combination of three
factors:
– Unsafe equipment
and/or installation,
– Workplaces made unsafe
by the environment, and
– Unsafe work practices.

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Hazard – Exposed Electrical Parts
Cover removed from wiring or breaker box

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Control – Isolate Electrical Parts
• Use guards or
barriers
• Replace covers
Guard live parts of electric
equipment operating at 50
volts or more against
accidental contact

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Control – Isolate Electrical Parts - Cabinets,
Boxes & Fittings
Conductors going into them must be protected, and
unused openings must be closed

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Hazard - Overhead Power Lines
• Usually not insulated
• Examples of equipment that
can contact power lines:
– Crane
– Ladder
– Scaffold
– Backhoe
– Scissors lift
– Raised dump truck bed
– Aluminum paint roller

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Control - Overhead Power Lines
• Stay at least 10 feet away
• Post warning signs
• Assume that lines are
energized
• Use wood or fiberglass
ladders, not metal
• Power line workers need
special training & PPE

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Overhead lines
 If work is performed near overhead lines, they must be
de-energized and grounded, or other protective
measures provided before work is started.
 If the lines are to be de-energized, arrangements must be
made with the person or organization that operates or
controls them to de-energize and ground them.
 All protective measures, must prevent employees from
contacting lines directly with any body part or indirectly
through conductive materials, tools or equipment.
ELECTRICAL SAFETY

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UNSAFE
SYSTEM OF
WORK :
What do you
think of this
activity?

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ELECTRICAL WORK PRACTICE (1)
• Only trained and qualified (competent) persons are
permitted to carry out installation, service, repair and
maintenance
– Wireman i.e. registered at JBEG/ST/Suruhanjaya
Tenaga Malaysi
– Chargeman i.e. registered at JBEG
– Electrical engineer i.e. register at JBEG / BEM
• Ordinary workers work with electricity must be supervised
by qualified personnel
ELECTRICAL SAFETY

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ELECTRICAL WORK PRACTICE (2)
• Safety related work practices shall be used when work is
performed near or on energized (having current flow
through) electrical equipment:
– Obtain permit to work
– Use insulated tools
– Use the correct and proper method
– Know where the emergency push button
– Avoid wearing jewelry, rings, metallic belt, watches, etc
– Report any fault equipment or abnormal condition
Rings
ELECTRICAL SAFETY

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DE-ENERGIZED THE EQUIPMENT
• Everybody should avoid working on or near live equipment
• De-energized procedure:
1. Barricade the machine / machine area
2. Put warning sign eg under repair
3. Shut down the machine eg use LOTO procedure
4. Start the machine after work
• Live parts on which an employees may be exposed shall be de-
energized unless
– It is not possible due to work requirements
– It is not possible due to equipment design
– The equipment uses 50 volts or less
ELECTRICAL SAFETY

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PREVENTIVE MEASURES AGAINST ELECTRIC SHOCK
• Protection against direct contact
– Providing proper insulation
• Protection by barriers, enclosure, placing live parts
out of reach
• Protection against indirect contact
– By effective earthing for metallic enclosure
ELECTRICAL SAFETY

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Hazard - Inadequate Wiring
• 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
Wire gauge measures
wires ranging in size from
number 36 to 0 American
wire gauge (AWG)

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Control – Use the Correct Wire
• Wire used depends on operation, building materials,
electrical load, and environmental factors
• Use fixed cords rather than flexible cords
• Use the correct extension cord
Must be 3-wire type and designed for hard or extra-hard use

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Hazard – Defective Cords & Wires
• Plastic or rubber
covering is
missing
• Damaged
extension cords
& tools

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Hazard – Damaged Cords
• 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

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Control – Cords & Wires
• Insulate live wires
• Check before use
• Use only cords that are 3-wire type
• Use only cords marked for hard or extra-
hard usage
• Use only cords, connection devices, and
fittings equipped with strain relief
• Remove cords by pulling on the plugs,
not the cords
• Cords not marked for hard or extra-hard
use, or which have been modified, must
be taken out of service immediately

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Permissible Use of Flexible Cords
Stationary
equipment-to
facilitate
interchange
DO NOT use flexible wiring where
frequent inspection would be
difficult or where damage would be
likely.
Flexible cords must not be . . .
• run through holes in walls, ceilings,
or floors;
• run through doorways, windows, or
similar openings (unless physically
protected);
• hidden in walls, ceilings, floors,
conduit or other raceways.

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Grounding
Grounding creates a low-
resistance path from a tool
to the earth to disperse
unwanted current.
When a short or lightning
occurs, energy flows to the
ground, protecting you
from electrical shock,
injury and death.

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Hazard – Improper Grounding
• Tools plugged into improperly
grounded circuits may become
energized
• Broken wire or plug on extension
cord
• Some of the most frequently
violated OSHA standards

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Control – Ground Tools & Equipment
• Ground power supply systems, electrical
circuits, and electrical equipment
• Frequently inspect electrical systems to
insure path to ground is continuous
• Inspect electrical equipment before use
• Don’t remove ground prongs from tools
or extension cords
• Ground exposed metal parts of
equipment

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Control – Use GFCI (ground-fault circuit
interrupter)
• 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
• Use GFCI’s on all 120-volt, single-phase,
15- and 20-ampere receptacles, or have
an assured equipment grounding
conductor program.

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Control - Assured Equipment
Grounding Conductor Program
Program must cover:
– All cord sets
– Receptacles not part of a building or structure
– Equipment connected by plug and cord
Program requirements include:
– Specific procedures adopted by the employer
– Competent person to implement the program
– Visual inspection for damage of equipment connected by
cord and plug

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Hazard – Overloaded Circuits
Hazards may result from:
• Too many devices plugged into a
circuit, causing heated wires and
possibly a fire
• Damaged tools overheating
• Lack of overcurrent protection
• Wire insulation melting, which
may cause arcing and a fire in the
area where the overload exists,
even inside a wall

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Control - Electrical Protective Devices
• Automatically opens circuit if
excess current from overload or
ground-fault is detected –
shutting off electricity
• Includes GFCI’s, fuses, and circuit
breakers
• Fuses and circuit breakers are
overcurrent devices. When too
much current:
 Fuses melt
 Circuit breakers trip open

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Power Tool Requirements
• Have a three-wire cord with
ground plugged into a grounded
receptacle, or
• Be double insulated, or
• Be powered by a low-voltage
isolation transformer

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Tool Safety Tips
• Use gloves and appropriate footwear
• Store in dry place when not using
• Don’t use in wet/damp conditions
• Keep working areas well lit
• Ensure not a tripping hazard
• 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

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Preventing Electrical Hazards - Tools
• Inspect tools before
use
• Use the right tool
correctly
• Protect your tools
• Use double insulated
tools Double Insulated marking

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Temporary Lights
Protect from contact and damage, and don’t
suspend by cords unless designed to do so.

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Clues that Electrical Hazards Exist
• 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

84
Lockout and Tagging of Circuits
• 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 equipment or
circuits being worked on

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Safety-Related Work Practices
To protect workers from electrical shock:
– 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

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Safety-Related Work Practices
• Use special insulated tools
when working on fuses with
energized terminals
• Don’t use worn or frayed
cords and cables
• Don’t fasten extension cords
with staples, hang from
nails, or suspend by wire.

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Preventing Electrical Hazards -
Planning
• Plan your work with others
• Plan to avoid falls
• Plan to lock-out and tag-out equipment
• Remove jewelry
• Avoid wet conditions and overhead
power lines

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Avoid Wet Conditions
• If you touch a live wire or other electrical
component while standing in even a small
puddle of water you’ll get a shock.
• Damaged insulation, equipment, or tools
can expose you to live electrical parts.
• Improperly grounded metal switch plates
& ceiling lights are especially hazardous in
wet conditions.
• Wet clothing, high humidity, and
perspiration increase your chances of
being electrocuted.

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Preventing Electrical Hazards - PPE
• Proper foot protection
(not tennis shoes)
• Rubber insulating gloves,
hoods, sleeves, matting,
and blankets
• Hard hat (insulated -
nonconductive)

90
Preventing Electrical Hazards – Proper
Wiring and Connectors
• Use and test GFCI’s
• Check switches and insulation
• Use three prong plugs
• Use extension cords only
when necessary & assure in
proper condition and right
type for job
• Use correct connectors

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Training
• Deenergize electric equipment before inspecting or repairing
• Using cords, cables, and electric tools that are in good repair
• Lockout / Tagout recognition and procedures
• Use appropriate protective equipment
Train employees working with electric equipment in safe work practices,
including:

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Summary – Hazards & Protections
Hazards
• Inadequate wiring
• Exposed electrical parts
• Wires with bad insulation
• Ungrounded electrical systems and tools
• Overloaded circuits
• Damaged power tools and equipment
• Using the wrong PPE and tools
• Overhead powerlines
• All hazards are made worse in wet
conditions
Protective Measures
• Proper grounding
• Use GFCI’s
• Use fuses and circuit
breakers
• Guard live parts
• Lockout/Tagout
• Proper use of flexible cords
• Close electric panels
• Training

93
Summary
Electrical equipment must be:
– Listed and labeled
– Free from hazards
– Used in the proper manner
If you use electrical tools you must be:
– Protected from electrical shock
– Provided necessary safety equipment

94
• Sufficient means of protection by automatic disconnection
of supply from excess current due to overload, short-circuits
must be fitted
– Fuses should be used with correct rating
– Residual current circuit breaker (RCCB) is an excellent
means of protection fitted between plug and the mains
– Earth leakage circuit breaker (ELCB) is required to be used
together with extension wire in premises (e.g. INTEL
standard is 0.01mA).
ELECTRICAL SAFETY

95
ELCB
RCCB
ELECTRICAL SAFETY

96
Electrical Safety Products
• ELCB (Earth Leakage Circuit Breakers) or GFCI
(Ground Fault Circuit Interrupters) – 5 mA
• Residual Current-Operated Circuit Breakers (RCCBs)
– 30, 100, 300 mA
• Arc Fault Current Interrupters (AFCIs) – to detect
arcing faults not detected by RCCB
• Glowing Connection Detectors (GCDs) – to detect
loose connections at socket terminals which cause glowing
connections
• Infra-Red Hotspot Detection Tool – Hotspot surveys on
critical terminals and equipment
• Thermography Surveys

98
LOCKOUT/TAGOUT
• Locks are placed on equipment
power supply to prevent inadvertent
energization
• One person, one lock, one tag
– Individual working on the
equipment must install his own
lock and tag
– Group lockouts are not allowed
• The lockout tag provides a warning
and identifies the person who placed
it
ELECTRICAL SAFETY

99
EQUIPMENT SHUTDOWN
• Shut the system down by using its
operating controls
• Follow whatever procedure is right
for the equipment, so that you
don’t endanger anyone during
shutdown
ELECTRICAL SAFETY

100
EQUIPMENT ISOLATION
• Operate all energy – isolating
devices so that the equipment is
isolated from its energy sources
• Be sure to isolate all energy
sources – secondary power
supplies as well as the main one
• Never pull an electrical switch while it
is under load
• Never remove a fuse instead of
disconnecting
ELECTRICAL SAFETY

101
GENERAL ELECTRICAL SAFETY REQUIREMENT (1)
• All accessible parts of electrically – operated equipment
should be efficiently earthed
• All flexible cords, plugs, sockets and couplers should be of
good quality and standard
• Main input switches should be suitably placed on
equipment with the “ON” and “OFF” positions identified
and accessible
ELECTRICAL SAFETY

102
• Equipment should be regularly inspected and serviced,
and staff should be encouraged to report defects
• Before anyone attempts to repair, service or adjust any
electrically operated machine or equipment, or to remove
covers, it should be disconnected from the power supply
ELECTRICAL SAFETY

103
• Circuit should not be overloaded, particularly by the use
of a single socket outlet for more than one item of
equipment
• Staff should be trained in safety procedures and treatment
in the event of electric shock
ELECTRICAL SAFETY

104
GENERAL ELECTRICAL
SAFETY REQUIREMENT (4)
• Electrical equipment and
machines must be earthed.
• Small portable electric
machines, for example drills
can be double insulated
instead
ELECTRICAL SAFETY

105
EFFECT OF ENVIRONMENTAL CONDITIONS
• All electrical equipment must be adequately protected from
any adverse effects of the environmental or other danger,
such as weather, wet, heat, dirt and dust, corrosive
conditions, flammables or explosives
ELECTRICAL SAFETY

106
PPE
• Safety rubber shoes
• Insulated gloves
• Safety glass
• Hard hat
• Non-conductive floor mat
• Tight sleeves and trouser
legs
ELECTRICAL SAFETY

107
Gloves
Insulated for working with
electricity
PPE
ELECTRICAL SAFETY

108
The sole and heel are made
of a tough rubber
compound with no exposed
metal to conduct electricity
Electrostatic Dissipating Shoes
(EDS). Used in and near high-
tech electronics and flammable
or explosive atmospheres. They
conduct built-up static charge to
a grounded floor
PPE
ELECTRICAL SAFETY

109
HARD HAT SAFETY GOGGLE
PPE
ELECTRICAL SAFETY

110
INSULATED TOOLS
ELECTRICAL SAFETY

111
EMERGENCY RESPONSE FOR ELECTROCUTION
• Asses the situation
• Take precautions to protect yourself and anyone else in the
vicinity
• Free the victim from the electricity
– Cut-off the electricity supply, if action could be taken
immediately – off the switch, remove the plug, etc
– If not, dry cloth, rope or belt could be slipped round the
victim’s leg to pull the victim way
ELECTRICAL SAFETY

112
• Move the victim to a safe area and
access their injury
• Use a dry, non-conductive object
such as a:
–Wooden chair
–Broom handle
–Plastic pipe
–Rope
to safe / free the victim
• Perform first-aid if you are trained to
do so
• Seek urgent medical attention
EMERGENCY RESPONSE FOR
ELECTROCUTION
ELECTRICAL SAFETY

113
GET HELP AND NOTIFY
SECURITY
For example, INTEL:
1. Ext 4000-security
2. Ext 3000-emergency
EMERGENCY RESPONSE FOR
ELECTROCUTION
ELECTRICAL SAFETY

114
Keep the person warm & down
Stay with victim
EMERGENCY RESPONSE
ELECTRICAL SAFETY

115
Summary – Hazards & Protections
Hazards
• Inadequate wiring
• Exposed electrical parts
• Wires with bad insulation
• Ungrounded electrical systems and tools
• Overloaded circuits
• Damaged power tools and equipment
• Using the wrong PPE and tools
• Overhead powerlines
• All hazards are made worse in wet
conditions
Protective Measures
• Proper grounding
• Use GFCI’s
• Use fuses and circuit
breakers
• Guard live parts
• Lockout/Tagout
• Proper use of flexible cords
• Close electric panels
• Training

6a_ELECTRIC SAFETY.ppt

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