Safe work practices

The following practices may reduce risk of injury or fire when working with electrical
equipment:

1. Keep away from the energized or loaded circuits.

2. Sources of electricity and exposed circuits must be guarded.
3. Disconnect the device from the source in the period of service or maintenance of the
device.
4. Disconnect the power source before servicing or repairing electrical equipment.
5. Handling the equipment that is plugged in, if it is necessary, hands or contacting parts
must be dry and, wear non-conductive gloves and insulated-soles shoes.
6. If it is safe to work with only one hand, keep the other hand away from all conductive
material. This step reduces accidents that result in current passing through the chest
cavity.
7. Utilization of electrical equipment in cold rooms must be minimized due to
condensation issues. If it is imperative to use such areas, the equipment must be
fixed on a wall or vertical panel.
8. If the device interacts with water or other liquid chemicals, equipment must be shut
off power at the main switch or circuit breaker and unplugged.
9. If an individual comes in contact with a live electric, do not touch the equipment,
source, cord or individual. Disconnect the power source from the circuit breaker or
pull out the plug using a leather belt.

Common Causes of Electrical Accidents and Prevention

The major hazards associated with electricity are

 Electric Shock:
o This occurs when electric current passes through the body. The severity
depends on the current's path, strength, and duration.
o Even low-voltage shocks can be dangerous, especially in wet conditions or if
the current passes through vital organs.
 Electrical Burns:
o These can be external or internal, caused by the heat generated by electric
current.
o Internal burns can be particularly severe, as they may damage tissues and
organs without visible external signs.
 Electrical Fires:
o Overloaded circuits, faulty wiring, and malfunctioning appliances can generate
excessive heat, igniting nearby materials.
o Electrical fires require specialized extinguishing methods, as water can
conduct electricity.
  Arc Flash/Arc Blast:
o This is a dangerous release of energy caused by an electrical fault.
o It produces intense heat, light, and pressure waves, which can cause severe
burns, blindness, and other injuries.

common Causes of Electrical Accidents:

 Contact with Overhead Power Lines:

o This is particularly prevalent in construction and other outdoor work.
o Operating machinery or equipment too close to power lines is a major risk.
 Faulty Wiring and Equipment:
o Damaged insulation, frayed wires, and loose connections can expose live
conductors.
o Malfunctioning appliances and tools pose significant hazards.
 Inadequate Grounding:
o Proper grounding provides a safe path for electrical current, preventing
shocks.
o Lack of or improper grounding increases the risk of electrocution.
 Contact with Energized Parts:
o Accidental contact with live electrical components can result in severe shocks
and burns.
o This can occur during maintenance or repair work.
 Water and Moisture Exposure:
o Water significantly increases the conductivity of electricity.
o Using electrical appliances in wet environments is extremely dangerous.
 Lack of Proper Safety Training:
o Insufficient knowledge of electrical hazards and safety procedures contributes
to accidents.
o Workers need to be properly trained to recognize and avoid electrical risks.
 Overloaded Circuits:
o Overloading circuits can cause overheating, leading to fires and electrical
shocks.
o Using too many appliances on a single circuit is a common cause.
 Improper use of extension cords:
o "Daisy chaining" extension cords, using damaged cords, and using indoor
rated cords outdoors are all common mistakes.

Prevention Measures:

 Regular Inspections and Maintenance:

o Regularly inspect electrical wiring, equipment, and appliances for damage.
o Perform routine maintenance to ensure proper functioning.
 Proper Grounding:
o Ensure all electrical systems and equipment are properly grounded.
o Use ground-fault circuit interrupters (GFCIs) in areas prone to moisture.
 o
 Lockout/Tagout Procedures:
o Implement lockout/tagout procedures to de-energize electrical circuits before
maintenance or repair work.
o This prevents accidental energization.
 Use of Personal Protective Equipment (PPE):
o Use appropriate PPE, such as insulated gloves, footwear, and clothing.
o This provides an extra layer of protection against electrical hazards.
 Safety Training:
o Provide comprehensive safety training to all workers who may be exposed to
electrical hazards.
o Educate them on hazard recognition, safe work practices, and emergency
procedures.
 Safe Work Practices:
o Keep electrical equipment away from water.
o Avoid overloading circuits.
o Use extension cords properly.
o Always treat electrical circuits as if they are live.
 Awareness of Overhead Power Lines:
o Maintain safe distances from overhead power lines.
o When working near them, have power lines de-energized or insulated if
possible.
 Use qualified Electricians:
o When electrical work needs to be performed, use only qualified and licensed
electricians.

By understanding the causes and implementing these preventive measures, you can
significantly reduce the risk of electrical accidents.

Key Safety Devices:

 GFCIs (Ground-Fault Circuit Interrupters): These devices detect ground faults

and quickly shut off power to prevent electric shock.
 AFCIs (Arc-Fault Circuit Interrupters): These devices detect arc faults, which can
cause electrical fires.
 Circuit Breakers and Fuses: These devices protect circuits from overloads and short
circuits.

Workmen's safety devices

When it comes to electrical safety for workmen, the focus is on preventing electric shock,
burns, and arc flash injuries. Here's a breakdown of essential electrical safety devices:

Personal Protective Equipment (PPE):

 Insulated Gloves:
 o These are critical for protecting hands from electric shock. They are rated for
specific voltage levels, and regular testing is essential.
 Insulated Footwear:
o Safety shoes or boots with non-conductive soles prevent electric current from
traveling through the body to the ground.
 Arc Flash Clothing:
o Flame-resistant clothing, including jackets, pants, and hoods, protects against
the intense heat and energy of an arc flash.
 Face Shields and Safety Glasses:
o These protect the face and eyes from arc flash and flying debris.
 Electrically Rated Hard Hats:
o These provide head protection from impacts and electrical hazards.

Safety Equipment and Tools:

 Voltage Detectors:
o These devices are used to verify that circuits are de-energized before work
begins.
 Ground Fault Circuit Interrupters (GFCIs):
o GFCIs detect ground faults and quickly shut off power, preventing electric
shock.
 Lockout/Tagout Devices:
o These devices are used to de-energize and lock electrical equipment during
maintenance and repair, preventing accidental energization.
 Insulated Tools:
o Screwdrivers, pliers, and other tools with insulated handles provide protection
against electric shock.
 Insulating Mats:
o These mats provide an insulating barrier between the worker and the ground.
 Rescue Rods:
o These are used to safely remove a person from contact with a live electrical
conductor.
 Earthing and Short Circuiting Kits:
o These kits are used to safely discharge and ground electrical circuits.

Q. What is electrical shock? Distinguish between primary shock and secondary

shock. Describe how a person gets electric shock and the causes behind severity
of shock.

Electricity is dangerously. It can cause deaths and fires. Electric Shock is sudden
stimulation of the nervous system of human body by flow of electric current through a
part of the body. Electric shock is a life threatening situation. Shocks are caused by
direct contact with live conductor or flashover.
 Primary Shock is an electric shock has higher magnitude of shock current and
produces physiological harm. The results of primary shock are: Fibrillation (irregular
heart beat); respiratory tetanus (continuous contraction of muscle.

Secondary Shock is shock has low magnitude of current and does not cause
physiological harm, but has annoying effects involuntary muscle reaction, hair
raising, tickling sensation etc. Result of secondary shock are annoyance, alarm and
aversion and loss of balance due to involuntary muscle reaction.

Occurrence. Electric current flow through human body is essential for producing
shock. Human body gets electric shock when electric current flows through any part
of the body due applied voltage difference across the part. The severity of the shock
depends on magnitude of current and path of the current through body and time
duration. Flow through brain and heart for more than 15 mA are extremely dangerous.

Result of electric shock can differ from simple annoying sensation (secondary
shock), serious burn injuries to sudden death within a few seconds.

Shock may occur : -

 When part of human body bridges two phase wires by direct contact.
 When part of the human body bridges on phase and earth, two phases and earth, by
direct contact.
 When part of the human body bridge, two point of same phase at different potential,
by direct contact when part of the human body touches two point having potential
difference them (due to supply voltage or induced voltage or charged voltage)
 Flashover involving part of human body.

Severity depends on :
 Magnitude of current flowing through parts of the human body (Mill amperes)
magnitude varies with time during substransient state.
 Waveform of the current flowing through the body (DC or 50 Hz AC or
impulse or high frequency)
 Rate of rise of current flow (mA/ms).
 Path of current through human body (through heart/brain or not)
 Time duration of current flow through body (millisecond to few seconds).

Additional important factors are :

 Human tolerance to electric field/current varies from person to person to some
extent.
Capability of the person to withstand the effects of shock, state of heart, brain and
health, previous experiences.
 Phase of heart cycle at the instant of the shock and phase of voltage wave.
 The way in which muscle contracts in relation to conductor.
  Whether body is thrown off by muscle reaction or get attached by muscles
contraction/paralysis.

The effect of electric shock depend the voltage, current and duration and also the path of
Current through the heart is most dangerous.

The resistance of human body (between tip of left hand finger and right hand finger with dry
skin) is of the order of 10 mega ohms. However when the hands are wet the resistance
reduces to < 5000 ohms. Similarly the resistance of the skin of feet is high when dry and low
when wet. Skin with perspiration, skin with cuts/bruises/wounds has relatively low
resistance of the order of < 1000 ohms. Hence wet surroundings, wet skin, dirty skin,
bruised skin are dangerous.

The electric shock of even 50 volts AC can be dangerous in the wet surroundings. Shock is
most serious when the current density at touch surface is high and current flows through the
heart or brain. Several deaths takes place every year due to electric shocks at 230 Volts AC
in residential building and industries. Serious accidents occur particularly in wet
surroundings like bath rooms. Once the person comes on good contact with a live part and is
in touch with wet ground, he/she cannot get separated from the live part as his muscles yet
paralyzed and he get electrocuted.

Explain the method of artificial respiration.

Some of the method of artificial respiration are listed below. All concerned should learn these
methods. Training classes by red cross or home guards should be held occasionally train the
personnel . Charts explaining the various method are available and should be displayed at suitable
places. The important method of artificial respiration are:
1. Schafer prone pressure method.
2. Sivesters method (Arm-Lift, Chest pressure method)
3. Nielson Arm lift back pressure method.
4. Mouth to mouth method.

Duration of these processes is 12 to 15 minute. When the patients begins to breath on his own, the
operation should be synchronized with the natural breathing and continued till be breathes strongly
on his own. Schafers method is recommended also for fractures and drownings cases. -Sivester
method is recommended when person cannot be laid on stomach with chest touching the ground due
to burn injury.

Schafer Prone Pressure Method:

 This method involved positioning the person face down (prone) and applying pressure
to their back to simulate breathing.
 The process involved:
o Placing the person face down with their arms extended.
 o The rescuer kneeling astride the person's back.
o Applying rhythmic pressure to the lower ribs to force air out of the lungs.
o Releasing the pressure to allow the lungs to expand.

Silvester's Method:

 Positioning:
o The person is placed on their back (supine).
o The shoulders are slightly elevated to allow the head to tilt back, which helps
to open the airway.
 The Technique:
o The rescuer kneels at the head of the person.
o The rescuer grasps the person's wrists.
o Inspiration (Inhaling): The rescuer raises the person's arms upwards and
outwards, which expands the chest cavity, drawing air into the lungs.
o Expiration (Exhaling): The rescuer brings the person's arms down and
presses them against the sides of the chest, which compresses the chest cavity,
forcing air out of the lungs.
o This cycle of arm movements is repeated at a rate of approximately 12 to 16
times per minute.
Nielson Arm lift back pressure method

The Nielson Arm-lift Back Pressure method, also known as the Holger Nielsen method, is a
form of artificial respiration that was once widely used. Here's a summary of what it entails:

Key Features:

 Prone Position:
o The person is placed face down (prone).
 Back Pressure:
o The rescuer applies pressure to the person's back to simulate exhalation.
 Arm Lift:
o The rescuer lifts the person's arms to expand the chest and simulate inhalation.

How It Works:

 The method involves a rhythmic cycle of applying pressure to the back and lifting the
arms.
 By pressing on the back, the rescuer forces air out of the lungs.
 By lifting the arms, the rescuer expands the chest cavity, allowing air to enter the
lungs.
Mouth to mouth method.

Purpose:

 To deliver oxygen to the lungs of a person who has stopped breathing or is

experiencing respiratory arrest.

How it works:

 The rescuer creates a seal over the person's mouth and blows air into their lungs,
providing the necessary oxygen.

Key Steps:

 Open the airway:

o Use the head-tilt-chin-lift maneuver. Gently tilt the person's head back and lift
their chin to open the airway.
 Seal the nose:
o Pinch the person's nostrils closed with your thumb and forefinger.
 Create a seal:
o Make a complete seal over the person's mouth with your mouth.
 Give rescue breaths:
o Give two rescue breaths, each lasting about one second.
o Watch for the chest to rise with each breath.

Continue CPR:
  If performing CPR, continue with cycles of chest compressions and rescue breaths
(typically 30 compressions followed by 2 breaths).

CPR, or cardiopulmonary resuscitation, is a life-saving technique that's crucial when

someone's heart has stopped beating (cardiac arrest) or they've stopped breathing. Here's a
summary of modern CPR practices:

Core Purpose:

 CPR aims to keep oxygenated blood flowing to the brain and other vital organs until
emergency medical services arrive.

Key Components:

 Chest Compressions:
o These are the most vital part of CPR.
o Place the heel of one hand in the center of the chest, and the other hand on top.
o Push hard and fast, compressing the chest at least 2 inches (5 cm) deep in
adults, and at a rate of 100-120 compressions per minute.
o Allow the chest to fully recoil after each compression.
 Airway:
o If trained, after 30 compressions, open the airway using the head-tilt-chin-lift
maneuver.
 Breathing:
o If trained, give two rescue breaths, each lasting about one second, and watch
for the chest to rise.
 AED (Automated External Defibrillator):
o If an AED is available, use it as soon as possible. Follow the device's prompts.

Hands-Only CPR:

 For untrained bystanders, hands-only CPR is recommended.

 This involves continuous chest compressions until help arrives.
 This method is very effective, and far better than doing nothing.