WORKSHOP PRACTICE

1
WORKSHOP PRACTICE

• Lab No. 3
• Electrical Accidents Safety Precautions

2
Todays Lab

• What is an Electrical Accident?
• How to avoid Electrical Accidents?
• Safety Precautions
• Safety Regulations
• Safety Signs

3
Electrical Accident

• Any unwanted action which takes place in a
  maximum of three seconds is referred to as an
  accident.
• If due to any reason current starts flowing in
  the human body then an electrical accident is
  said to have taken place.

4
Electric Shock

• Electrical shock occurs when a person comes in
  contact with two conductors of a circuit or when
  the body becomes part of the electrical circuit.
• In either case, a severe shock can cause the
  heart and lungs to stop functioning. Also, severe
  burns may occur where current enters and exits
  the body.

5
Electrical Accident

• Human body receives shock
• Time up to 10 seconds
• Two types of waves produced
• Electrostatic Waves
• Electromagnetic Waves

6
Types of Waves

• Electrostatic Waves (ESW)
• If the current is flowing through a conductor,
  it will produce Electrostatic waves.
• Electromagnetic Waves (EMW)
• If we have two parallel conductors and current is
  flowing through them, then electromagnetic waves
  are produced between these conductors.

7
Ranges of Resistance

• The electric wire insulation has a resistance up
  to 3 MO.
• Human body resistance ranges (1400-2000)O.
• During electric shock, resistance decreases to 10
  O.
• Heavy current flows through human body.

8
Effects of Shock on Human Body

• Due to decrease in human body resistance heavy
  current flows.
• It damages the cardiac and respiratory systems.
• Paralysis Problem

9
Three Phase Voltages

• In power house 3-phase voltages are generated.
• The three phases are equal in magnitude but out
  of phase by 120o each.
• 3-Phase Configurations
• Star Configuration.
• Delta Configuration.

10
Types of Electrical Accidents

• Phase to Ground (Single Phase)
• When human body touches phase line while standing
  on the ground.
• Phase to Phase (Double Phase)
• When human body touches two phases.
• Three Phase
• When human body is in contact with 3 phases at a
  time.

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How to avoid Electrical Accidents

• Respect all voltages
• Prevention is the best medicine for electrical
  shock.
• Do not take chances.
• Have a knowledge of the principles of electricity
  and follow safe work procedures.

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Safety Precautions

• A safety precaution is a measure that you take to
  avoid any injury/ harm to either yourself or
  anyone/thing in your surroundings.
• Be careful.
• Use common sense
• A commodity which the legislators think is in
  short supply and not very common.
• Stop and think before you act.
• Ask the technical staff for advice.

13
Workshop Safety Precautions

• Protective Equipment
• Use goggles and breathing masks.
• Tidiness
• Dispose of sharp objects, blades, glass shards
  in suitable containers - Ensure the workshop is
  tidy.
• Machinery
• Make sure machinery is properly installed,
  levelled and are periodically maintained or
  serviced.

14
Clothing and Personal Protective Equipment
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Safety Precautions to avoid Electrical Accidents

• Dont touch the person who is still in contact
  with live conductor.
• Live wire connection.
• Grounding.
• Insulation strength.
• Plug point disconnection.
• Switches-to avoid open, unprotected ends of wire.
• Use fuses other protective devices to avoid
  damage to the equipment.

16
Grounding

• To connect the neutral of an electrical system to
  the ground is called grounding.
• Electrical equipment safety.
• Internal and external factors make the electric
  system unbalance, to avoid this distortion and
  damage to the system.

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Safety Regulations

• Insulation
• It is a material which does not allow the flow of
  electrons.
• Dielectric strength of the insulation.
• Grounding
• Electrical equipment should be properly grounded.
• Equipment Status
• Good condition
• Use proper equipment for the job.
• Personal Experience
• Any person, whether experienced or not, involved
  in an activity is called personal.
• Experience is of great importance.

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Safety Regulations

• Personal Mental Condition
• Sound mental condition.
• Should not be mentally disturbed.
• Personal Knowledge
• Should be properly trained for the activity, he
  has to perform.
• Ambient Conditions
• The conditions under which the equipment works
  efficiently.
• Current rating, Voltage rating, Frequency,
  Temperature.

19
Who to do when an electrical accident has
occurred?

• Free the victim from contact with the electricity
  in the quickest, safest way. This step, while it
  must be taken quickly, must be done with great
  care otherwise, there may be two victims instead
  of one.

20
First aid for Electric Shock

• Sometimes victims of electrical shock suffer
  cardiac arrest or heart stoppage as well as loss
  of breathing.
• The process by which a person who has stopped
  breathing can be saved is called artificial
  ventilation (respiration).
• The purpose of artificial respiration is to force
  air out of the lungs and into the lungs, in
  rhythmic alternation, until natural breathing is
  reestablished.

21
Clean up your mess!

• It is the responsibility of ALL Laboratory and
  Workshop users to keep the surrounding work area
  clean and tidy at all times.
• At the end of the session, everyone is supposed
  to bring the equipment in their proper places.

22
Safety Signs

• Safety Signs are the symbols which
• Prevent accidents.
• Signal health hazards.
• Indicate the location of safety, first aid and
  fire protection equipment

23
Safety Signs

• Stop and Prohibition Sign

• Caution (Warning) Sign

24
Safety Signs

• Mandatory (must obey) signs

• Emergency-related information signs

25
Lab Report Format

• Experiment No. 2
• Title To study Vernier Caliper, Micrometer, SWG
  and to measure diameter of different wires and
  depth of different items.
• Apparatus
• Theory
• Figure/ Circuit Diagrams
• Procedure
• Observations Calculations
• Conclusions/ Comments

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Lab Report Submission

• Last date of submission of Lab 1,2 3 is
  Monday,9th November till 100 p.m. in Workshop
  Lab.