Difference between AC & DC
Single Phase AC
Three Phase AC
Resistance, Reactance and Impedance
Facets of Energy
Sources of Generation
Generation of Electricity
Constructional Features of PT
Net & Gross Metering
Fuse Wire Table
Size of Earth lead
Size of Earth lead
Station Battery Maintainence
Calculation of VR
11KV UG cable VR
Calculation of Power loss and VR
Basic checks of Relays
BEE Star Labels
Electricity as a cause of fire:
Electricity may cause a fire due to following reasons:
Loose joints in the electric lines.
Flow of high current in the low capacity wires.
Use of high current capacity fuse in comparison to the load.
Use of ordinary wire fuses which cause spark or fire during blowing off.
Short circuit in the live wires.
Overheating of an electrical apparatus
Safety precautions in case of electric fire:
Switch off the main switch.
Extinguish the fire by throwing dry sand.
Before using a fire extinguisher, make sure that is not out-dated and it is of carbon dioxide type or carbon tetra chloride type and meant for electric fires.
Do not us water to extinguish the fire if the main line is live.
Carbon Dioxide Extinguisher:
Contains liquid carbon dioxide.
When released the carbon dioxide forms flakes that vaporize and blanket the fire.
Used for electric fire.
Carbon tetrachloride extinguisher:
It comprises a cylindrical metal container containing carbon tetrachloride liquid. When released, it turns into a vapour that is heavier than air and thus settles over the fire Used for electrical fires. Not used in enclosed places, as the vapour is poisonous.
Accidents can happen in spite of all the precautions.
It is necessary to provide first aid to the injured person.
Proper and timely first aid may save life of the injured and reduce suffering.
Elementary first Aid:
Switch off the main switch immediately when a person gets a electric shock.
Release the victims of electric shock.
If the main switch is not in easy approach then use dry wood or any other insulating material to release the victim.
General procedure of giving first aid:
Do not to be panic.
Shift the person to a comfortable position simultaneously calling a doctor or an ambulance.
Do not crowd round the patient, as fresh air is essential.
Close observation on breathing, hemorrhage, burns , fracture and wounds of the patient should be done.
Start giving artificial respiration immediately if breathing has stopped.
Bleeding due to a cut of artery is serious and can cause sufficient loss of blood.
By applying pressure to the correct point using a kerchief or some other cloth the bleeding can be stopped.
Burns caused by electric flashes, hot liquids and flames should be covered with sterile dressing and then bandaged.
Acid and alkali burns should be washed with a large quantity of water as soon as possible and then a sterile dressing and bandage may be applied.
Fractures should be handled carefully.
No attempt should be made to straighten the fractured part.
Wounds with scratches and abrasions are minor injuries.
These should first be washed and then covered with a sterile dressing when dry.
Puncture wounds, caused by pointed objects such as nails and ends of wires should be covered with a sterile dressing.
Never give water or any other liquid to an unconscious person, but if the injured person is conscious and has sustained no abdominal injury, water, tea or coffee may be given to drink.
In severe case, do not let the patient know that he is badly hurt or let him see his own injury.
Do not attempt to do too much, do the minimum that is essential.
Do not remove that patient’s clothes unless essential.
Remove the patient to the care of a doctor as soon as possible.
It is an important part of First Aid.
This is the act of restoring consciousness or life of the victim.
Electric shock victims with abnormal working of heart, disappeared pulse and no breathing can be considered almost dead.
In such cases proper resuscitation can revive many victims.
Artificial respiration is the main action of the resuscitation process.
Methods of Resuscitation:
This is also called Back Pressure arm lift method or Holger Nielsen method.
Mouth to mouth resuscitation:
Mouth to nose resuscitation:
Close the mouth and blow the air through the nose.
Pole top resuscitation:
Done when the person gets shock on the Pole.
Move to Top