Pages

Wednesday, 2 May 2012

Electrical Safety

Electrical safety in industry/house
                                                                
Electrical hazard:
Electricity is considered as hazardous/dangerous due to following reasons-
·         Overloading or short circuiting may lead to a fire.
·         Touching to a live wire gives a severe electric sock. Such   electric sock may lead to fatal accident.
·         Broken / damaged and defective switch /socket may lead to an electric shock to the user or it may cause fire due to spark.

Safety precaution while using electricity
·         Never touch/handle any electrical appliance with wet hands. Wet body acts as conductor
·         Never try to pull away a person who is victim of a live wire.

Care to be taken for:
Wiring: all wires used in electrical circuit should be covered with good insulators.
Joints in wires: all wire/electrical joints should be covered with insulation tape.
Electrical connection: all electrical connections at switches, plugs, sockets and junction must be tight properly.
Repair/replacement: defective switches, sockets or wires should be replaced immediately. Whenever any maintenance job is required; put on rubber gloves and rubber shoes, or stand on a dry wooden stand. Before staring maintenance job, the main switch should be switched off. The testers, screw drivers, pliers and other repairing tools have proper insulation on them.
Fuse/MCB: each circuit should have a fuse or MCB of proper rating. Fuse should be connected to the live wire. Lighting circuit (6Amperefor bulbs, fans, tubes etc) and power circuit (16Ampere for heaters, cooler, air conditioners, geysers etc) should be connected with separate MCB
ELCB: ELCB should be provided in main circuit with proper rating to isolate the power in case of fault or fire. Consult an expert or bonafied electrician.
Earthing: all electrical appliances must be properly earthed. By proper earthing, the danger of any electrical accident shock may be reduced.
Handling: while using an electrical appliance, hold it from its handles made of any insulating material. One should not touch the metallic body of any electrical appliance such as heater or electric iron while switched on.
Dealing with accident: in case of any short circuiting, or any accidental contact of a person with a live wire, do as follows:
·         Immediately switch off the main switch.
·         Provide him/her a support of some non conducting material such as rubber, sheet or wood.

Wire color code:
Live –RED, YELOLW, BLUE
Neutral-BLACK
Earth -GREEN

Typical house wiring-

                        
                                                      

SAFETY TERMINOLOGY
Shocks-Results in burn, injury,
Flashovers- fires, damages, Results in deaths
Faults-Results in arching, explosions and fires
Explosions in electrical equipment resulting in damage to installations and deaths
Fire hazards resulting in destruction, loss of fire and release of smoke, dust gases etc.  

                                      















  

Causes of electrical hazard   
                          
       Exposed live conductors
       Conductor not discharged
       Enclosure not earthed
       Lack of fence and lock
       Lack of awareness
       Miscommunication /miss-interpretation
       Capacitor not discharged
       Lack of ‘danger sign’.
       Open cable trench
       Cable not clamped properly
       Poor illumination
       Overloading of electrical gadgets
       Not using safety belt
       Internal flash over
       Protection did not respond.
       Lightning stroke
Current and voltage effect

                                   










Shock level at 50 Hz

Below 10 mA amperes
Not painful
10mA to 15mA
Painful shock
15mA to 20 mA
Muscle control affected
20 mA to 40 mA
Breathing affected
40mA to 80mA
MAGNITUDE OF CURRENT
Above 100mA
Severe burn, leads to death

Safety device
      Discharged rod
      Rubber gloves
      Rubber shoes
      Insulation mat
      Insulation support
      Insulated pliers/screw driver
      Goggles/apron
Electrical permit
      Line clearance for Low Voltage
      Line clearance for High Voltage
      Height work permit
      Excavation permit
      Temporary connection permit
      Barricading
Tagging
      Green tag for other than electrical
      Red tag for electrical isolation
      Tag “MAN AT WORK”
      Message no for de-energization
      Message no for energization 
Earthing system
      Structure earthing
      Tower earthing
      Cabinet earthing
      Equipment earthing
      Transformer body earthing
      Transformer neutral earthing
      Surge arrester earthing
      Cable rack earthing
      Fencing/door earthing

3 comments:

  1. Wow!
    Nice Blog for the Blogging.Electrical safety is the impotent and useful topic and it's very impotent for us.I think you have the huge knowledge about Electrical hazard.Good to know about your blog i have read your article and i am very inspired from you ideas i will visit very soon again with new ideas hope you soon update your blog with new and latest info.
    Earthing Equipment

    ReplyDelete
  2. Electrical safety is really important for us all. We should know what to do, what not to do, etc. You should consult your local electrician those who have their electrical continuing education for any electrical tips.

    ReplyDelete
  3. It is informative post. Ensure all power outlets and switches have faceplates covering the wiring. Exposed wiring is a shock hazard.

    bolt bins

    ReplyDelete