WHAT IS THE HEAT EFFECT OF ELECTRIC CURRENT:
When current passes through a conductor heat is produced. This is in fact the work that is required to be done is sending the current against the resistance, which is converted into heat.
Heat produce in the conductor is directly proportional to :
• Square of the current passing through conductor 12
• The resistance of the conductor 'R' and
• The time of flow 't'
Combining the proportionality, we get,
H = 0.24121RT
Where, 'H' is heat produced in calories, 'T' is current in ampere resistance on ohm and 't' is the time of flow in second.
The phenomenon is particularly important to Firefighter as so produce if not dissipated safety, will raise the temperature ultimately ignites the combustible materials available in the near.
What are Conductor & Insulator?
Conductors are the materials which allow the flow of e.g. through them with least resistance, e.g. Copper, Alluminium, Iron, Water where is the internet hazaar the materials which do not allow the electrons through them. E.g. wood ( dry ), rubber, plastic, glass, mi.
Generation and Distribution of Electricity:
The bulk production of electricity is done by converting other of energy voz, heat and potential energy at place which are known power station. In india, the most common power plant include,
- Thermal power station
- Hydro-power station
- Nuclear power station
In a thermal power station coal is bruned to produce heat e.g. which is utilised in converting water into steam ( temperature about and pressure 150 kgf/cm2 ) which in turn runs the steam turoine the converting the pressure energy is further utilised in rotation the general produce electrical energy.
In hydro power station water is connected at her attitude when allowed to flow at lower level discharge water at high pressure, high pressure flow rotates the water turbine converting the pressure into mechanical energy which is subsequently utilise for running generator to produce electrical energy.
In a Nuclear power station, fissin reaction in a radio electro material allowed to take place in nuclear reaction which provides heat energy. This heat energy is used in converting water into stable running the turbine which gives mechanical energy. The mechanical energy so produce is used in running the generator to produce electricity.
The electricity produce at either of the three power station is a low pressure ( voltage ) current and since, for distributing electricity at distance places, high pressure ( voltage ) ignrequired and electrical equipment, namely transformer are used to increase the pressure and then through transmission lines electricity is transmitted to distance place. Since, low pressure ( voltage ) current is the requirement of the consumer. Hence, wherever tapping done stop down transformer are used to reduce the voltage depending upon the consumer requirement and then supplied to the users. Step up transformers are used at generating station where is step down transformer are you sad electrical sub-station.
Fire hazards of electrical origin maili due to the in proper use of electricity in proper electrical installation and let of arc in the maintenance of the electrical system and decorate fir mostly originated mostly from the sparx offer heating of electrical equipment switch maybe cause by the following :
- Short circuitcircuit
- of insulation
- Overheating of Electrical equipment
- Improper selection of equipment/wiring
- Loose electrical contacts
- Discharge of static charge.
With few exceptions most of the fire originated by electricity can be prevented by :
- Selecting the proper rating electrical equipment and wiring
- Avoiding the excess loading of Electrical equipment
- Using proper capacity fuse/circuit breaker
- Ensuring effective earthing of Electrical equipment and in installation
- Periodic inspection and testing of electrical circuit and equipments.
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