CHECK OUT WHY IN A THREE PIN PLUG THE EARTH PIN IS THICKER AND LONGER THAN OTHER PINS!!

When we use electrical appliances with metal bodies, we require protection against possible electric shock. If there is a fault current (leakage) inside the appliance, the whole metal case becomes live. If you happen to touch it, a current will flow through you to the earth (ie. electric shock). 

Hence, to prevent electric shock, we need to ensure that the system is properly earthed (= 'grounded'). This way if you touch a faulty appliance, you don't get electrocuted!

So, why is the earth pin made bigger?

1. The earth pin on a plug is longer than the live and neutral pins. This means the earth pin is the first to connect and the last to disconnect. 

• When inserting the plug, the earth connection is made before the current carrying contacts of the plug become live.
• When withdrawing the plug, the current carrying contacts shall separate before the earth connection is broken.

Thus, the earthing connection is always maintained to improve safety.

2. Many wall sockets have safety shutters (see image) on the live and neutral lines to prevent children from inserting conducting materials which may result in electric shock. Insertion of a longer (earth) pin helps in opening the shutters, facilitating the insertion of other two pins. These are called Earth-pin operated shutters.

3. Though it is impossible to insert the plug into the socket upside down, one may try to insert the plug top in a misaligned position (for e.g. trying to insert the earth pin into the phase socket with the other two pins further down out of the socket). Hence, the earth pin is made thicker so that even by mistake it cannot be inserted into the live or neutral hole of the socket. This prevents earth pin from establishing an electrical contact with the live terminal.

As we can see, every effort is taken to protect you from electric shock.

DIFFERENCE BETWEEN FAN AND BLOWER EXPLAINED !!

The fan and blower are two different kind of machine belonging to same group. Both these machines are used to flow a gas or mostly air in a large area but the main difference between fan and blower is that the fan operates at low pressure while blower operates at high pressure.

These machines are used in many industrial machines for air conditioning or cooling purpose.

The fan consists a rotor which is equipped with some blades. This rotor rotates by an electric motor or sometimes by a mechanical machine. It is primary used to flow the air into a large space. Mostly fans are used to blow the air axially or the direction of the air flow along the axis of the rotor. Fans blow large volume of air with minor change in pressure. It has specific pressure ratio is 1.1.

                               

Blower is different from fan. It is a centrifugal unit which blows the air radially. It consists of a impeller equipped with series of blades which are designed to flow air radially. It blows the air or gas with a moderate pressure change. The change in specific pressure ratio is 1.11 to 1.2.

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OIL COOLED ENGINE EXPLAINED !!

The term oil cooler and oil cooling became very popular in India after launching the Pulsar series 200 (discontinued) and 220 F from Bajaj motors. Oil cooling as we know from the name itself is cooling of engine oil by help of a special component called an oil cooler. Generally an engine oil will loose its viscosity if temperatures are very high than its specified heat range. As a result it may not be able to lubricate the mechanical components properly as specified. To overcome this problem and to provide better cooling especially for air cooled high performance engines oil coolers are generally used.

Oil cooling is a way apart from liquid cooling mainly in the following aspects,

* It does not maintain a constant temperature like a liquid cooled engine.

* It does not have a thermostat, bypass system and cooling fan but instead uses a small radiator alone.

* Cost wise it is very economical because of simplicity and components involved.

The oil pump which is normally used in  a conventional engine pumps and circulates oil for lubrication (forced lubrication) to all parts in a particular circuit. It starts from the crankcase and ends back in the crankcase after lubrication. 

Where as in oil cooling it reaches a radiator fixed outside from a centrifugal filter, cooled and then circulated back to the engine.

CONS:

As already told it cannot maintain a steady engine temperature like liquid cooling. The oil flow to radiator is not controlled by any thermostat like a coolant controlled by a liquid cooled engine and engine oil begins to flow to the radiator as soon as the engine is fired up.  

During heavy start, stop traffic and idling where there is minimal airflow this system loses its potential but it provides better cooling when there is a steady air flow while riding and in long run. Hence a liquid cooled engine offers better engine cooling and performance than an air cooled engine. This can also improve the life of engine oil as well.

On the whole its a cost effective way to improve cooling system especially for an air cooled engine.