Electrical Wiring

There's somewhere for the power to go, so it can't make the magic smoke.

Or, more likely in this particular case:

AC impedance.

Electricity For Beginners is down the corridor, third door on the right. No, not that one, the next one. That's it. Cheerio.

"Electricity For Beginners is down the corridor, third door on the right. No, not that one, the next one. That's it. Cheerio."

No, that door leads to the Abuse Clinic. If you want E.F.B. it's across the hall on the left, right next to Arguments.

http://www.funnyordie.com/videos/be76d3ca8d/argument-clinic-from-monty-python-from-greatest-comedy-sketches

and there I was thinking it was the other door, "How to do your own homework!"....

adityaEI.... sorry my friend..... my question for you is, "could your teacher not help you?"

The Coil acts as a load. The contactor develops the heat which is comparatively less than the SCC heat.

All coils that work at A.C source(like coils of contectors ,motors..etc) have an impedance this impedance is like the working of a resistance in d.c circuit.and also has the same unit (ohms) and you can calculate it by use the OHMS LOW.

imped.= Va.c/Ia.c .which Va.c ,Ia.c are the components of the voltage and current .

When two phase conductors are shorted together the only impedance/resistance available to limit the current developed in the established circuit is the very low impedance of the conductors.

Therefore the amount of watts/heat produced by the current flowing in the circuit is only limited by the power available from the voltage source. (Transformer, generator, battery,etc.)

This large amount of energy/watts/heat must be dissipated by the connection and the conductors.

Since the shorted connection is usually the weakest point in the circuit the failure normally occurs at the connection resulting in an arc flash/explosion.

When the conductors are attached to the coil the coil conductors in combination with the pole piece present impedance/resistance to the current flow thereby limiting the amount/magnitude of current produced in the circuit.

The energy produced is converted into magnetic flux allowing the power to be dissipated without causing a failure of any component in the curcuit.

Simplified theory:

E=IR (Ohm's Law)

I=E/R

If E = 440 and R = 1 then I = 440 amps and P = EI = 440 x 440 = 193,600 watts

If E = 440 and R = .5 then I = 880 amps and P = 387,200 watts

If E = 440 and R = 50 then I = 8.8 amps and P = 3,872 watts

If E = 440 and R = 500 then I = .88 amps and P = 387.2 watts

This is a very simplified explanation that in no way takes into account all aspects of AC theory and if you want to understand better it is important that you study/review basic AC theory in depth.