Why do we need to short M and C in wattmeter?

Originally Answered: Why do we short the M & C terminals during a wattmeter connection? Main and Common terminals are shorted in order to make the “load on the current coil” side configuration or you can say to put the potential coil before current coil.

Which terminals of wattmeter are connected to load?

Wattmeter Internal Circuit The two terminals of the current coil are denoted by M and L. M terminal is to be connected to the power supply and the L terminal is to be connected to the Load. The two terminals of the voltage or pressure coil are denoted by C and V.

What is the difference between UPF and LPF wattmeter?

Answer: LPF wattmeter is used to measure power in inductive circuits. Inductive circuits have the property of lagging power factor and hence these wattmeters are used. So UPF(Unit Power Factor) Wattmeter is used in SHORT CIRCUIT TEST of Transformer.

What is difference between Electrodynamometer and wattmeter?

As nouns the difference between wattmeter and electrodynamometer. is that wattmeter is an instrument for measuring electric power in watts while electrodynamometer is an instrument, having a fixed and a moveable coil, that measures the power flowing in an electric circuit; a type of wattmeter.

When wait Metre C terminal is connected to L terminal in laboratory experiment it means?

‘C’ it is a common terminal is a support device. C,V are two terminal of voltage coil & M,L two terminal of current coil. connect. ‘C’ it is a common terminal is a support device.

What is meant by phantom loading?

Definition: Phantom Loading is a loading condition in which an energy meter is connected to factious or phantom load for testing of energy meter with high current rating. Such loading is favorable to avoid wastage of energy during the test of measurement instrument.

What is M and C in wattmeter?

The current coil of a wattmeter has two terminals Main(M) and Load(L) and Pressure Coil has + or -V and COM(C).

When wattmeter C terminal is connected to a terminal in laboratory experiment it means?

connect. ‘C’ it is a common terminal is a support device. C,V are two terminal of voltage coil & M,L two terminal of current coil. The wattmeter has current coil and pressure coil.

Why LPF wattmeter is used in no load test?

No load losses of transformer, mainly because of magnetising /exciting ampere turns of the core — has low power factor and current is only a few \% of rated current. Hence the use of LPF wattmeter along with matched V&I range.

What are the basic differences between EDM type wattmeter and VAR meter?

The significant difference between the Wattmeter and the energy meter is that the Wattmeter measures the electrical power flows in the circuit, whereas the energy meter measures the total electrical energy consumes by the electrical load.

Why is not an ordinary Electrodynamometer wattmeter suitable for measurement of power in low power factor circuits?

Now there are two main reasons that would suggests us that we should not use ordinary wattmeter in measuring the low value of power factor. The value of deflecting torque is very low even though we fully excite the current and pressure coils. Errors due pressure coil inductance.