Table of Contents
How many coils are there in a watt meter?
An electrical instrument used to measure electric power in watts of any circuit is called Wattmeter. It consists of two coils like the current coil and voltage coil. The current coil, which is connected in series & voltage coil is connected in parallel.
What is a pressure coil?
A pressure coil is also known as the voltage coil and is generally used in a wattmeter. Moreover, the current coil measures the current while the pressure coil measures the voltage. Both the coils are used in a wattmeter scale and to measure current or voltage in tension transmission lines.
Why pressure coil of energy meter is highly inductive?
This coil is known as “pressure or voltage” coil and is connected across the supply mains. This voltage coil has many turns and is arranged to be as highly inductive as possible. In other words, the voltage coil produces a high ratio of inductance to resistance.
How many current coils are there in power factor meter?
General construction of any power factor meter circuit include two coils namely pressure coil and current coil. Pressure coil is connected across the circuit while current coil is connected such that it can carry circuit current or a definite fraction of current.
How does a watt meter work?
A wattmeter does a complex job, measuring the power flowing through an electrical circuit. It simultaneously measures the voltage and current values and multiplies them to give power in watts. The three main types are electrodynamic, electronic and digital.
What is meant by current coil?
Definition of Current Coil. A current coil is basically a coil, such as, a wire wrapped around an electrical conductor. Usually, the coil is made out of insulated copper wire and the conductor is a soft iron core. This property of a conductor, when wrapped around a current-carrying coil, is called electromagnetism.
Why current coil is always connected in series?
The flow of current is always along the length of the conductor. The purpose of using ammeter is to measure the rate of current flowing through it. Hence, to make the measurement possible, the whole current has to flow through the coil of the ammeter. This is why ammeter is connected in series.
What are current coils and pressure coils in an energy meter?
Both the coils you have mentioned are important parts of an energy meter or a watt meter. The current coil is connected in series with the load and the pressure coil is connected in parallel with the load. Current is measured by the current coil and voltage is measured by the pressure coil.
Can a pressure coil be connected to a wattmeter?
The common terminal of the pressure coil may be connected after or before the current coil. Based on this connection, there are two methods of wattmeter connections. Each method is suitable for one particular case. These two methods of wattmeter connection is explained below;
What is the flux of a wattmeter coil?
The wattmeter incorporates two coils namely pressure coil (PC) and current coil (CC) that carry voltage and current of the circuit respectively. The pressure coil produces a flux Φ proportional to the voltage (V).
What is the voltage of a pressure coil?
The terminals of the pressure coil are marked as ± and V. In some meters it is marked as COM and V. The first one is the common terminal and the second one is the specified voltage terminal with actual voltage marking as 115V, 230V or 440V.