Ammeter and Voltmeter Connection | Series and Parallel Connection

Ammeter and Voltmeter Connection

The Ammeter is connected in series for the measurement of current and the Voltmeter is connected in parallel for the measurement of voltage.

Today we are going to know the proper connection of Ammeter and Voltmeter. Also, we will discuss Why Ammeter is always connected in series and voltmeter in parallel?

The voltmeter is a measuring device by which we can measure the electrical pressure or potential difference or voltage of an electrical circuit.
The ammeter is a measuring device by which we can measure the amount of flow of current in an electrical circuit.

Why Ammeter is always connected in series?

We always ask that, Why the ammeter is connected in series? but whose series?
Actually, the meaning of that question is that Why ammeter is connected in series with the load?
We know that the current always flows from the source to the load, so if we want to measure the value of current consumed by the load by an ammeter we need to flow that current through the ammeter also. This is possible only when we connect the ammeter between the source and the load in series. 


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When we connect the ammeter between the source and load in series, then the current flow from the source to the load through the ammeter. So the same current will flow through the ammeter as through the load and the ammeter can measure the value of flowing current.

What happened if we connect the ammeter in parallel?

Now you may have a question in your mind that what happened if we connected the ammeter in parallel? If we connected the ammeter in parallel with the load,

1. The current which flows through the load cannot be flowing through the ammeter which is why the ammeter could not measure the value of the current which flows through the load.
2. The connection of the ammeter in parallel with the load means the ammeter is also connected across the source voltage. Now the ammeter acts as a load. As the ammeter has very low resistance a huge amount of current will flow through the ammeter, therefore, the ammeter will be damaged. For this reason, the ammeter should not be connected in parallel without the multiplier.

How to connect the ammeter in parallel?

The ammeter can be connected in parallel with the load for the measurement of the voltage across the load. An external high-value resistance which is also called a multiplier is to be connected in series with the ammeter and then the ammeter can be connected in parallel with the load for voltage measurement.

Why voltmeter is always connected in parallel?

If we apply any voltage across the voltmeter then the voltmeter measures the applied voltage across it and shows the value to us. So if we want to measure the voltage across the load in an electrical circuit, then the same voltage is to be applied across the voltmeter as the voltage across the load. This is possible only when we connect the voltmeter in parallel with the load.

When we connect the voltmeter in parallel with the load, then the same voltage will occur across the voltmeter as the voltage across the load. Therefore the voltmeter measures the voltage and shows the value to us.

What happened if we connect the voltmeter in series?

1. When we connect the voltmeter in series with the load no voltage will occur across the voltmeter, therefore, the voltmeter could not measure the voltage.
2. The voltmeter has very high resistance so when we connect the voltmeter in series, then the internal resistance of the voltmeter will oppose the flow of current hence no current will flow from source to load.

How to connect the voltmeter in series?

The voltmeter can be connected in series with the load for measurement of current. An external low-value resistance which is also called Shunt is to be connected in parallel with the voltmeter and then the voltmeter can be connected in series with the load for current measurement.

Also, remember that Voltmeter and ammeter both can be connected in the same circuit to measure the electrical power. Once the ammeter and voltmeter are connected you can turn on the power to the circuit and read the current (I) value on the ammeter and the voltage (V) value on the voltmeter. Calculate the power using the formula P = VI. The unit of power will depend on the units of current and voltage used (e.g., watts, kilowatts). Remember that this will work in the DC power system only. As the AC power system has a power factor so you can get the apparent power only by using this formula. To get the real power you need to put the power factors also.


Read Also:

• All-in-one Voltage Current Frequency Meter Connection Diagram
• Analog and Digital Frequency Meter Connection Diagrams
• Three(3) Phase Digital Panel kWh Meter Connection Diagram
• Ammeter Connection Diagram with Selector Switch and CT
• Voltmeter and Selector Switch Connection for Three (3) Phase Supply
• Digital Voltmeter Wiring Diagram and Connection Procedure

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