Three Phase Voltage By Two Wattmeters Method Calculator

Three Phase Voltage

A method used to find the voltage in a three-phase electrical system is called the “Three Phase Voltage By Two Wattmeters Method”. Two wattmeters that are attached to the system are used in this process.
To measure the power in each phase of the system, a wattmeter is linked across two of the three phases. The voltage in the system can be computed using the data from the two wattmeters.

 The “Three Phase Voltage By Two Wattmeters Method” is primarily used to measure the voltage in a three-phase electrical system with accuracy.
This technique offers a dependable way to ascertain the voltage levels across the phases, which is essential to ensure the appropriate functioning of electrical apparatus and systems.
It also aids in locating any voltage imbalances or anomalies in the system, enabling prompt corrections to be made in order to preserve system efficiency and stability.

Understanding Three-phase voltage by Two wattmeter:

Measuring three-phase power with two wattmeters is a widely employed technique for gauging power in a three-phase circuit, often referred to as the two-wattmeter method. Here are the main highlights of this approach:

Principle: The two-wattmeter technique relies on the concept that the overall power usage of a three-phase system can be determined by assessing the power consumption of each phase separately. In this method, two wattmeters are employed to gauge the power in two phases, and the total power consumption is obtained by summing up the measurements from both wattmeters.

Connection: The arrangement of the two wattmeters is tailored for the precise measurement of power across two distinct phases. One wattmeter is linked to gauge power in phases A and B, whereas the second wattmeter is configured to assess power in phases B and C. The wiring setup is as delineated below:

Wattmeter 1: Measure the power in phase A and phase B (VA and VB)

Wattmeter 2: Measure the power in phase B and phase C (VB and VC)


Easy to implement: The two-wattmeter method is a simple and straightforward method to measure three-phase power.

Accurate: The method provides accurate measurements of the total power consumed by the load.

Flexible: The method can be used to measure power in both balanced and unbalanced three-phase circuits.


Requires two wattmeters: The method requires two wattmeters, which can be a limitation in certain applications.

Limited accuracy: The method is sensitive to errors in the measurement of the voltage and current, which can affect the accuracy of the measurement.


  • Industrial Power Systems
  • Utility Monitoring
  • Renewable Energy Systems
  • Electrical Testing and Maintenance

Conclusion: The technique known as the two-wattmeter method is extensively employed to gauge three-phase power. Renowned for its simplicity, precision, and adaptability, it finds widespread application across various industrial settings. Nevertheless, its reliance on two wattmeters and susceptibility to measurement inaccuracies pose challenges, potentially impacting the precision of readings.

To calculate three-phase voltage using the two wattmeter method, use our online calculator. Enter the required data to use the Two Wattmeters Method to calculate the three-phase voltage.

One method that is frequently used to generate, transmit, and distribute alternating current (AC) is three-phase power. It is the principal method for power distribution used by electrical networks throughout the world and is also found in large motors and other appliances with high demand. The Two Wattmeters Method, which involves two alternative load connections—star and delta configurations—can be used to measure three-phase power. This electrical calculator uses the star-type connection to estimate three-phase power.

Note : Don’t end with comma ( , )

Voltage V12
Current I2
Displacement Angle (θ)
Voltage V13
Current I3


\[P=(V_{12}∗I_{2}​ ∗cos(30+θ))+(V_{13} ∗I_{3} ∗cos(30−θ))\]

where :

  • P = Three-Phase Power
  • V12 , V13 = Voltage
  • I2, I3 = Current
  • θ = Displacement Angle
  • cos = Cosine

Any questions? Drop them here!