Difference Between RYB and UVW

Difference Between RYB and UVW:

Each letter in RYB and UVW mentions each phase of the three phase system. Both says about the phase sequence of the power system. Here R- Red, Y- Yellow color and B means blue color. But incase UVW means just three English letter. Here the RYB notations are often used in transmission lines and Cable manufacturing which means while transferring power from one place to another place we use RYB. At that same time UVW notations are frequently used in Load terminals such as Transformer, motors, generator, etc. To differentiate load terminal to transmission terminal we use these two notations.

Difference Between RYB and UVW
Difference Between RYB and UVW

Example Take an induction Motor terminal. Here you can see that, up to load terminal we use R Y and B. The load terminal of induction motor is called as U, V and W. i.e consider a fault on the cable R phase. If we use all the terminal as one means, we cannot mention the exact fault location either transmission side or load side. Now we can clearly say that Fault occurred on R phase. So the maintenance engineer can easily trace the fault (in our case: he will check only the cable). Unnecessary time and confusion will be avoided.

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Key Points on Difference Between RYB and UVW:

  • RYB mentions in Transmission line and cable. It uses only transmit the power
  • UVW mentions in load side.
  • Purpose of these two is to differentiate load terminal with transmitting terminal.
  • Both are used to mention the phase sequence of the Load


  1. Very good explanation guys, my sons are becoming a electrical engineers n couple years, this will help them understand in the field. thank you


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