Phase Rotation

24 Nov 2011

Hi, i'm thinking of making a phase rotation analyzer to directly measure the rotation on 3-phase 220VAC(420VAC), does anyone know if it's possible, and if it it's, how it can be done?? Thanks

04 Dec 2011

to Renato Loureiro..

I am uncertain of the term 'rotation' for 3-phase AC sources- can you elaborate? I suspect that you might be wanting to measure PHASE ANGLE between each of the branches. Tools (generally pricey) are available to measure such, particularly used in scenarios where reactive loads may be causing uneven energy consumption. Imbalanced branches that can cause phase shifts within source transformer causing heating effects that can lead to big problems. Generally, the angle of each 3PH branch is 120 degrees from the other branches that 'lead' by or 'lag' by 120 degees; the sum of the angles will always equal 360 degrees, and the frequency of each each branch will be identical. Amplitudes will vary due losses such as contact resistance, copper losses, transformer variations, loading variations, AND GENERALLY phase variations. Where phase varies, transient or harmonic distortions will also appear.

I am not an expert at this, but I suspect you might search about and find various methods for deriving measurable HVAC properties, but considerable SAFETY EFFORT IS NECESSARY before one begins constructing such a project: evaluate carefully!!! IF you are skilled with experience in HVAC you are prepared more than myself (I prefer micropower projects). The MBED has capacity to easily resolve parameters related to HVAC such as Voltage, Current, Frequency, Phase, Harmonic Distortion, Power Factor, and Logging Realtime characteristics, and flagging data extremes, limits, transient events, streaming loads, whatever; the sky is the limit!

I hope you are not re-inventing 'the wheel' as such products are already available. Have SAFE fun with Mbed - KC