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Phase detection circuit, R, S, T changes

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Junior Member level 2
Jan 12, 2011
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Dear all

S 120 degrees from phase to phase, we are ahead of R and T phase to 240 degrees ahead of the R phase is please help Me.That the circute phase to determine which of R, which is T or s ?

Your question is not clear. You have a reference vector which R, S &T could be related to. Draw a big cross, label from the centre upwards " reference ", now going clockwise count of the degrees and label the vectors. I am sure that the answer will come to you.

My question is, how it can be diagnosed in a three-phase cable carrying electricity S or R or T phase, which is in a phase I want the cursor

I can hardly understand what you are asking for, but if I understood correctly, you need a circuit to detect which phase is which, R, S or T right?

But there is no such thing as R, S, T. Name them A, B, C or L1, L2, L3 if you like. The fact is that there are three phases with 120 degrees phase difference with each other. Each phase has another phase leading 120 degrees ahead, and a phase following 120 degrees behind.

So if for example a machine asks for R, S, T inputs, you simple place the three phases to those inputs randomly, without worrying about which phase goes where.

Three-phase - Wikipedia, the free encyclopedia
Three-phase electric power - Wikipedia, the free encyclopedia

Thank you all

---------- Post added at 11:21 ---------- Previous post was at 11:00 ----------

OK L1,L2,L3 PHASE . but I want measure each phase to neutral and Identify the type and phase

---------- Post added at 13:13 ---------- Previous post was at 11:21 ----------

please help me thanks

You can identify the relation of the 3 phases, but not a "type", because you don't know which one is R, S, or T. These are arbitrary assignments, only meaningful if you have a second connector or cable that's connected to the same grid.

Different phases L1, L2, L3 in the 120 ° phase difference. By a phase sensing circuit of the type to be null phase.

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