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3 phase 3 wire voltage meaurement

3-phase
energy
acvoltage
Tags: #<Tag:0x00007f1feaaf3960> #<Tag:0x00007f1feaaf3708> #<Tag:0x00007f1feaaf34b0>

(ajit) #1

Dear all,

I am trying to build 3 phase voltmeter that could measure L-L and L-N voltage during 3 phase 3 wire and 3 phase 4 wire connection. 3 phase 3 wire and 3 phase 4 wire connection are external connection.

as we know in 3 phase 4 wire we will get neutral reference so we can get accurate reading for L-L and L-N.
but in case of 3 phase 3 wire we dont have neutral reference .In this case it will be difficult to get gnd reference. I would like use both connection type in common circuit,

I have seen one of the product where they using V-X-M-H IC , can some one suggest me functionality of this iC. i have attached schematic for reference.

If any other suggestion with schematic will be appreciated. to differentiate 3 phase 3 wire and 3 phase 4 wire


i would like to know what V-X-M-H ic will do here.

Is there any recommended circuit to read 3 phase 3 wire voltage. how i can use ground reference.


(Robert Wall) #2

In general, there need not be any ground reference at all in a 3-wire, 3-phase system. You can measure with respect to any voltage you care to name, so by measuring two line voltages with respect to some third voltage, and their relative phase, you can do the mathematics on the resulting phasors to obtain the the line - line voltage.

I cannot find what “VXMH” is, so until someone can say, nobody can help you.


(ajit) #3

Is there sample code or circuit available. My intention use common circuit. Where I could I use phase and neutral for 3 phase 4 wire and 3 phase 3 wire.

In above circuit its doing it. There some if like ad7755 device but there also not mention how it connected to 3 phase 3 wire system