please give any idea/concept for wrong AC Phase Sequence detecting

[sahu]

i am trying to detect wrong AC Phase Sequence.
please give any idea/concept for wrong AC Phase Sequence detecting.
those are as ,
if i connect RA0 R PHASE,RA1 B PHASE & RA2 Y PHASE .
if any bode by defolt conecte any phase any port . whats concept for wrong AC Phase Sequence detecting.
.

 

[dick_freebird]

Offhand I'm not sure there is a "wrong" phase (if this
is about an industrial 3-phase motor) - swapping any
two phases is a valid way to reverse the rotation.

Now -in the application- one direction may be right
and one may be very very wrong. But the motor does
not care. And since the motor is often replaced /
wired in at the case, any such sense would have to
be built into the motor and the motor would have to
be "aware of its purpose" (turning a one-size-fits-all
industrial commodity, into two "different" (only in
intent, plus watchdog) model numbers), and now the
selection of the right option becomes the problem
instead - as opposed to requiring a skilled workman
to follow instructions about installation and checkout.
And is it really better to depend on the chain of
specifier, purchaser and less-skilled / diligent
installer plus "widget"? My gut says, not.

Of course if this less a practical / product problem,
and more a thought / homework / neat idea one,
we could go into circuit approaches (although I expect
this is well traveled ground and existing solutions
are out there).

 

[FvM]

Googling "phase sequence detector" or "phase sequence indicator" clarifies there are simple technical solutions, e.g. a RC circuit and a glow discharge lamp.

Related to three phase power supplies (distribution board, power outlet), there's definitely a wrong and right phase sequence.

 

[Circlotron]

Use phase A as a reference.
Measure the time interval from phase B going positive to phase C going positive.
That time interval will be different for forward and reverse rotation.