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Re: 3-phase reactor
Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx>
Hi,
Any small inductance meter driven by say a 9V battery will not be
able to pump enough current through a big iron core to get past the
hysteresis curves.
http://www.lassp.cornell.edu/sethna/hysteresis/WhatIsHysteresis.html
It's like trying to push a bus with a feather. So the reading will
be very high until you get enough current to get the iron working.
Typically you need to get out a variac, loads, scopes and such to
measure it the direct basic way. There are some high current AC
meters out there, but they are usually "special". Everyone really
just sets it up on the bench with scopes and all...
Once you get a known AC current though the winding, you can measure
the voltage across the winding and the inductance is:
L = V / (I x 2 x pi x 60)
You can even measure the inductance for various currents and make a
graph of when the core kicks in (low current) and when it saturates
(high current).
3 phase is a bit odd since they use the other phases to "fight" each
other and keep core magnetization down avoiding early
saturation. Just one phase will probably saturate sooner than
expected if I am thinking right on that.
Of course, in your case, you are lucky and it is already labeled ;-))
Cheers,
Terry
At 10:03 PM 7/11/2006, you wrote:
Hi All,
I recently came across a reactor in a junk bin with three separate
coils wound on the same core. It is marked:
AC253V 24A 0.15mH 3ph.
When checking it with my AADE LCII meter, each section measures 1.50
mH. - ten times the rated value. I was hoping to use this as a
ballast but I have no idea what value to expect. Any reactor guru
want to take a shot at enlightenment.
Matt D.