Megger INGVAR, Руководство пользователя

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50 ZP-BH05E BH0654BE
8 APPLICATION EXAMPLES
Note
Another method to measure the ratio be-
tween primary and secondary current is to
set the unit for ammeter 1 to "I1/I2". Do not
however try to combine the two methods!
8.3 Measuring the polarity
of a current transformer
You can conduct a polarity test to determine whether
or not the current direction in a current transformer is
correct.
In this test it is to be verified that the terminal S1 (X1)
on the secondary side is positive relative to terminal
S2 (X2) when terminal P1 (H1) on the primary side is
positive relative to terminal P2 (H2).
1]
Basic setting:
OPERATE OFF
2]
Connect the one of the output terminals on
INGVAR’s which is marked with a dot (·) to P2
(H2) on the primary side of the CT.
3]
Connect the other output terminal to P1
(H1).
4]
Connect the one of A-METER 2:s A termi-
nals which is marked with a dot (·) to S2 (X2)
on the secondary side of the CT.
5]
Connect the other terminal of A-METER 2 A
to S1 (X1).
6]
Activate INGVAR’s second ammeter
(A-METER 2) A under the "A-METER 2"
menu heading in the "V/A METER" menu
option.
7]
Press the ESC button (normally twice) until
the sign for degrees (" ° ") appears in the
upper-left corner of the display.
8]
Press
TIME
.
9]
Turn the current up until the a stable phase-
angle appears on the display.
10]
If the phase angle is close to 0° or 359° the
polarity is correct. If the phase angle is 180°,
the polarity is incorrect.
11]
Press OFF .
12]
Move the cables used for A-METER 2 A to
the other secondary windings and check
them in the same way.
A sample hookup is shown in fig 8.1.