21
III.5 Measurement of a System with CT or VT
PO
W
ER
(H
AR
MO
N
)
10A
1A
(H
AR
MO
N
)
100A
10
0A
(P
O
W
ER
)
60A
3 4W+PT+CT
X
Y-Y
連接
PT 3
CT3
CT2
CT1
I
3
2
I
I
1
V
3N
2N
V
V
1N
+
+
+
+
+
+
60A
(P
O
W
ER
)
10
0A
100A
(H
AR
M
O
N)
1A
10A
(H
AR
M
O
N)
(HARM
O
N)
10
A
1A
(HARM
O
N)
100A
100A
(P
O
W
E
R)
60
A
a. Turn the power on. Press the POWER and the 1
Φ
3
Φ
buttons to select
the 3P4W system. The type of system will be displayed at the bottom
right of the LCD.
b. Connect the four test leads to the secondary voltage terminals L1, L2, L3
and the V
N
(Neutral) of the system.
c. Clamp on to the secondary coils of L1, L2, and L3. Make sure the
current flows from the front of the current probe to the back of it.
d. Press the SETUP button and the CT symbol will be shown in reverse
video in LCD.
e. Press
the
▲
or
▼
buttons to increment or decrement the RATIO
specified by the CT.