Rockwell Automation 7000A PowerFlex Medium Voltage AC Drive (A Frame) - ForGe Control (PanelView 550) User Manual
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Component Definition and Maintenance
7000A-UM151D-EN-P – March 2013
7000 “A” Frame
e.g. - the capacitor under test is rated at 400 kVAR, 6600V, 50Hz, 29.2
µF.
You are using 200V, 50Hz test power and have recorded the values of
voltage and current for each test as given in the table below.
Phase - Neutral
L1-N L2-N
L3-N
Test Voltage
200V
200V
200V
Measured Current
1.87A
1.866A
1.861A
Let us calculate the capacitance using the first reading. In this case:
V = 200V, I = 1.87 for L1-N
Xc = V/I = 200/1.87 = 106.95
F
C
C
Xc
f
C
μ
π
7
.
29
95
.
106
50
14
.
3
2
1
2
1
=
Ч
Ч
Ч
=
=
Where,
f = frequency of the applied voltage.
Similarly, you can calculate the capacitance for the remaining two
measurements for L2-N and L3-N.
D.C. Link / Fan / Control
Components (cont.)