Instruction manual

Table Of Contents
PROTECTIVE FUNCTIONS
162
5.3.8 Measurement of main circuit voltages, currents and powers
!
!!
!
Measurement of voltages and currents
Since the voltages and currents on the inverter power supply and output sides include
harmonics, accurate measurement depends on the instruments used and circuits
measured.
When instruments for commercial frequency are used for measurement, measure the
following circuits using the instruments given on the next page.
Ar
As
At
Vr
Vs
Vt
W11
W12
W13
Au
Av
Aw
Vu
Vv
Vw
W12
W22
V
R
(L
1
)
S
(L
2
)
T
(L
3
)
U
V
W
P
N
Output
voltage
(Note)
Three-phase 200V power input
Input
voltage
Input
currents
Output
currents
Inverter
3-phase
power
To motor
Instrument types
(
+
)(
)
+
Typical Measuring Points and Instruments
Note: Use FFT
(
Fast Fourier Transforms
)
to measure the out
p
ut volta
g
e
accurately.
It cannot be measured accurately with a meter or general instrument.