Measurement Of Main Circuit Voltages, Currents And Power - Mitsubishi FR-F500 Instruction Manual

5.3.9 Measurement of main circuit voltages, currents and power

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
3-phase
As
power
supply
At
Instrument
types
Note: Use an FFT to measure the output voltage accurately. Accurate measurement cannot be made if you
use a tester or general measuring instrument.
Input voltage
Input current
Inverter
W R L U
1
11
Vr
W S L V
12 2
Vs
W T L W
13 3
Vt
P + – N
V
+ -
Typical Measuring Points and Instruments
182
PROTECTIVE FUNCTIONS
W
Au
21
Vu
Av To motor
Vv
Aw W
22
Vw
:Moving-iron type
:Electrodynamometer type
:Moving-coil type
:Rectifier type
Output voltage
Output current
5