Measurement Of Main Circuit Voltages, Currents And Power - Mitsubishi Electric FR-A500L Series Instruction Manual

5.3.7 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.
3-phase
power
supply
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 instruments.
Input voltage
Input current
W R<L
Ar
11
Vr
W
S<L
As
12
Vs
W
T<L
At
13
Vt
P<+>
2
Typical Measuring Points and Instruments
PROTECTIVE FUNCTIONS
Inverter
> U
Au
1
Vu
> V
Av
2
Vv
> W
Aw
3
Vw
<->N
5
V
+ -
39
W
12
To motor
W
22
Output voltage
Output current