Measurement Of Main Circuit Voltages, Currents And Powers - Mitsubishi Electric F800-E Series Instruction Manual

Measurement of main circuit voltages, currents and powers

5.2
Measurement of main circuit voltages,
currents and powers
Since the voltages and currents on the inverter power supply and output sides include harmonics, measurement data
depends on the instruments used and circuits measured.
When instruments for commercial frequency are used for measurement, measure the following circuits with the instruments
given on the next page.
NOTE
• When installing meters etc. on the inverter output side
When the wiring length between the inverter and the motor is large, the meters and CTs may generate heat due to line-to-line
leakage current. Therefore, choose the equipment which has enough allowance for the current rating.
To measure and display the output voltage and output current of the inverter, it is recommended to use the terminal AM and
CA output functions of the inverter.
Examples of measuring points and instruments
Three-phase
power supply
Instrument
types
70
PRECAUTIONS FOR MAINTENANCE AND INSPECTION
Input voltage
Input current
Inverter/
converter unit
Ar R/L1
W11
Vr
As W12 S/L2
Vs
At
W13 T/L3
Vt
P/+
V
+
U Au
W21
Vu
Av
V
Vv
Aw
W
W22
Vw
N/-
-
Output voltage
Output current
To the motor
: Moving-iron type
: Electrodynamometer type
: Moving-coil type
: Rectifier type