Measurement Of Main Circuit Voltages, Currents, And Powers - Mitsubishi Electric FR-CS82S-025 Instruction Manual

7.2
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 inverter-to-motor wiring length is long, especially in the 400 V class, small-capacity models, 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.
 Examples of measuring points and instruments
232
7. PRECAUTIONS FOR MAINTENANCE AND INSPECTION

7.2 Measurement of main circuit voltages, currents, and powers

Ar
Vr
Three-phase
As
power supply
Vs
At
Vt
Instrument
types
Input voltage
Input current
Inverter
R/L1 U Au
W11
Vu
Av
W12 S/L2 V
Vv
Aw
W13 T/L3 W
Vw
P/+ N/-
V
+ -
Output voltage
Output current
W21
To the motor
W22
: Moving-iron type
: Electrodynamometer type
: Moving-coil type
: Rectifier type