Measurement Of Main Circuit Voltages, Currents And Powers - Mitsubishi Electric FR-D700 Instruction Manual

6.2

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.
When installing meters etc. on the inverter output side
When the inverter-to-motor wiring length is large, especially in the 400V 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.
To measure and display the output voltage and output current of the inverter, it is recommended to use the AM-5 terminal
output function of the inverter.
Three- phase 400V power input
Single-phase 200V power input
Three-phase
power supply
Instrument types
∗ At, As, Vt, Vs, W12, W13 are only for the three-phase power input specification models.
Measurement of main circuit voltages, currents and powers
Input voltage
Input current
Inverter
Ar W11 R/L1 U
Vr
W12 V
As S/L2
∗
∗
Vs
∗
W13
At T/L3 W
∗
∗
Vt
∗
+ -
V
+ -
Examples of Measuring Points and Instruments
Output voltage
Output current
Au
W21
Vu
To the motor
Av
Vv
Aw
W22
Vw
: Moving-iron type
: Electrodynamometer type
: Moving-coil type
: Rectifier type
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