Meters And Measuring Methods - Mitsubishi Electric FR-E700 Instruction Manual

Meters and measuring methods

7.7 Meters and measuring methods
NOTE For further information about measurements at the inverter refer to section 8.2.
Since voltages and currents in the primary and secondary side of the inverter include harmonics, dif-
ferent meters indicate different measured values.
When installing meters etc. on the inverter output side
When the inverter-to-motor wiring length is large, especially in the 400 V class, large-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.
When measuring and indicating the output voltage and output current of the inverter, it is recom-
mended to utilize the AM-5 terminal output function of the inverter.
When using measuring instruments for the normal frequency range, carry out the measurements as
described below.
power supply
Instrument types
Fig. 7-7:
7 - 30
Input voltage
Input current
3-phase
Measurements at the main circuit
Inverter
Troubleshooting
Output voltage
Output current
To the motor
Moving-iron type
Electro dynamometer type
Moving-coil type
Rectifier type
I001313E