Measurement Of Inverter Output Frequency - Mitsubishi Electric 800 Series Instruction Manual

When energy is regenerated from the motor during deceleration, for example, the converter output voltage rises to nearly 400
to 450 V for the 200 V class, nearly 800 to 900 V for the 400 V class, and nearly 1100 to 1300 V for the 575 V class maximum.
3.2.7

Measurement of inverter output frequency

In the initial setting of the FM type inverter, a pulse train proportional to the output frequency is output across the pulse train
output terminals FM and SD on the inverter. This pulse train output can be counted by a frequency counter, or a digital
multimeter can be used to read the mean value of the pulse train output voltage. When a digital multimeter is used to measure
the output frequency, approximately 5 VDC is indicated at the maximum frequency.
For detailed specifications of the pulse train output terminal FM, refer to the FR-E800 Instruction Manual (Function).
3.2.8 Insulation resistance test using megger
• For the inverter, conduct the insulation resistance test on the main circuit only as follows and do not perform the test on
the control circuit.
(Use a 500 VDC megger.)
NOTE
• Before performing the insulation resistance test on the external circuit, disconnect the cables from all terminals of the inverter
so that the test voltage is not applied to the inverter.
• For the continuity test of the control circuit, use a tester for high resistance range and do not use the megger or buzzer.
Power
supply
500 VDC
megger
3.2.9 Withstand voltage test
Do not conduct a withstand voltage test. Deterioration may occur.
Motor
R/L1 U
Inverter
IM
S/L2 V
T/L3
W
3. Precautions for Maintenance and Inspection
3.2 Measurement of main circuit voltages, currents, and powers
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