Measurement Of Inverter Output Frequency; Insulation Resistance Test Using Megger; Pressure Test - Mitsubishi Electric 800 Series Instruction Manual

7.2.6

Measurement of inverter output frequency

In the initial setting, a pulse train proportional to the output frequency is output across the pulse train output terminals FM and
SD of the inverter. This pulse train output can be counted by a frequency counter, or a meter can be used to read the mean
value of the pulse train output voltage. When a meter 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
7.2.7

Insulation resistance test using megger

• For the inverter, conduct the insulation resistance test on the main circuit only as shown below 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 (high resistance range) and do not use the megger or buzzer.
7.2.8

Pressure test

Do not conduct a pressure test. Deterioration may occur.
Measurement of main circuit voltages, currents and powers
R/L1
Power
Inverter
S/L2
supply
T/L3
500 VDC
megger
PRECAUTIONS FOR MAINTENANCE AND INSPECTION
page 362.
Motor
U
IM
V
W
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