Measurement Of Inverter Output Frequency; Insulation Resistance Test Using Megger; Pressure Test - Mitsubishi Electric FR-A800 Instruction Manual

Measurement of main circuit voltages, currents and powers
5.2.7

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 of the inverter. This pulse train output can be counted by a frequency counter, or a meter
(moving-coil type voltmeter) 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 the FR-A800 Instruction Manual (Detailed).
In the initial setting of the CA-type inverter, a pulse train proportional to the output frequency is output across the analog
current output terminals CA and 5 of the inverter. Measure the current using an ammeter or tester.
For detailed specifications of the analog current output terminal CA, refer to the FR-A800 Instruction Manual (Detailed).
5.2.8

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.
5.2.9

Pressure test

Do not conduct a pressure test. Deterioration may occur.
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PRECAUTIONS FOR MAINTENANCE AND INSPECTION
R/L1
Power
Inverter
S/L2
supply
T/L3
500VDC
megger
Motor
U
IM
V
W