88
Measurement of main circuit voltages,
currents and powers
6.2 Measurement of main circuit voltages, currents and powers
6.2.1
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 500VDC megger.)
6.2.2
Pressure test
Do not conduct a pressure test. Deterioration may occur.
6.2.3
Measurement of voltages and currents
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.
Examples of Measuring Points and Instruments
CAUTION
• 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.
U
V
W
Inverter
500VDC
megger
Power
supply
IM
Motor
R/L1
S/L2
T/L3
Ground
+
-
Ar
As
At
Vr
Vs
Vt
W11
W12
W13
Au
Av
Aw
Vu
Vv
Vw
W21
W22
V
U
V
W
Inverter
Three
phase
power
supply
To the motor
Instrument
types
Input voltage
Input current
Output voltage
Output current
: Moving-iron type
: Electrodynamometer type
: Moving-coil type
: Rectifier type
R/L1
S/L2
T/L3
P/+
N/-
Summary of Contents for FR-F700 Series
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