Measurement Of Main Circuit Voltages, Currents And Powers; Insulation Resistance Test Using Megger; Pressure Test; Measurement Of Voltages And Currents - Mitsubishi Electric FR-F700 Series Instruction Manual

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.)
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.
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.
Three
phase
power
supply
Instrument
types
88
R/L1
Power
S/L2
supply
T/L3
500VDC
megger
Input voltage
Input current
Inverter
W11
Ar R/L1
Vr
W12
As S/L2
Vs
W13
At T/L3
Vt
P/+
+
Examples of Measuring Points and Instruments
Motor
U
Inverter
IM
V
W
Ground
U Au
W21
Vu
Av
V
Vv
W Aw
W22
Vw
N/-
V
-
Output voltage
Output current
To the motor
: Moving-iron type
: Electrodynamometer type
: Moving-coil type
: Rectifier type