Mitsubishi Electronics FR-V500 Measurement of main circuit voltages, currents and powers

Precautions for maintenance and inspection

6.5.8Inverter replacement

The inverter can be replaced with the control circuit wiring kept connected. Before replacement, remove the screws in the wiring cover of the inverter.

1)Remove the mounting screws in both ends of the control circuit terminal block.

2)With both hands, pull down the terminal block from behind the control circuit terminals.

3)When installing the terminal block to a new inverter, exercise care not to bend the pins of the control circuit ter- minal block connector.

CAUTION

Before starting inverter replacement, switch power off, wait for more than 10 minutes, and then check the voltage with a tester and such to ensure safety.

6.5.9Measurement of main circuit voltages, currents and powers

!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.

3-phase 200V power input

Input voltage	Output voltage
Input current	Output current

	Ar	W11
3-phase		Vr
power	As	W12
supply		Vs
	At	W13
		Vt

Inverter

R U Au W21 Vu

S V Av

Vv

T W Aw W22

Vw

PN

V

To motor

: Moving-iron type

: Electrodynamometer type

Instrument types

+	-
	: Moving-coil type

: Rectifier type

Examples of Measuring Points and Instruments

CAUTION

Use an FFT to measure the output voltage accurately.

A tester or general measuring instrument cannot measure accurately.

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