Mitsubishi Electronics FR-A500L Measurement of main circuit voltages, currents and power

PROTECTIVE FUNCTIONS

5.3.7 Measurement of main circuit voltages, currents and power

●Measurement of voltages and currents

Since the voltages and currents on the inverter power supply and output sides include harmonics, accurate measurement depends on the instruments used and circuits measured.

When instruments for commercial frequency are used for measurement, measure the following circuits using the instruments given on the next page.

Input voltage

Input current

Output voltage

Output current

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

Instrument types

Inverter
R<L1>	U	Au	Vu	W12
S<L2>	V	Av	Vv
T<L3>	W	Aw	Vw	W22
P<+> <->N
2	5

V

+-

To motor

Typical Measuring Points and Instruments

Note: Use an FFT to measure the output voltage accurately. Accurate measurement cannot be made if you use a tester or general measuring instruments.

39