Hitachi X200 Series instruction manual General Inverter Electrical Measurements, Pf1 =

6−12

General Inverter Electrical Measurements

The following table specifies how to measure key system electrical parameters. The diagrams on the next page show inverter-motor systems and the location of measurement points for these parameters.

Parameter	Circuit location of		Measuring			Notes
		measurement	instrument
Supply voltage	ER – across L1 and L2		Moving-coil type			Fundamental
E1	ES – across L2 and L3		voltmeter or			wave effective
	ET – across L3 and L1		rectifier type			value
			voltmeter
Supply current	Ir – L1					Total effective
I1	Is – L2					value
	It – L3
Supply power	W11	– across L1 and L2				Total effective
W1	W12	– across L2 and L3				value
Supply power		Pf1 =	W1	⋅100%
factor Pf1
			3 ⋅ E1 ⋅ I1
Output voltage	EU – across U and V		Rectifier type			Total effective
EO	EV – across V and W		voltmeter			value
	EW – across W and U
Output current	IU – U		Moving-coil type			Total effective
IO	IV – V		ammeter			value
	IW – W
Output power	WO1	– across U and V	Electronic type			Total effective
WO	WO2	– across V and W	wattmeter			value
Output power	Calculate the output power factor from the output voltage E,
factor PfO	output current I, and output power W.
		PfO =	W1		⋅100%
			3 ⋅ EO ⋅ IO

Reference Value

Commercial supply voltage

200V class: 200–240V, 50/60 Hz

400V class: 380–460V, 50/60 Hz

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Troubleshooting and Maintenance

Note 1: Use a meter indicating a fundamental wave effective value for voltage, and meters indicating total effective values for current and power.

Note 2: The inverter output has a distorted waveform, and low frequencies may cause erroneous readings. However, the measuring instruments and methods listed above provide comparably accurate results.

Note 3: A general-purpose digital volt meter (DVM) is not usually suitable to measure a distorted waveform (not pure sinusoid).