Hitachi CP-X200 instruction manual General Inverter Electrical Measurements, Pf1

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Troubleshooting and	Troubleshooting and	Maintenance
	Maintenance

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	Reference Value
	measurement	instrument
Supply voltage	ER – across L1 and L2	Moving-coil type			Fundamental	Commercial supply
E1	ES – across L2 and L3	voltmeter or			wave effective	voltage
	ET – across L3 and L1	rectifier type			value	200V class:
		voltmeter				200–240V, 50/60 Hz
						400V class:
						380–460V, 50/60 Hz
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	υ100%			—
factor Pf1		3 υ E1 υ 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		υ100%
		3 υ EO υ IO

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).