General Inverter Electrical Measurements - Hitachi X200-002SFE/NFU Instruction Manuals

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
Supply voltage
E
Supply current
I
1
Supply power
W
Supply power
factor Pf
Output voltage
E
Output current
I
O
Output power
W
Output power
factor Pf
Note 1:
Note 2:
Note 3:
More user manuals on
Circuit location of
measurement
E – across L1 and L2
R
E – across L2 and L3
1 S
E – across L3 and L1
T
I – L1
r
I – L2
s
I – L3
t
W – across L1 and L2
11
W – across L2 and L3
1 12
Pf
1
E – across U and V
U
E – across V and W
O V
E – across W and U
W
I – U
U
I – V
V
I – W
W
W – across U and V
O1
W – across V and W
O O2
Calculate the output power factor from the output voltage E,
output current I, and output power W.
O
Pf
Use a meter indicating a fundamental wave effective value for voltage, and meters
indicating total effective values for current and power.
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.
A general-purpose digital volt meter (DVM) is not usually suitable to measure a
distorted waveform (not pure sinusoid).
ManualsBase.com
Measuring
instrument
Moving-coil type
voltmeter or
rectifier type
voltmeter
W
= ×
1
100 %
1 × ×
3 E I
1 1
Rectifier type
voltmeter
Moving-coil type
ammeter
Electronic type
wattmeter
W
= ×
1
100 %
O
× ×
3 E I
O O
Notes Reference Value
Fundamental Commercial supply
wave effective voltage
value 200V class:
200–240V, 50/60 Hz
400V class:
380–460V, 50/60 Hz
Total effective —
value
Total effective —
value
—
Total effective —
value
Total effective —
value
Total effective —
value
—