N700E INSTRUCTION MANUAL
8.3
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 the location of measurement points
for these parameters.
Parameter
Supply voltage
E
1
Supply current
I
1
Supply power
W
1
Supply power
factor
P
f1
Output voltage
E
0
Output current
I
0
Output power
W
0
Output power
factor
P
f0
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 PWM 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 PWM waveform
(not pure sinusoid)
Circuit location
of measurement
R-S, S-T, T-R
(E
) (E
) (R
)
R
S
T
R, S, T, Current
(I
) (I
) (I
)
R
S
T
R-S, S-T
(W
) + (W
)
11
12
Calculate the output power factor from the output voltage E
output current I
, and output power W
1
U-V, V-W, W-U
(E
) (E
) (E
)
U
V
W
U, V, W
Current
(I
) (I
) (I
)
U
V
W
U-V, V-W
(W
) + (W
)
01
02
Calculate the output power factor from the output voltage E
output current I
, and output power W
0
Measuring instrument
Moving-coil type
voltmeter or rectifier
type voltmeter
Moving-coil type
Ammeter
Electronic type
wattmeter
1
Rectifier type voltmeter
Moving-coil type
Ammeter
Electronic type
wattmeter
0
8-4
Reference
Notes
Value
Commercial
Fundamental
supply voltage
wave effective
(200V class)
value
200-220V 50Hz
200-240V 60Hz
(400Vclass)
Total effective
380-415V 50Hz
value
400-480V 60Hz
Total effective
value
,
1
Total effective
value
Total effective
value
Total effective
value
,
0