Fuji Electric FVR-C11S-7EN Series - Electrical Measurements in the Main Circuit

8-5 8 Maintenance and Inspection
FVR-C11S-EN
8
Table 8-3-1 Meter for measurin
g
the main circuit
1) When measurin
g
the output volta
g
e b
y
rectifier t
y
pe meter, an error ma
y
occur.
Use a di
g
ital AC power meter for
g
ood accurac
y
.
8-3 Electrical
measure-
ments in the
Main Circuit
The indicated values depend on the meter t
y
pes because of harmonic
components included in the volta
g
e and current of the main power sup-
pl
y
(input) and the output (motor) side of the inverter. Therefore, when
measurin
g
with a meter for the commercial power frequenc
y
, use the
meters shown in Table 8-3-1.
The power-factor cannot be measured usin
g
the power-factor meter
available on the market which measures the phase difference between
volta
g
e and current. When the power-factor must be measured, meas-
ure the power, volta
g
e, and current on the input side and output side.
Then, calculate the power-factor usin
g
the followin
g
formulas:
Sin
g
le-phase
Electric power [W]
Power factor = x 100 [%]
Volta
g
e [V] x Current [A]
Item
Input (power suppl
y
) side Output (motor) side DC circuit
Volta
g
e
waveform
Current
waveform
Volta
g
e
waveform
Current
waveform
P(+), N(-)
FM, 11
Terminal
section
Meter
name
Ammeter
A
R
Voltmeter
V
R
Wattmeter
W
R
Ammeter
A
U,V,W
Voltmeter
V
U,V,W
Wattmeter
W
U,W
DC
voltmeter
V
Meter
t
y
pe
Movin
g
-
iron t
y
pe
Rectifier
or
movin
g
-
iron t
y
pe
Power
meter
Movin
g
-
iron t
y
pe
Rectifier
t
y
pe
1
)
Power
meter
Movin
g
-
coil t
y
pe
S
y
mbol - -