8-4
Maintenance and Inspection
8
8-3
Measurement of Current and
Voltage in Main Circuit
Because the voltage and current of the power
supply (input) of the main circuit of the inverter
and the output (motor) include harmonic
components, the indicated value varies
according to the type of the meter. Use meters
indicated in Table 8-3-1 when measuring with
meters for commercial frequencies.
Marketed power factor meters measuring phase
difference between the voltage and current
cannot measure the power factor. To obtain the
power factor, measure the power, voltage and
In case of Single-phase
Table 8-3-1 Meters for measurement of main circuit
Fig 8-3-1 Connection of measuring instruments
In case of Three-phase
Input (power supply) side
Output (motor) side
Link voltage
(P(+)-N(-))
Voltage
Current
Voltage
Current
Ammeter
Voltmeter
Wattmeter
Ammeter
Voltmeter
Wattmeter
DC voltmeter
A
R
,
S
,
T
V
R
,
S
,
T
W
R
,
S
,
T
A
U
,
V
,
W
V
U
,
V
,
W
W
U
,
V
,
W
V
Moving iron
Rectifier or
Digital
Moving iron
Rectifier
Digital
Moving coil
type
moving iron
power
type
type
power
type
type
meter
meter
current on each of the input and output sides
and calculate in the following formula.
Item
Name of
meter
T
ype of
meter
Symbol of
meter
Note)
When the output voltage is measured by a
rectifier type, an error may be included. To increase
the accuracy, use a digital AC power meter.
A
U
A
V
A
W
W
U
W
W
V
U
V
V
V
W
A
W
V
Power
Supply
L1/L
L2/N
V
+
-
P(+)
N(-)
U
V
W
M
Motor
VXSM***-1
VXSM***-3
A
U
A
V
A
W
W
U
W
W
V
U
V
V
V
W
A
R
A
S
A
T
W
R
W
T
V
R
V
S
V
T
Power
Supply
L1/R
L3/T
L2/S
V
+
-
P(+)
N(-)
U
V
W
M
Motor
Содержание VXSM150-1
Страница 3: ......
Страница 41: ...5 12 Selecting Functions 5 Frequency setting block diagram ...
Страница 45: ...5 16 Selecting Functions 5 Note The chain line indicates the motor speed ...
Страница 71: ...7 1 Troubleshooting 7 7 Troubleshooting 7 1 When Protective Function Activates 1 Overcurrent ...
Страница 72: ...Troubleshooting 7 2 7 2 Overvoltage 3 Undervoltage ...
Страница 77: ...7 7 Troubleshooting 7 3 The motor loses speed during acceleration 4 Excessive heat generation from motor ...