Measuring Points and Instruments
Item
Measuring Point
R/L1 and S/L2
Power supply voltage
S/L2 and T/L3
V
1
T/L3 and R/L1
Power supply side
R/L1, S/L2, T/L3 line
current
current
I
1
R/L1, S/L2, T/L3 and
Power supply side
R/L1 and S/L2,
power
S/L2 and T/L3,
P
1
T/L3 and R/L1
Calculate after measuring power supply voltage, power
supply side current and power supply side power.
Power supply side
power factor
Pf
1
Pf
1
Output side voltage
Across U and V, V and W,
V
and W and U
2
Output side current
U, V and W line currents
I
2
Output side power
U, V, W and
P
2
U and V, V and W
Calculate in similar manner to power supply side power factor.
Output side power
Pf
factor
2
Pf
2
Converter output
Across P/+ and N/-
Frequency setting
Across 2(+) and 5
signal
Across 4(+) and 5
Frequency setting
Across 10(+) and 5
power supply
Frequency meter
Across FM(+) and SD
signal
Start signal
Across SD and STF, STR,
Select signal
RH, RM, or AU(+)
Across A and C
Fault signal
Across B and C
Use an FFT to measure the output voltage accurately. An FA tester or general measuring instrument cannot measure accurately.
When the carrier frequency exceeds 5kHz, do not use this instrument since using it may increase eddy-current losses produced in metal parts inside the
instrument, leading to burnout. In this case, use an approximate-effective value type.
When the setting of Pr. 192 A,B,C terminal function selection is positive logic
A digital power meter (designed for inverter) can also be used to measure.
Measurement of main circuit voltages, currents and powers
Measuring Instrument
Moving-iron type AC
voltmeter
Moving-iron type AC
ammeter
Digital power meter
(designed for inverter) or
electrodynamic type single-
phase wattmeter
P
1
%
=
----------------------- -
100
3V
I
1
1
Rectifier type AC voltage
meter
(moving-iron type cannot
measure)
Moving-iron type AC
ammeter
Digital power meter
(designed for inverter) or
electrodynamic type single-
phase wattmeter
P
2
=
----------------------- -
100
%
3V
I
2
2
Moving-coil type
(such as tester)
Moving-coil type
(tester and such may be
(internal resistance 50k or
Moving-coil type
(such as tester)
Remarks (Reference Measured Value)
Commercial power supply
Within permissible AC voltage fluctuation (Refer to
page 330)
P
=W
+W
1
11
12
Difference between the phases is within 1% of the
maximum output voltage.
Difference between the phases is 10% or lower of
the rated inverter current.
P
W
2 =
21 +
2-wattmeter method (or 3-wattmeter method)
Inverter LED display is lit. 1.35 × V1
0 to 10VDC, 4 to 20mADC
5.2VDC
Approximately 5VDC at maximum
frequency
(without frequency meter)
used)
8VDC
more)
Pulse width T1 : Adjust with C0 (Pr.
900)
Pulse cycle T2 : Set with Pr. 55
(frequency monitor only)
When open
20 to 30VDC
ON voltage: 1V or less
Continuity check
Across A and C
Across B and C
+W
(3-wattmeter method)
13
W
22
"5" is
common
T1
"SD" is
T2
common.
Normal
Fault
Discontinuity
Continuity
Continuity
Discontinuity
6
325