Mitsubishi FR-A721-11K Instruction Manual page 185

Measurement of main circuit voltages,
currents and powers
Measuring points and instruments
Item Measuring Point
Across R/L1 and S/
Power supply voltage
L2, S/L2 and T/L3,
V
1
T/L3 and R/L1
Power supply side
R/L1, S/L2, and T/L3
current
line currents
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
= ————— × 100%
Pf
Pf
1 1
Across U and V,
Output side voltage
V and W
V
2
and W and U
Output side current U, V and W line
I currents
2
U, V, W and
Output side power
U and V,
P
2
V and W
Calculate in similar manner to power supply side power factor.
Output side power
factor
= ————— × 100%
Pf
2
Pf
2
Converter output Across P/+ and N/−
Across 2 and 5
Frequency setting
Across 4(+) and 5
signal
Across 1(+) and 5
Across 10 (+) and 5
Frequency setting
power supply Across 10E(+) and 5
Across AM(+) and 5
Frequency meter
signal
Across FM(+) and SD
Across SD and the
following:
Start signal
STF, STR, RH, RM,
Select signal
RL, JOG, RT, AU,
STOP, CS (+)
Reset Across RES (+) and SD
Output stop Across MRS (+) and SD
Across A1 and C1
Alarm signal
Across B1 and C1
*1 Use an FFT to measure the output voltage accurately. A tester or general measuring instrument cannot measure accurately.
*2 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. If the wiring length between the inverter and motor is long, the instrument and CT may generate
heat due to line-to-line leakage current.
*3 When the setting of Pr. 195 ABC1 terminal function selection is positive logic
*4 A digital power meter (designed for inverter) can also be used to measure.
178
Measuring Instrument
Moving-iron type AC
voltmeter
*4
Moving-iron type AC
ammeter
*4
Digital power meter
(designed for inverter) or
lectrodynamic type
e
single-phase wattmeter
P
1
× I
V
3
1 1
Rectifier type AC voltage
meter
*1 *4
(Moving-iron type cannot
measure)
Moving-iron type AC
ammeter
*2 *4
Digital power meter
(designed for inverter) or
lectrodynamic type
e
single-phase wattmeter
P
2
× I
V
3
2 2
Moving-coil type (such as
tester)
Moving-coil type
(Tester and such may be
used)
(Internal resistance:
50kΩ or larger)
Moving-coil type
(such as tester)
Remarks (Reference Measured Value)
Commercial power supply
Within permissible AC voltage fluctuation
(Refer to page 182)
P1=W11+W12+W13 (3-wattmeter method)
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 + W
2 21 22
2-wattmeter method (or 3-wattmeter method)
Inverter LED display is lit. 1.35
0 to 10VDC, 4 to 20mA
0 to ±5VDC, 0 to ±10VDC
5.2VDC
10VDC
Approximately 10VDC at maximum frequency
(without frequency meter)
Approximately 5VDC at maximum frequency
(without frequency meter)
T1
8VDC
T2
Pulse width T1:
Adjusted by C0 (Pr. 900)
Pulse cycle T2: Set by Pr. 55
(Valid for frequency monitoring only)
When open
20 to 30VDC
ON voltage: 1V or less
Electric continuity check
*3
<Normal>
Across A1-C1 Discontinuity
Across B1-C1 Continuity
×
V1
"5" is
common
"SD" is
common
<Abnormal>
Continuity
Discontinuity