# Mitsubishi Electric FR-A800 Instruction Manual Page 116

Measuring points and instruments
Item
Measuring point
Across 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
Across 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
V
W, and W and U
2
Output side current
U, V and W line
I
2
currents
U, V, W and
Output side power
across U and V, V and
P
2
W
Calculate in similar manner to power supply side power factor.
Output side power
factor
Pf
2
Pf
2
Converter output
Across P/+ and N/-
Across 2, 4(+) and 5
Frequency setting
signal
Across 1(+) and 5
Across 10(+) and 5
Frequency setting
power supply
Across 10E(+) and 5
Across AM(+) and 5
Across CA(+) and 5
Frequency meter
signal
Across FM(+) and SD
Across STF, STR, RH,
Start signal
RM, RL, JOG, RT, AU,
Select signal
STOP, CS, RES,
Reset signal
MRS(+) and SD (for
Output stop signal
sink logic)
Across A1 and C1
Fault signal
Across B1 and C1

Use an FFT to measure the output voltage accurately. A tester or general measuring instrument cannot measure accurately.

When the carrier frequency exceeds 5 kHz, 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.195 ABC1 terminal function selection is the 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 (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 (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 used.)
(internal resistance 50 kΩ or more)
Moving-coil type
(such as tester)
PRECAUTIONS FOR MAINTENANCE AND INSPECTION
Remarks (reference measured value)
Commercial power supply
Within permissible AC voltage fluctuation

(Refer to
page
120.)

P
= W
+ W
+ W
(3-wattmeter method)
1
11
12
13

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
2
= W
21
+ W
22
2-wattmeter method (or 3-wattmeter method)
Inverter LED is lit. 1.35  V
0 to 10 VDC, 4 to 20 mA
0 to ±5 VDC and 0 to ±10 VDC
5.2 VDC
10 VDC
Approximately 10 VDC at maximum
frequency
(without frequency meter)
frequency
Approximately 5 VDC at maximum
frequency
(without frequency meter)
T1
8VDC
T2
Pulse width T1: Adjust with C0 (Pr.900).
Pulse cycle T2: Set with Pr.55.
(frequency monitor only)
When open
20 to 30 VDC
ON voltage: 1 V or less
Continuity check

[Normal]
Across A1 and C1 Discontinuity
Across B1 and C1 Continuity
1
"5" is .
common
"SD" is
common
[Fault]
5
Continuity
Discontinuity
115