Mitsubishi Electric FR-A700 Series, Technical Manual

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542
SELECTION
(d) This function is valid for V/F control only.
(When [ Pr. 72 = 25], V/F control is
automatically selected.)
(e) A sine wave filter and MT-HC can not be used
together.
(8) Wiring of control circuit
1) Use twisted or shielded cables for connection with
the control circuit terminals (10, 2, 5, 1, 4, AM). Do
not earth (ground) the shield but connect it as
indicated below. (Keep the other end of the shield
open)
2) Use twisted or shielded cables for connection with
the display (frequency) meter terminals (FM, SD)
over a wiring distance of 200m maximum. If the
distance exceeds 200m, the display (frequency)
meter reading may result in a larger error.
3) Wire the control circuit cables away from the
power line over the shortest distance.
(9) Countermeasures against external noise
1) Strengthening the countermeasures against noise
The FR series inverters are sufficiently protected
from noise. However, extremely large external
noise may cause the inverter to malfunction.
When there is such external noise that cannot be
eliminated, wire the inverter in accordance with
the following figure.
2) Remote control, etc.
Acting as an antenna, the single lines are
susceptible to external noise. Therefore, run the
signal lines as far as possible from the power line.
If the inverter is controlled 30m or further away
from its installation position, it is recommended to
use any of the following:
(a) Speed setting device
Use the FR-FK motorized speed setter. (For
the operation information, see the
corresponding manual.)
(b) External start/stop signal
Add a relay in the vicinity of the inverter.
(c) Cable
Use twisted or twisted shielded cables.
(d) Surge suppressors
Install surge suppressors to the coils of the
relays, valves etc. around the inverter.
Sine wave filter
*
Inverter
(Carrier 2.5kHz)
Inverter output voltage
wave form
Wave form at a motor
terminal
(Capacitor)
IM
Motor
U X
V Y
W Z
Voltage
Current
+
-
0
Reactor
Capacitor
Within 30m
<Correct>
Inverter
10
2
5
10
2
5
Wrong connection
Inverter
<Incorrect>
[Example 1] Shielded cables
Connecting the shielded cables
Within
30m
Provide a shielding terminal
<Correct>
Inverter
10
2
5
10
2
5
Wrong connection
<Incorrect>
Inverter
[Example 2] Shielded cables joined
Connecting the shielded cables
MCCB
R
S
T
U
V
W
Inverter
Start
STF(STR), etc
SD
RES
SD
Reset
10
2
5
Frequency setting
potentiometer
FM
SD
M
Motor
Display
(frequency meter)
Noise reduction techniques
18 1.5
31.5±
6
4 dia. hole
10 3
10 or less
15 1
48 1.5
10 or less
10 3
0.5 F1W50
Blue vinyl cord
Vinyl sheath
Red vinyl cord
Composition (Unit: mm)
200 or more 200 or more
[Example]972A-2003 504 11
(manufactured by MATSUO ELECTRIC CO.,LTD.)