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4 SETUP AND PROCEDURE BEFORE STARTING THE OPERATION
4.4 Wiring
4.4.1 Wiring precautions
PLC
Inverter
Terminal block
Provide a clearance
of 150 mm (5.9 inch) or
more from I/O wires to
high voltage equipment
such as inverters. (Also
exercise caution for
wiring inside the panel.)
AC
motor
• Grounding the twisted pair shielded wire is performed on the encoder side (relay box). (This example shows
connection with 24 V sink load.
Current for the encoder
To φ A
To φ B
To QD62 (E/D)
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The following explains how to wire the pulse generator and the controller to the QD62(E/D).
In order to fully utilise the functions of the QD62(E/D) and ensure system reliability,
external wiring having a minimum of noise effect must be provided.
The precautions regarding external wiring are described below.
(1) Different terminals have been prepared for connection depending on the voltage
of the input signal. Connecting a terminal of incorrect voltage may result in
malfunction or mechanical failure.
(2) For 1-phase input, always perform pulse input wiring on the Phase A side.
(3) For the QD62(E/D), count will be performed if pulse status noise is input and a
miscount will result.
(4) Provide the following measures against noise for high-speed pulse input:
(a) Always use a shielded twisted pair cable and provide grounding.
(b) Avoid placing the twisted pair cables or input/output cables. Place the cable
at least 150 mm (5.9 inch) from such wires and perform wiring using the
least distance as possible.
(5) An example of wiring incorporating measures against noise is shown below:
QD62 (E/D)
Do not enclose solenoids and inductive loads together within the same metal conduit.
If a sufficient distance cannot be secured to isolate ducts and other wires from a high-
voltage line, use CVVS or other shielded wire for the high-voltage line.
Carrier
+ 24 V
0 V
The distance between the encoder and relay box
must be short. Allowing a long distance between
the QD62 (E/D) and the encoder may cause a
Relay box
voltage-drop problem. Using a tester or other
measuring device, confirm that the voltage at the
terminal block of the relay box doesn't exceed the
rated voltage when the encoder is in operation or
at standstill. If a substantial voltage drop occurs,
increase the wire size or use a 24 V DC encoder
Encoder
with minimal current consumption.
To the encoder
φ A
φ B
The shielded wire for the encoder
24V
and twisted pair shielded wire are
E
connected inside the relay box .
If the shielded wire for the encoder
E
is not grounded inside the encoder,
ground it in the relay box, as
indicated by the dotted line.
MELSEC-Q
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