Wiring Of I/O Equipment; Grounding - Mitsubishi Electric C70 Connection Manual

4.1.2 Wiring of I/O equipment

(a) Insulation-sleeved crimping terminals cannot be used with the terminal block.
It is recommended to cover the wire connections of the crimping terminals with mark or insulation
tubes.
(b) The wires used for connection to the terminal block should be 0.3 to 0.75mm
(0.11inch) or less in outside diameter.
(c) Run the input and output lines away from each other.
(d) When the wiring cannot be run away from the main circuit and power lines, use a batch-shielded cable
and ground it on the CNC control unit side.
(e) Where wiring runs through piping, ground the piping without fail.
(f) Run the 24VDC input line away from the 100VAC and 200VAC lines.
(g) Wiring of 200m (656.17ft.) or more distance will give rise to leakage currents due to the wiring
capacity, resulting in a fault.
Refer to the troubleshooting chapter of the I/O Module User's Manual.
(h) As a countermeasure to power surge due to thunder, separate AC lines from DC lines and connect a
surge absorber for thunder (refer to "Wiring and Connecting: Precautions:Power supply wiring").
Without the countermeasures, an I/O device failure could occur due to thunder.

4.1.3 Grounding

To ground the cable, follow the steps (a) to (c) shown below.
(a) Use the dedicated grounding as independent as possible.
(Ground resistance: 100Ω or less)
(b) When CNC control unit and another equipment cannot be departed to ground the cable each other,
use (ii) Common Grounding shown below.
( i )
BEST
C70 Unit
QXxxxx QXxxxx QXxxxx QXxxxx QXxxxx QXxxxx
M E L S E C M E L S E C M E L S E C QJ71E71-100 QJ71E71-100 QJ71E71-100 QJ71E71-100 QJ71E71-100 QJ71E71-100
POWER POWER POWER
MITSUBISHI MITSUBISHI MITSUBISHI
Grounding
(Ground resistance:
100 or less)
(c) Use the grounding cable of 2 mm
Position the ground-contact point as nearly to CNC control unit as possible, and use the total length of
the grounding cable as short as possible.
IN/OUT put module
IN
OUT
( i i )
Another
equipment
M E L S E C M E L S E C M E L S E C
QXxxxx QXxxxx QXxxxx POWER POWER POWER
MITSUBISHI MITSUBISHI MITSUBISHI
Grounding
(Ground resistance:
100 or less)
2
or more.
BETTER
Another
C70 Unit
equipment
QXxxxx QXxxxx QXxxxx QXxxxx QXxxxx QXxxxx QXxxxx QXxxxx QXxxxx
QJ71E71-100 QJ71E71-100 QJ71E71-100 QJ71E71-100 QJ71E71-100 QJ71E71-100
Grounding
(Ground resistance:
100 or less)
C70 Connection Manual
4.1 Precautions
2
in core and 2.8mm
( i i i )
NG
Another
equipment
M E L S E C M E L S E C M E L S E C
POWER POWER POWER
MITSUBISHI MITSUBISHI MITSUBISHI
69