Chapter 11 Installation and Wiring
11-12
4) Use more than 2 mm
2
cable for earth. Place the earth point near this PLC as possible to have the short
length of earth cable.
5) Separate LG of power module and FG of base board for earth.
A) dedicated earth : Best B) common earth : Good C) common earth: Poor
6) If the abnormal operation is found according to the earth, separate FG of the base from the earth.
11.2.4 Cable Specification for Wiring
The specification of cable used for wiring is as below.
Cable specification (mm
2
)
Type of External
Connection
Low limit
High limit
Digital Input
0.18 (AWG24)
1.5 (AWG16)
Digital Output
0.18 (AWG24)
2.0 (AWG14)
Analog I/O
0.18 (AWG24)
1.5 (AWG16)
Communication
0.18 (AWG24)
1.5 (AWG16)
Main power
1.5 (AWG16)
2.5 (AWG12)
Protection earth
1.5 (AWG16)
2.5 (AWG12)
LG
FG
LG
FG
LG
FG
P
owe
r
P
owe
r
P
owe
r