Power Supply Wiring - Mitsubishi A-Melsec A1FXCPU User Manual

7. EXTERNAL WIRING

7.1 Power Supply Wiring

(1) Power supply wiring
(a) Wire the PLC, I/O equipment and power equipment in separate lines as
shown below.
If excessive noise is generated, use isolating transformers.
PC power
Main power
supply
supply
I/O power
supply
Main circuit power supply
(b) 100VAC, 200VAC and 24VDC supply cables should be twisted as tightly as
possible and of the shortest possible length.
Use the largest possible gauge (max. 2mm
any voltage drop.
(c) As a measure against any potential large surges (e.g. due to lightening), use a
surge absorber as shown below.
AC
POINT
(1) Ground the surge absorber (E
(2) When selecting a surge absorber, make due allowance for increases in the
power supply voltage.
PC
T1
T2
I/O equipment
Main circuit equipment
PLC
I/O equipment
E
2
Surge absorber for
E
1 lightening protection
) and the PLC (E
1
7 - 2
MELSEC-A
2 ) for the above cables to minimize
) separately.
2