External Wiring Precautions - Mitsubishi Electric MELSEC-F FX3G Series User Manual

FX Series Programmable Controllers
3G
User's Manual - Hardware Edition

20.9.4 External wiring precautions

1. Protection circuit for load short-circuits
A short-circuit at a load connected to an output terminal
could cause burnout at the output element or the PCB.
To prevent this, a protection fuse should be inserted at the
output.
2. Micro current load
The PLC's internal Triac output circuit is equipped with a
turn-off C-R absorber. When connecting a very low
current load of "0.4VA/100V AC or less or 1.6VA/200V AC
or less", please connect a surge absorber parallel to the
load.
Select the rated voltage of a surge absorber that is
suitable for the load being used. Refer to the table below
for other specifications.
Static electricity capacity
Resistance value
Reference
Manufacturer
Okaya Electric Industries Co., Ltd.
3. Interlock
For loads such as forward/reverse contactors, etc., where
a hazardous condition could result if switched ON
simultaneously, an external interlock should be provided
for interlocking the PLC's internal programs as shown to
the right.
4. In-phase
PLC output contacts (*) should be used in an "in-phase"
manner.
378
Guide
Approx. 0.1 F
Approx. 100 to 200
Model name
CR-10201
Load
Fuse
Micro current load
U
Manufacturer
Rubycon Corporation
Interlock
U
U
PLC output
element
*
Bad
*
Good
*
20 Terminal Block
20.9 FX-16EYS-TB
0 to 7
COMn
Terminal block
Surge
absorber
Model name
250MCRA104100M B0325
Forward
limit
Forward
Reverse
Reverse
limit
*
U
U
U
U