Output Circuit Structure - Mitsubishi A-Melsec A1FXCPU User Manual

8. SPECIFICATIONS AND WIRING OF THE I/O BLOCKS

8.4.3 Output circuit structure

DC load
AC load
Use in the
same phase
Interlock
Inductive load
+
PLC output
contact
Commutating
diode
Inductive load
PLC output
contact
Surge absorber
*
*
*
*
Interlock
Forward
rotation limit
Reverse
rotation limit
PLC output contact
8 - 9
- Connect a commutating diode in parallel with the DC
inductive load.
Without this diode, the contact life will be reduced remarkably.
The commutating diode selected should be the one whose inverse
dielectric withstand voltage is 5 to 10 times greater than the load
voltage and whose forward current is equal to or higher than the
load current.
Noise reduces if a surge absorber is provided in
parallel with the AC inductive load.
It is recommended to use the output contacts (*)
of the PLC in the same phase.
Loads such as forward and reverse
Forward
rotation rotation contactors, which will cause
hazardous conditions if they are switched
on at the same time, must be interlocked
Reverse
in the program in the PLC and also be
rotation
interlocked outside the PLC.
MELSEC-A