Appendix 11 General Safety Requirements - Mitsubishi Electric MELSEC iQ-R C R12CCPU-V User Manual

Appendix 11
When the power of a C Controller system is turned OFF and ON, the control output may not operate properly temporarily due
to differences in the delay and startup time between the power supply for the C Controller module and the external power
supply (especially, DC power) for the control module.
Signals also may not be output correctly when the external power supply or the C Controller module fails. In terms of fail-safe
and to prevent any incorrect output signals from leading to the entire system failure, configure safety circuits (such as
emergency stop circuits, protection circuits, and interlock circuits) external to the C Controller module for the parts where the
incorrect output may cause damage to the machines or accidents.
This section shows system design circuit examples, considering the points described above.
When the ERR. contact of a power supply module is not used
For AC power
Power supply
Transformer
Fuse
C Controller module
User program Ò
Start switch
RA1
MC
MC Stop switch
Input module
Output module
Ym
L
Yn
RA1
Output module
MC
MC2
MC1
MC1
MC2
*1 The C Controller module starts when RA1 (control starting output) turns ON.
*2 A stop caused by an emergency stop switch or a limit switch.
*3 Configure external interlock circuits for conflicting operations such as forward/reverse rotations and the parts where the incorrect output
may cause damage to the machines or accidents.
General Safety Requirements
For AC and DC power
Power supply
Start/Stop circuit*1
Start switch
Stop switch
MC
Low battery alarm
(Lamp or buzzer)
Turns ON at the
start of C Controller
module user
program.
Output module
MC
Turns OFF the power
supplied to the output
modules by STOP*2.
Output module
Interlock circuits*3
Transformer Transformer
Fuse Fuse
C Controller module
DC power
(-) (+)
Fuse
User program Ó
RA1
MC
RA2
RA2
XM
Ym
L
Yn
RA1
MC MC
MC2
MC1
MC1
MC2

Appendix 11 General Safety Requirements

Use of a voltage relay is recommended.
Low battery alarm
(Lamp or buzzer)
Turns ON at the start of C
Controller module user program.
Turns OFF the power supplied to
the output devices by STOP*2.
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