Failure and replacement of components during redundant operation
11.1 Failure and replacement of central components
CPU 410-5H Process Automation
System Manual, 09/2014, A5E31622160-AB
187
11.1.2
Failure and replacement of a power supply module
Starting situation
Both CPUs are in RUN.
Failure
How does the system react?
The S7-400H is in redundant system mode and a
power supply module fails.
•
The partner CPU switches to single mode.
•
The partner CPU reports the event in the
diagnostic buffer and in OB 72.
Procedure
Proceed as follows to replace a power supply module in the central rack:
Step
What to do?
How does the system react?
1
Turn off the power supply (24 V DC for PS
405 or 120/230 V AC for PS 407).
•
The entire subsystem is switched off
(system operates in single mode).
2
Replace the module.
–
3
Switch the power supply module on again.
•
The CPU executes the self-tests.
•
The CPU performs an automatic LINK-
UP and UPDATE.
•
The CPU changes to RUN (redundant
system mode) and operates as reserve
CPU.
Note
Redundant power supply
If you use a redundant power supply with two PS 407 10A R or PS 405 10A R, two power
supply modules are assigned to one fault-tolerant CPU. The associated CPU continues to
run if one of the redundant power supply modules fails. The defective part can be replaced
during operation.
Other power supply modules
If the failure concerns a power supply module outside the central rack (e.g. in the expansion
rack or in the I/O device), the failure is reported as a rack failure (central) or station failure
(remote). In this case, simply switch off the power supply to the power supply module
concerned.