Failure And Replacement Of A Power Supply Module - Siemens SIMATIC S7-400H System Manual

Failure and replacement of components during operation
16.2 Failure and replacement of components during operation
16.2.2

Failure and replacement of a power supply module

Starting situation
Both CPUs are in RUN.
Failure
The S7-400H is in redundant system mode and a
power supply module fails.
Procedure
Proceed as follows to replace a power supply module in the central rack:
Step
1
2
3
Note
Redundant power supply
If you use a redundant power supply (PS 407 10A R), two power supply modules are
assigned to one fault-tolerant CPU. If a part of the redundant PS 407 10A R power supply
module fails, the associated CPU keeps on running. 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.
268
What has to be done?
Turn off the power supply (24 V DC for PS
405 or 120/230 V AC for PS 407).
Replace the module.
Switch the power supply module on again.
How does the system react?
The partner CPU switches to single mode.

The partner CPU reports the event in the

diagnostic buffer and in OB 72.
How does the system react?
The entire subsystem is switched off

(system operates in single mode).
–
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.
System Manual, 03/2012, A5E00267695-11
S7-400H