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

9.1.2

Failure and Replacement of a Power Supply Module

Initial situation
Both central processing units are at RUN.
The S7-400H is in the Redundant system
mode and one power supply module fails.
Procedure
To change a power supply module in the central rack, perform the following steps:
Step
1 Turn off the power supply (24 V DC for
PS 405 or 120/230 V AC for PS 407).
2 Replace the module.
3 Turn the power supply back on.
Note
If using a redundant power supply PS 407 10A R two power supply modules are
assigned to a CPU 417-4H. If a part of the redundant PS 407 10A R power supply
module fails, the corresponding 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.
S7-400H Programmable Controller Fault-Tolerant Systems
A5E00068197-04
Failure and Replacement of Components During Operation
Failure
What Has To Be Done?
How Does the System React?
Partner CPU switches to Solo mode.
Partner CPU reports the event in the
diagnostic buffer and via OB 72.
How Does the System React?
Entire subsystem is turned off
(system operating in Solo mode).
-
CPU executes the self-tests.
CPU performs automatic LINK-UP
and UPDATE.
CPU changes to RUN (Redundant
system mode) and now operates
as the standby CPU.
9-5