Replacing A Power Supply Module - Siemens S7-400 Installation Manual

Maintenance
7.2

Replacing a Power Supply Module

Slot Numbering
If you have provided the modules in your system with slot numbering, you must
remove the number from the old module when replacing it and apply the number to
the new module.
Removing the Module (Ignore Steps 1 and 2 When Using Redundant Power
Supply Modules)
1. Set the CPU mode switch to STOP.
When you replace the power supply module in an ER, the CR may remain in the
RUN state, depending on CPU programming. You can back up the data in the
ER via the EXT. BATT. socket of the receive IM.
2. If you wish to back up the data in the CPU, you can use the EXT. BATT. socket
of the CPU (see Reference Manual, Chapter 4).
3. Set the standby switch of the power supply module to
4. Set the line disconnector to OFF.
5. Remove the cover.
6. Remove the backup battery/batteries if applicable.
7. Disconnect the power supply connector from the power supply module.
8. Loosen the mounting screws of the module.
9. Swing the module out.
Installing a New Module
1. Check the voltage selector switch.
2. Attach the new module of the same type and swing it downwards.
3. Screw the module on.
4. Check that the power disconnector is set to OFF and the standby switch to
5. Plug in the power supply connector at the power supply module.
6. Insert the backup battery/batteries, if applicable.
7. Close the cover.
8. Set the power disconnector to ON.
9. Set the standby switch of the power supply module to I (output voltages at rated
value).
10.Set the CPU mode switch to RUN if applicable.
How the S7-400 Behaves after Exchanging Modules
If an error occurs after replacing a module, you can read out the cause of the error
from the diagnostic buffer.
7-4
S7-400 and M7-400 Programmable Controllers Hardware and Installation
(0 V output voltages).
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A5E00069481-04