Repairs - Siemens SIMATIC S5-95F Manual

S5-95F

18.11 Repairs

When installing, disassembling or modifying your system, you must proceed as follows:
Table 18-8. Hardware Installation, Removal and Replacement
Installation, Removal and
Replacement of:
Basic unit
Bus units
I/O interface modules
40-pin onboard I/O connectors
9-pin sub D connectors for interrupt
and counter inputs
I/O modules
* When I/O modules are inserted or removed in RUN mode, the S5-95F disables the outputs for approximately 300 ms.
Moreover, voltage dips may ensue, causing the S5-95F to go to STOP.
Safety Note
If you modify the bus configuration while the S5-95F is at RUN, the PLC initializes the
bus. This takes approximately 300 ms, and causes disabling of the outputs for the same
length of time. Under worst-case conditions, it is also possible that
• there will be voltage dips on the internal bus which may cause the S5-95F to go to
STOP
• execution of OB13, if pending at the time, will not take place punctually, causing the
S5-95F to go to STOP
Safety Note
An overall reset must not be performed until all faulty components have been repaired,
and is the sole responsibility of the user!
In failsafe systems, an overall reset is considered relevant to a system's failsafety
because the error info in the system event DB is lost when an overall reset is executed.
Safety Note
When I/O modules are inserted and removed, the contacts of bus units 700-8MA11 and
700-8MA21 are exposed and unprotected. Remember that, in this case, the S5-95F's
EMC is reduced, and the strict requirements to DIN IEC 801-2 are no longer fulfilled.
When handling modules, always be sure to follow the guidelines and regulations for the
prevention of electrostatic charge with the utmost care (see Appendix D).
EWA 4NEB 812 6210-02
Rules for Failsafe Operation of an S5-95F
POWER
Supply voltage
OFF
POWER OFF
Irrelevant STOP/RUN
Mode Load Voltage
Irrelevant Irrelevant
Irrelevant Irrelevant
*
Irrelevant
18-21