Siemens SIPROTEC 7SS60, Manual

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Maintenance and Troubleshooting
8-6
7SS60 Manual
E50417-G1176-C132-A2
8.4 Repair/Return
It is recommended to refrain strictly from repairing units or modules, because they
contain especially selected components, which must be handled according to the reg-
ulations for EED (electrostatic endangered devices). In the first place, special tech-
niques are required for working with the printed circuit boards, so that the flow-sol-
dered boards and sensitive components are not damaged.
Therefore, if a defect cannot be eliminated by the operations described in chapter 6,
it is recommended to send the complete device or individual peripheral modules back
to the manufacturer. Use the original transport packaging for return. If alternative
packaging is used, this must provide the degree of protection against mechanical
shock as laid down in IEC 255-21-1 Class 2 and IEC 255-21-2 Class 1.
In case it is unavoidable to replace single modules, the EED-regulations have to be
followed (handling of electrostatic endangered devices).
Before you extract the peripheral modules from the housing, pull off the plug-on con-
nectors and unscrew the securing screw on the rear.
Modules fitted in the unit are not endangered.
Note:
Before returning the device, all configuration and setting parameters should be read
out and stored. If the location of jumpers on the p.c.b.s has been changed, the
changed setting should be noted as well.
When a device is returned to you after a successful repair, all jumpers on the p.c.b.
are in the initial state defined by the ordering code (MLFB). The configuration and set-
ting parameters are also reset to the initial delivery state.
Warning!
Hazardous voltages can be present in the device even after disconnection of the sup-
ply voltage (storage capacitors!).
Caution!
Electrostatic discharges via the component connections, the p.c.b. tracks or the con-
necting pin must be avoided under all circumstances by previously touching an
earthed metal surface. This applies equally for the replacement of removable compo-
nents, such as EPROM or EEPROM chips. For transport and returning of individual
modules, electrostatic protective packing material must be used.