Siemens siprotec 7SA522, User Manual

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Routine Checks and Maintenance
9-9
7SA522 Manual
C53000-G1176-C119-2
9.5 Corrective Action / Repairs
9.5.1 Software Procedures
A restart of the processor system, as described in Section 9.2, can be done as an at-
tempt to solve a problem. Setting changes can be made to solve simple problems,
such as sporadic alarms from elements of the measured value supervision. These at-
tempts of solving problems can be done while the device is in service.
If a processor restart or setting change does not remedy the problem, then no further
action should be done while the device is in service. Instead, replace the device with
a tested spare.
9.5.2 Hardware Procedures
Hardware modifications or repair should be limited in scope to changes that are abso-
lutely necessary. Some examples of hardware repair are changing the mini-fuse in the
power supply and replacing a printed circuit board or module.
Hardware modifications or repair should only be done by experienced personnel. Do
not insert or extract a printed circuit board unless the device is completely isolated.
Soldering work must not be done on the printed circuit boards.
Disassembling the
Device The device must be disassembled if work is to be done on the printed circuit boards.
The procedure below should be used.
o
Prepare area of work. Provide a grounded mat for protecting components subject to
damage from electrostatic discharges (ESD). The following equipment is needed:
−
Screwdriver with a 5 to 6 mm or
1
/
4
inch tip.
−
#1 Phillips screwdriver.
−
4.5 mm socket or nut driver.
o
Isolate the power supply by opening the protective switches (test switches, fuses, or
miniature circuit breakers) for both terminals.
o
Disconnect all communication cables from the device. Carefully remove optical fibres
from the device. Apply protective caps to the fibber ends and the communication ports
on the device.
These activities do not apply if the device is for surface mounting.
o
Unfasten the screw-posts of the D-subminiature connector on the back panel at loca-
tion “A.”
This activity does not apply if the device is for surface mounting.
o
If the device has more communication interfaces at locations “B” and/or “C” on the
rear, the screws located diagonally to the interfaces must be removed.
These activities are not necessary if the device is for surface mounting.
o
Remove the corner covers on the front panel and loosen the screws that are holding
the front panel to the device case.