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Maintenance and Troubleshooting
8.1
General
7SS601 measuring
system
Peripheral
modules
8-2
The 7SS601 measuring system requires no special maintenance.
As the 7SS601 measuring system is almost completely self-monitored, hardware and
software faults are automatically annunciated. This ensures the high availability of the
system.
With detected hardware faults the system blocks itself; drop-off of the "Device ready"
NC relay signals the equipment fault. Faults that are detected in external connection
circuits lead only to the output of an annunciation or to a blocking, depending on the
parameter setting.
Recognized software errors cause the processor to reset and restart. If such a fault is
not eliminated by restarting, further restarts are initiated. If the fault is still present after
three restart attempts, the protective system will switch itself out of service and indica-
tion this condition by the red LED Blocked/Störung on the front panel; drop-off of the
"Device ready" NC relay signals the equipment fault.
The reactions to faults can be called up in chronological sequence as operational an-
nunciations for fault diagnosis (refer to Section 6.1).
The current transformer circuits are permanently monitored by the differential current
supervision, which can be set to high sensitivity. Faults in the current transformer cir-
cuit are detected under the condition that the feeder current is at least 10 % of the nor-
malized rated current I
no
tion ratio).
(rated current of the transformer with the highest transforma-
7SS60 Manual
E50417-G1176-C132-A2
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Table of Contents
Troubleshooting
