Supervisory Functions
141
7SS52 V4 Manual
C53000-G1176-C182-3
Bay unit failure
All serial links between the bay unit and the central unit are continuously monitored in
the central unit. A failure or disturbance of an operating bay unit leads to the output of
an alarm but not to a system reset. The same is true for a failure or disturbance of the
link between bay unit and central unit.
If the connection fails, the protection is blocked in accordance with the settings of the
parameter
(
CU
), either selectively for the zone for which the
respective bay unit is switched and, if required, for the phase, or completely.
Measured value er-
rors
The analog inputs of the bay unit are cyclically monitored (Chapter 5.5.1.3, page 142).
The measured value error consists of the offset monitoring and the current sum mon-
itoring. Furthermore, the measured values read in with gain 1 and 16 are checked for
plausibility to each other. If one of these errors occurs, the protection is immediately
blocked - selectively or entirely - and the error is signalled. If the error has been
present longer than 1 s, the blocking is permanent and can only be reset with a warm
restart.
Figure 5-32 Simplified logic of the monitoring function
Isolator malfunc-
tion
Isolators are monitored with regard to runtime, isolator status plausibility and auxiliary
voltage. An isolator malfunction with the parameter
) set
and the parameter
CU
causes a blocking of only the protection zone to which the feeder with the faulty isola-
tor is connected.
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