FANOX SIA-C, User Manual

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The function operates according to the following automaton. The automaton consists of five
states, in three of those states the relay works with normal setting group (the table adjusted in
general settings), and in the other two, with the new settings group.
The relay uses the current level to determine the circuit breaker state (open or closed). If the
current is less than 10% of the rated level, it is understood that the line is open.
The relay usually operates with the settings in their active table. When the circuit breaker opens,
a timer “No Load Time” starts. After this time, the relay considers that the circuit breaker is open,
so the CLP function is in working conditions.
Once the circuit breaker is closed, CLP function picks-
up and “Cold load time” starts to count.
During this time the relay will work with the new setting group regardless of the circuit breaker
situation, this is, without taking into account whether the circuit breaker is maintained closed or is
open.
When the setting group changed occurs, not all the protection functions change, only 50P,
50/51P, 50N/G and 50/51N/G functions are modified to new settings.