Function blocking
The block signal is checked in the beginning of each program cycle. The blocking signal is received
from the blocking matrix in the function's dedicated input. If the blocking signal is not activated when
the pick-up element activates, a START signal is generated and the function proceeds to the time
characteristics calculation.
If the blocking signal is active when the pick-up element activates, a BLOCKED signal is generated and
the function does not process the situation further. If the START function has been activated before the
blocking signal, it resets and processes the release time characteristics similarly to when the pick-up
signal is reset.
The blocking of the function causes an HMI display event and a time-stamped blocking event with
information of the startup current values and its fault type to be issued.
The blocking signal can also be tested in the commissioning phase by a software switch signal when
the relay's testing mode "Enable stage forcing" is activated (
General
→
Device).
The variables the user can set are binary signals from the system. The blocking signal needs to reach
the device minimum of 5 ms before the set operating delay has passed in order for the blocking to
activate in time.
Operating time characteristics
The operating timers’ behavior during a function can be set depending on the application. The same
pick-up signal starts both timers. When retrip is used the time grading should be set as follows: the
sum of specific times (i.e. the retrip time, the expected operating time, and the pick-up conditions'
release time) is shorter the set CBFP time. This way, when retripping another breaker coil clears the
fault, any unnecessary function triggers are avoided.
The following table presents the setting parameters for the function's operating time characteristics.
Table. 5.4.8 - 96. Setting parameters for operating time characteristics.
Name
Range
Step
Default
Description
Retrip
0: No
1: Yes
-
1: Yes
Retrip enabled or disabled. When the retrip is disabled, the output will not
be visible and the TRetr setting parameter will not be available.
Retrip
time
delay
0.000…1800.000s 0.005s 0.100s
Retrip start the timer. This setting defines how long the starting condition
has to last before a RETRIP signal is activated.
CBFP
0.000…1800.000s 0.005s 0.200s
CBFP starts the timer. This setting defines how long the starting condition
has to last before the CBFP signal is activated.
The following figures present some typical cases of the CBFP function.
A
AQ
Q-M257
-M257
Instruction manual
Version: 2.07
© Arcteq Relays Ltd
IM00021
113
Summary of Contents for AQ-M257
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