Read-only parameters
The relay's
Info page displays useful, real-time information on the state of the protection function. It is
accessed either through the relay's HMI display, or through the setting tool software when it is
connected to the relay and its Live Edit mode is active.
Table. 5.4.13 - 133. Information displayed by the function.
Name
Range
Step
Description
U1/2
>/< LN
behaviour
1: On
2: Blocked
3: Test
4: Test/Blocked
5: Off
-
Displays the mode of VUB block.
This parameter is visible only when
Allow setting of individual LN
mode is enabled in General menu.
U1/2 >/<
Pick-up
setting
0.0...1 000 000.0V
0.1V
The primary voltage required for tripping. The displayed pick-up voltage
level depends on the pick-up setting and the voltage transformer
settings.
Expected
operating
time
0.000...1800.000s
0.005s
Displays the expected operating time when a fault occurs. When IDMT
mode is used, the expected operating time depends on the measured
voltage value. If the measured voltage changes during a fault, the
expected operating time changes accordingly.
Time
remaining
to trip
-1800.000...1800.000s 0.005s
When the function has detected a fault and counts down time towards a
trip, this displays how much time is left before tripping occurs.
U
meas
/U
set
at the
moment
0.00...1250.00U
m
/U
set
0.01U
m
/U
set
The ratio between the measured voltage and the pick-up value.
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 the release time characteristics are processed 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 voltage 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 for trip and reset
The operating timers’ behavior during a function can be set for TRIP signal and also for the release of
the function in case the pick-up element is reset before the trip time has been reached. There are three
basic operating modes available for the function:
• Instant operation: gives the TRIP signal with no additional time delay simultaneously with the
START signal.
A
AQ
Q-M257
-M257
Instruction manual
Version: 2.07
160
© Arcteq Relays Ltd
IM00021
Summary of Contents for AQ-M257
Page 1: ...AQ M257 Motor protection IED Instruction manual...
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