Pick-up
The
I
set
setting parameter controls the pick-up of the I> function. This defines the maximum allowed
measured current before action from the function. The function constantly calculates the ratio
between the
I
set
and the measured magnitude (
I
m
) for each of the three phases. The reset ratio of 97 %
is built into the function and is always relative to the
I
set
value. The setting value is common for all
measured phases, and when the
I
m
exceeds the
I
set
value (in single, dual or all phases) it triggers the
pick-up operation of the function.
Table. 5.3.2 - 31. Pick-up settings.
Name
Description
Range
Step
Default
I
set
Pick-up setting
0.10…50.00×I
n
0.01×I
n
1.20×I
n
The pick-up activation of the function is not directly equal to the START signal generation of the
function. The START signal is allowed if the blocking condition is not active.
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. 5.3.2 - 32. Information displayed by the function.
Name
Range
Step
Description
I> LN
behaviour
1: On
2: Blocked
3: Test
4: Test/Blocked
5: Off
-
Displays the mode of NOC block.
This parameter is visible only when
Allow setting of individual LN mode is
enabled in
General menu.
I>
condition
0: Normal
1: Start
2: Trip
3: Blocked
-
Displays status of the protection function.
I> phases
condition
0: Normal
1: Start A
2: Start B
3: Start C
4: Trip A
5: Trip B
6: Trip C
7: Start AB
8: Start BC
9: Start CA
10: Start ABC
11: Trip AB
12: Trip BC
13: Trip CA
14: Trip ABC
-
Displays the status of phases individually.
Expected
operating
time
-1800.000...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 highest phase
current value. If the measured current changes during a fault, the expected
operating time changes accordingly.
Time
remaining
to trip
0.000...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.
I
meas
/I
set
at the
moment
0.00...1250.00
0.01
The ratio between the highest measured phase current and the pick-up value.
A
AQ
Q-T256
-T256
Instruction manual
Version: 2.06
42
© Arcteq Relays Ltd
IM00028
Summary of Contents for AQ-T256
Page 1: ...AQ T256 Transformer protection IED Instruction manual...
Page 2: ......
