The protection function uses a formula which takes the highest measured value of the phase's
current, then subtracts from this value the lowest measured value of the phase's current, and finally
divides the result with the mean of all phases. This value is then compared to the
Iset Alarm and
the
Iset Trip parameters. The function constantly calculates the ratio between the I
set
and the
calculated magnitude (
I
unb
). The reset ratio of 97 % is built into the function and is always relative to
the
I
set
value.
Table. 5.4.2.2 - 58. Pick-up settings.
Name
Range
Step
Default
Description
Iset Alarm
0.10…50.00×I
n
0.01×I
n
1.20×I
n
Defines the pick-up setting for the alarm.
Iset Trip
0.10…50.00×I
n
0.01×I
n
1.20×I
n
Defines the pick-up setting for the trip.
Definite time delay alarm
0.000…1 800.00s
0.005s
0.04s
Defines the definite time delay for the ALARM signal.
Definite time delay trip
0.000…1 800.00s
0.005s
0.04s
Defines the definite time delay for the TRIP signal.
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. 5.4.2.2 - 59. Information displayed by the function.
Name
Range
Step
Description
IUC> condition
0: Normal
1: Blocked
2: StartOn(Alarm)
3: StartOn(Alarm&Trip)
4: StartOn(Trip)
5: AlarmOn
6: StartOn
7: StartOn,AlarmOn
8: TripOn
9: AlarmOn,TripOn
10: MultistatusOn
-
Displays status of the protection function.
Expected time
to Alarm
-1800.000...1800.000s 0.005s Displays the expected time to alarm when a fault occurs.
Time remaining
to Alarm
0.000...1800.000s
0.005s When the function has detected a fault and counts down time towards an
alarm, this displays how much time is left before tripping occurs.
I
meas
/I
set
Alarm
at the moment
0.00...1250.00
0.01
The ratio between the highest measured current unbalance and the pick-
up value.
Expected time
to Trip
-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.
A
AQ
Q-C215
-C215
Instruction manual
Version: 2.07
© Arcteq Relays Ltd
IM00040
109