If blocking signal is active when pick-up element activates a BLOCKED signal will be generated and the
function shall not process the situation further. If START function has been activated before blocking
signal it will reset and the release time characteristics are processed as in case of when pick-up signal
is reset.
From blocking of the function a HMI display event as well as time stamped blocking event with
information of the startup current values and fault type is issued.
Blocking signal can be tested also in the commissioning phase of the stage by software switch signal
when relay common and global testing mode is activated.
User settable variables are binary signals from the system. Blocking signal needs to reach the IED
minimum of 5 ms before the set operating delay has passedfor blocking to be active in time.
Operating time characteristics for trip and reset
The operating timers’ behavior of the 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. De nite time
operation (DT) will give trip signal with user given time delay regardless of the measured current as
long as pick-up element is active (independent time characteristics). In the following table are
presented the setting parameters for the function time characteristics.
Table. 5.4.6. - 85. Operating time characteristics setting parameters.
Name
Range
Step
Default
Description
FWD
reset
time
0.000…
1800.000s 0.005s 0.300s
Forward start detection reset time. Starts to count from rst detected forward
(faulty feeder) spike. If in counting another spike is detected resets and starts
from beginning. If runs to end resets the function start signals.
REV
reset
time
0.000…
1800.000s 0.005s 0.300s
Reverse start detection reset time. Starts to count from rst detected reverse
(healthy feeder) spike. If in counting another spike is detected resets and starts
from beginning. If runs to end resets the function start signals.
De nite
operating
time
delay
0.000…
1800.000s 0.005s 0.500s
Operating time counter that starts from beginning of the fault in case if FWD
reset time is running and the function has start signal on. If FWD reset time is
reached and function releases this timer is reset as well.
Spikes to
trip >
1...50
1
2
Calculated cumulative spikes comparator. In order to trip this set amount of
spikes must be exceeded. If set operating time is reached but calculated spike
amount is below this setting function shall release without trip when the FWD
reset time is elapsed.
Events and registers
The IEF function generates events and registers from the status changes of intermittent earth fault
detected, normal earth fault detected, FWD start, REV start, trip and blocked. To main event buffer is
possible to select status “On” or “Off” messages.
In the function is available 12 last registers where the triggering event of the function (start, trip or
blocked) is recorded with time stamp and process data values.
Table. 5.4.6. - 86. Event codes of the IEF function.
Event Number
Event channel
Event block name
Event Code
Description
7296
114
IEF1
0
Start FWD ON
7297
114
IEF1
1
Start FWD OFF
7298
114
IEF1
2
Start REV ON
7299
114
IEF1
3
Start REV OFF
AQ-F255
Instruction manual
Version: 2.00
© Arcteq Relays Ltd
90
