Name
Range
Step
Description
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.
Z
meas
/Z
set
at
the moment
0.00...1250.00
0.01
The ratio between the lowest measured impedance 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 impedance values.
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.
Events and registers
The underimpedance protection function (abbreviated "UIM" in event block names) generates events
and registers from the status changes in START, TRIP and BLOCKED. The user can select which event
messages are stored in the main event buffer: ON, OFF, or both. The function offers two (2)
independent stages; the events are segregated for each stage operation.
The events triggered by the function are recorded with a time stamp and with process data values.
Table. 5.3.22 - 183. Event codes.
Event number
Event channel
Event block name
Event code
Description
7104
111
UIM1
0
Start ON
7105
111
UIM1
1
Start OFF
7106
111
UIM1
2
Trip ON
7107
111
UIM1
3
Trip OFF
7108
111
UIM1
4
Block ON
7109
111
UIM1
5
Block OFF
9536
149
UIM2
0
Start ON
9537
149
UIM2
1
Start OFF
9538
149
UIM2
2
Trip ON
9539
149
UIM2
3
Trip OFF
9540
149
UIM2
4
Block ON
A
AQ
Q-G215
-G215
Instruction manual
Version: 2.04
259