Event block name
Event names
NOC3
Phase C Trip OFF
NOC4
Start ON
NOC4
Start OFF
NOC4
Trip ON
NOC4
Trip OFF
NOC4
Block ON
NOC4
Block OFF
NOC4
Phase A Start ON
NOC4
Phase A Start OFF
NOC4
Phase B Start ON
NOC4
Phase B Start OFF
NOC4
Phase C Start ON
NOC4
Phase C Start OFF
NOC4
Phase A Trip ON
NOC4
Phase A Trip OFF
NOC4
Phase B Trip ON
NOC4
Phase B Trip OFF
NOC4
Phase C Trip ON
NOC4
Phase C Trip OFF
The function registers its operation into the last twelve (12) time-stamped registers; this information is
available for all provided instances separately. The register of the function records the ON event
process data for START, TRIP or BLOCKED. The table below presents the structure of the function's
register content.
Table. 5.3.2 - 35. Register content.
Date and time Event
Fault type
Pre-trigger
current
Fault
current
Pre-fault
current
Trip time
remaining
Used SG
dd.mm.yyyy
hh:mm:ss.mss
Event
name
L1-E…L1-L2-L3 Start/Trip
-20ms current
Start/
Trip current
Start
-200ms
current
0 ms...1800s
Setting group
1...8 active
5.3.3 Non-directional earth fault protection (I0>; 50N/51N)
The non-directional earth fault function is used for instant and time-delayed earth fault protection. The
number of stages in the function depend on the device model. The operating characteristics are based
on the selected neutral current magnitudes which the function measures constantly. The available
analog measurement channels are I01 and I02 (residual current measurement) and I0Calc (residual
current calculated from phase current). The user can select these channels to use RMS values, TRMS
values (including harmonics up to 32
nd
), or peak-to-peak values. The blocking signal and the setting
group selection control the operating characteristics of the function during normal operation, i.e. the
user or user-defined logic can change function parameters while the function is running.
The non-directional earth fault function uses a total of eight (8) separate setting groups which can be
selected from one common source.
A
AQ
Q-T256
-T256
Instruction manual
Version: 2.06
46
© Arcteq Relays Ltd
IM00028
Summary of Contents for AQ-T256
Page 1: ...AQ T256 Transformer protection IED Instruction manual...
Page 2: ......