Functional Description; Detector Function - Protrol IPS2 24 VDC Manual

4 Functional Description

4.1 Detector Function

True Fault Pass Through Earth Fault Detection
Protrol's patented Fault Pass Through earth fault detection is suitable for all indirectly earthed networks. It
is capable of detecting high impedance and arcing earth faults. It analyses the transient nature of phase and
neutral currents and points reliably out the fault direction with respect to the measurement point. Note
that no voltage measurement is necessary for good selectivity at very low currents. The sensitivity is
comparable with that of a directional earth fault protective relay.
At an earth fault the detector will set itself into Trig state and evaluate if the fault is upstream or
downstream the unit. If the fault is downstream, it will switch to Start state. In this mode, the detector
evaluates the I residual current until the Operation Delay has passed. If the residual is high after the set
0
time, the detector will enter Trip state.
Note that both a Start and a Trip indication means that an earth fault has occurred downstream the
detector. A Start without a subsequent Trip indication means that either the fault current is too low, or the
fault was of transient type and was gone after the Operation Delay time. Thus, the Start object, available
remotely, can be used as an early indication of an incipient fault.
Some periods after the disturbance has vanished, the detector returns to its normal state.
High I Detection
0
The IPS2 supervision alarm for high residual current if the steady-state I
pickup level, as specified by the rotary switch on the front panel
The main purpose of this alarm is to indicate that something is wrongly connected, either wrong polarity or
missing phase.
An alarm is indicated by flashing the I
Board.
Overcurrent Detection
The IPS2 unit has one overcurrent stage that can be configured using the rotary switch at the front panel.
Phase Break Detection
The phase break detection alarm is activated - if one phase is "dead" while the other two are "alive", a
phase break is signaled locally and on the system interface. A phase is considered "dead" if the current is
lower than the I pickup level, and "alive" if the current is higher than 4 x the I
0
An alarm is indicated by flashing the I> LED, also see the Section 5.2 IPS2 24 VDC Top Printed Circuit
Board.
1
If the earth fault stage is deactivated, the High I
2
If the earth fault stage is deactivated, the "dead" threshold is set to 5 A while "alive" is 20 A.
Protrol AB
Ullevigatan 19
411 40 Göteborg
> LED, also see the Section 5.2 IPS2 24 VDC Top Printed Circuit
0
steady-state limit is set to 160 A.
0
5
current exceeds 16 times the I
0
1
.
pickup level.
0
Ver 1710 Rev 1
0
2
Tel: 031- 45 82 00
internet: www.protrol.se
e-mail: info@protrol.se