4506
70
RTD2
26
S14 Meas Ok
4507
70
RTD2
27
S14 Meas Invalid
4508
70
RTD2
28
S15 Meas Ok
4509
70
RTD2
29
S15 Meas Invalid
4510
70
RTD2
30
S16 Meas Ok
4511
70
RTD2
31
S16 Meas Invalid
5.4.12. Arc fault protection IArc>/I0Arc>(50Arc/50NArc)
Arc faults occur because of insulation failure, incorrect operation of the protected device, corrosion,
overvoltage, dirt, moisture, incorrect wiring or even because of aging caused by electric load. To
minimize the effects of an arc fault it’s important to detect the arc as fast as possible. Using arc sensors
to detect arc faults is much faster than merely measuring currents and voltages. In busbar protection
using just the normal protection IEDs could be too slow to disconnect arcs under safe time. For
example, when setting up overcurrent protection relay controlling the feeder breakers operation time
could be necessary to delay for hundreds of milliseconds after sensing the fault to achieve selectivity.
This delay can be avoided by using arc protection. To extent the speed of arc protection operation arc
protection card has high speed output as well to give tripping signal faster.
Figure. 5.4.12. - 118. An IED equipped with arc protection card has 4 sensor channels. Up to three sensors can be connected to
each channel.
Arc protection card has four sensor channels. Up to three arc point sensors may be connected to each
channel. Sensor channels support Arcteq AQ-01 (light sensing) and AQ-02 (pressure and light
sensing) units. Optionally protection function can be applied with phase or residual current condition.
This means the function will trip only if light and over current conditions are met.
Outputs of the function are Light In, Pressure In, Arc binary input signal status, Zone trip, Zone blocked
and sensor fault signals. Setting parameters are static inputs for the function which are changed only
by user input in the setup phase of the function. Arc protection utilizes total of eight separate setting
groups which can be selected from one common source.
AQ-T216
Instruction manual
Version: 2.00
© Arcteq Relays Ltd
164