5.3.25 Arc fault protection (IArc>/I0Arc>; 50Arc/50NArc)
Arc faults occur for a multitude of reasons: e.g. insulation failure, incorrect operation of the protected
device, corrosion, overvoltage, dirt, moisture, incorrect wiring, or even because of aging caused by
electric load. It is important to detect the arc as fast as possible in order to minimize its effects. Using
arc sensors to detect arc faults is much faster than merely measuring currents and voltages. In busbar
protection IEDs with normal protection can be too slow to disconnect arcs within a safe time frame. For
example, it may be necessary to delay operation time for hundreds of milliseconds when setting up an
overcurrent protection relay to control the feeder breakers to achieve selectivity. This delay can be
avoided by using arc protection. The arc protection card has a high-speed output to trip signals faster
as well as to extend the speed of arc protection.
Figure. 5.3.25 - 140. IED equipped with arc protection.
The arc protection card has four (4) sensor channels, and up to three (3) arc point sensors can be
connected to each channel. The sensor channels support Arcteq AQ-01 (light sensing) and
AQ-02 (pressure and light sensing) units. Optionally, the protection function can also be applied with a
phase current or a residual current condition: the function trips only if the light and overcurrent
conditions are met.
The outputs of the function are the following:
• Light In
• Pressure In
• Arc binary input signal status
• Zone trip
• Zone blocked
• Sensor fault signals.
The arc protection function uses a total of eight (8) separate setting groups which can be selected from
one common source.
A
AQ
Q-M255
-M255
Instruction manual
Version: 2.06
258
© Arcteq Relays Ltd
IM00020
Содержание AQ-M255
Страница 1: ...AQ M255 Motor protection IED Instruction manual...
Страница 2: ......
Страница 384: ...Figure 7 4 189 Example block scheme A AQ Q M255 M255 Instruction manual Version 2 06 382 Arcteq Relays Ltd IM00020...
Страница 405: ...Figure 8 14 211 Device installation A AQ Q M255 M255 Instruction manual Version 2 06 Arcteq Relays Ltd IM00020 403...