ABB RELION 620 Series Technical Manual page 558

Section 5
Protection-related functions
552
The light signal output from an arc protection stage ARC_FLT_DET is activated
immediately in the detection of light in all situations. A station-wide arc protection is
realized by routing the light signal output to an output contact connected to a binary input
of another relay, or by routing the light signal output through the communication to an
input of another relay.
It is possible to block the tripping and the light signal output of the arc protection stage
with a binary input or a signal from another function block.
Cover unused inputs with dust caps.
Arc protection with one protection relay
In installations, with limited possibilities to realize signalling between protection relays
protecting incoming and outgoing feeders, or if only the protection relay for the incoming
feeder is to be exchanged, an arc protection with a lower protective level can be achieved
with one protection relay. An arc protection with one protection relay only is realized by
installing two arc lens sensors connected to the protection relay protecting the incoming
feeder to detect an arc on the busbar. In arc detection, the arc protection stage trips the
circuit breaker of the incoming feeder. The maximum recommended installation distance
between the two lens sensors in the busbar area is six meters and the maximum distance
from a lens sensor to the end of the busbar is three meters.
1MAC504801-IB E
620 series ANSI
Technical Manual