ABB REF615 Applications Manual page 169

1MRS756378 D
REF615
Application Manual
The lens sensors can be placed, for example, in the busbar compartment, the breaker
compartment, and the cable compartment of the metal-clad cubicle.
The light detected by the lens sensors is compared to an automatically adjusted
reference level. Light sensor 1, Light sensor 2, and Light sensor 3 inputs have their
own reference levels. When the light exceeds the reference level of one of the inputs,
the light is detected locally. When the light has been detected locally or remotely and,
depending on the operation mode, if one or several phase currents exceed the set
Phase start value limit, or the earth-fault current the set Ground start value limit, the
arc protection stage generates an operation signal. The stage is reset in 30 ms, after
all three-phase currents and the earth-fault current have fallen below the set current
limits.
The light signal output from an arc protection stage FLT_ARC_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 IED
In installations, with limited possibilities to realize signalling between IEDs
protecting incoming and outgoing feeders, or if only the IED 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 IED only is realized by installing
two arc lens sensors connected to the IED 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.
Section 5
Protection functions
163