Ice NP900 Series, Инструкция по применению

Страница: 147 / 504

Application Guide - NP900 Series 147 (504
)
A996A
To set the zones for the NP900 models sensor channels start by enabling the protected
zones which in this case are Zones 1 and 2. Then define which sensor channels are
sensing which zones. In this case sensor channels S1 and S2 are protecting Zone 1.
Enable Zone 1 Light 1 and Zone 1 Light 2. Sensor channel S3 deals with Zone 2. Enable
Zone 2 Light 3. High speed output contacts HSO1 and HSO2 have been set to send
overcurrent and master trip signals to the NP900 arc protection relays.
If any of the channels has pressure sensing sensor included do the enable pressure in
same way as with normal light sensor. If phase overcurrent or residual overcurrent current
is needed in tripping decision those can be enabled in the same way as enabling the light
sensors in the zone. When a current channel is enabled measured current needs to be
over the set current limit in addition to light sensing.
3.2.12.2 M
EASURED INPUT VALUES
Arc protection uses sample based per phase measurement. If required number of
samples is found over the setting limit current condition activates. It is possible to use
either phase currents or residual current in the tripping decision.
3.2.12.3 P
ICK
-
UP CHARACTERISTICS
Pick-up of each zone of ARC function is controlled by phase current pick-up setting,
residual current pick-up setting and the sensor channels (depending on which of these are
activated in the zone).