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SECTION 1 INTRODUCTION
The LN1000 annunciator is an intrinsically safe process alarm system certified for installation
in Zones 0, 1, 2 IIB and IIC hazardous areas.
The annunciator is a totally unique product which provides an ideal solution to alarm
monitoring problems where an operator needs additional information on the plant status and
control over external parts of the plant.
Being certified to Ex ia means there are no restrictions with regard to maintenance whilst the
power is applied as there are with Ex d, Ex p or Ex N equipment.
The annunciator system consists of three parts; the Chassis (12 way or 32 way), the
Sequence Card and the Alarm Card.
Each system will consist of the chassis complete with the Sequence Card, which controls the
common functions, and as many Alarm Cards as necessary to cover all the alarm points to
be monitored.
The power for the annunciator is supplied from the safe area through a single certified
isolating interface, which avoids the requirement for a high integrity earth. This single IS
interface is sufficient to drive up to 32 alarm channels.
The annunciator functions in a similar manner to a conventional, safe area annunciator, but
because of the limited power available the information is displayed using a combination of
high efficiency LED's and LCD’s in the place of incandescent lamps.
The system is fully programmable, via DIL switches, for a range of commonly used functions
and features. The alarm sequences are based on the sequences listed in the ISA publication
"Annunciator Sequences and Specifications" S18.1 -1979.
The operator can respond to alarms using either integral or remote pushbuttons.
The standard system is panel mounting to allow customers to incorporate it into their control
systems but if a stand-alone alarm system is required RTK can offer a wall mounting version
which is fully self contained in a stainless steel enclosure.
The LN1000 annunciator is available with a range of complementary products, manufactured
by RTK; these will allow signal transfer between hazardous to safe areas (DA-149 IS
Relays), provide higher volume audibles (DB-5 and DB-7 IS Sounders) and flashing beacons
(DA-135 IS LED Beacon).
With this range of products it is very easy to design and configure a comprehensive alarm
monitoring package for any hazardous area.