RTK Series UC625 Annunciator
9
Introduction
The RTK UC625 Series Alarm Annunciator system is designed to give LED indication of an alarm
condition, where a high degree of reliability and flexibility is required.
Each system comprises a compact cabinet, removable legend plate, universal Alarm Cards and a
Supply/Pushbutton/Relay (SPR) Card which gives maximum annunciator density whilst maintaining a
practical legend area and neat front panel appearance.
DIL switches, situated on each of the Alarm Cards permit easy selection of annunciator sequences as
listed in the ISA Publication “Alarm Sequences and Specifications S18.1 – 1979 (R1985)”.
As the system is fully field-programmable on a per pair of alarm basis, the operating specification, of
both alarm sequence and function, can be changed during commissioning, or at a later date after the
equipment is installed. This means that stocking requirements may be minimised, since all annunciator
cards are interchangeable.
Reliability of operation is increased over conventional annunciators by the use of application specific
integrated circuits (ASIC's), which are capable of complete system control. When the annunciator is
initially switched on, control is arbitrarily allocated to any one of the ASIC's on any of the Alarm Cards,
hence the annunciator requires no control or master module, failure of which could jeopardise the
whole system.
If the Alarm Card is removed or an ASIC goes faulty then control is randomly allocated to another
ASIC on another Alarm Card, hence the worst fault that could normally occur is the loss of one card.
The use of ASIC's also results in a very low component count, again improving system reliability.
The UC625 features an integral, dual power supply capable of accepting a supply voltage from either
88-265VAC OR 88-360VDC which allows the user to connect the unit directly to a main and aux
supply to provide redundant operation.
As an option, if specified at time of order, the second supply voltage can be manufactured to allow
direct operation from an Aux.24VDC Supply Voltage in the range 19 to 31VDC.
As standard an internally generated 24VDC is used as a signal supply voltage, which is used for
distribution to the associated field contacts. The 24VDC signal supply is designed to be present if
either the primary or secondary supply is available to ensure 100% redundancy.
Note:- When using the direct powered input options the signal supply voltage is derived from outside
the unit, by others, and redundancy is therefore dependent on the signal supply voltage being
available at all times.
On systems supplied after January 1
st
2008 the signal supply voltage is provided with a monitor relay.
Two alarm channels are dedicated to monitor the dual supply Inputs and alert the operator if there is a
loss or failure of either.
Accessibility for servicing is excellent, being accomplished from the front of the panel with only a
screwdriver required to access the alarm or Supply / Pushbutton / Relay card.
