Terminal Board; Annunciator Strip - Secutron MR-2900 Installation Manual

1.6 Terminal Board

Field connections are terminated on the MR-2936 Terminal Board, which in addition to terminal blocks
contains a portion of the circuitry for output circuits and relays. The Terminal Board includes connections
for 24 input circuits, 8 supervised polarity reversing bell circuits, 4 general purpose Form "C" relays, 3
system Form "C" relays and 2 auxiliary power outputs. There is a five-pin terminal block on the bottom of
the Terminal Board for connection of the optional factory installed printer.
There are two versions of the Terminal Board. The MR-2926 Terminal Board has 8 Class B bells circuits.
The MR-2925 Terminal Board has 4 Class A bell circuits. The two versions are identical otherwise.The
MR-2936 supports 8 Class B bell circuits and 8 Class A bell circuits when a MR-2937 Class A Convertor
Board is installed.
The bell circuits are rated at 1.5 A @ 24 VDC. They are power-limited and protected with solid state fuses.
Note: Maximum system loading and stand-by battery power must be considered when determining
actual bell loading.
A 10 K end-of-line resistor, EOL-103, is required for supervision. Bell circuits are supervised for open, short
and ground fault conditions. The panel activates bell circuits in two modes: Evacuation, which activates the
bells continuously or with the temporal pattern as specified in ANSI S3.41 and ISO 8201 Audible
Emergency Evacuation Signal; Alert, which activates the bells in a repeated 12 s on and 3 s off.
The general purpose Form "C" relay operation is program defined. The relays have a power factor of .35
and are rated at 0.6A @ 30VAC / 2.0A @ 30VDC. The system defined Form "C" relays are for Alarm,
Supervisory and Trouble indication. These relays have a power factor of .35 and are rated 1.0A @ 24VDC
/ 0.5A @ 30VAC. The Trouble relay is normally energized so that loss of both AC power and battery power
is indicated. The N.O. and N.C. markings on the Trouble relay refer to this energized state.
The operation of the general purpose relays and bell circuits is totally program defined. It is possible to
program the activation of circuits to any zone, group of zones, device, group of devices and to further
inhibit the operation for a specifiable period of time. Any relays not programmed for use in either the
database or LCD menu are available for auxiliary power reset, i.e. the relay toggles for a programmable
time when the Reset key is pressed provided the programmed time is a value other than zero.
The auxiliary power outputs provide 24 VDC @ 135 mA each. They are supervised for shorts only. Any
load attached to the auxiliary power outputs have to be considered when calculating stand-by battery size.

1.7 Annunciator Strip

The Annunciator Board (MR-2902) contains 24 sets of zone indicating LEDs. Individual LEDs are provided
to display alarm, supervisory and trouble conditions by zone. The LED functions, from the left, are: Alarm
(red), Supervisory (amber or yellow) and Trouble (yellow). The LEDs flash on status change and go to
steady on acknowledge. The trouble LEDs turn on for both open circuit and ground fault with the specific
fault indicated on the LCD.
MR-2900 Installation Manual
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