Keri Systems SB-293 - Manual (Page 36)

Technical Reference Manual – PXL-250 and SB-293 Keri Systems, Inc.
Page 36 P/N: 01836-004 Revision 5.5
8.2.1.2 Fail-Secure Lock
Fail-secure means that if the power should fail at a door (perhaps due to a power
outage or equipment failure), the door will automatically lock and not allow entrance
but will continue to allow egress. Power is required to unlock the door. A fail-secure
door ensures a secured area remains secure regardless of the situation.
A typical fail-secure application may use a door strike. In this application, the
controller energizes the lock relay, causing the lock relay to change its state. In its new
state the normally open circuit is closed activating the release mechanism for the door
strike on the door to be opened. Refer to Figure 9-11 on page 53 (for the PXL-250) and
Figure 10-4 on page 74 (for the SB-293) for possible fail secure Lock Relay wiring
diagram.
8.2.2 Alarm Out Relay
Activating an audio (or a silent) alarm is controlled by the Form C alarm out relay. An
alarm condition causes the controller to energize the alarm out relay, causing the alarm
out relay to change its state. In its new state the normally open circuit is closed
activating the alarm. Refer to Figure 9-9 on page 51 (for the PXL-250) and Figure 10-
5 on page 76 (for the SB-293) for possible Alarm Out Relay wiring diagram.
8.2.3 Door Held Open Relay
The Doors program allows the Alarm Out Relay to be configured for annunciating
both Door Forced and Door Held Open alarms or for annunciating only Door Forced
alarms. If the Alarm Out Relay is configured to only annunciate Door Forced alarms,
the Door Held Open condition is then configured for either annunciation on a separate
output relay or for no annunciation at all. If the Door Held Open Relay is configured to
be annunciated on a separate output relay (distinguishing it from a door forced alarm)
programming in the Doors program routes door held open alarms to designated
general-purpose output relays on the SB-293: TB-10, Pins 4, 5, and 6 for the A-Door
and TB-10, Pins 1, 2, and 3 for the B-Door.
A door held open condition causes the controller to energize the Door Held Open
relay, causing the relay to change its state. In its new state the normally open circuit is
closed activating the alarm. Refer to Figure 10-6 on page 78 and Figure 10-7 on
page 79 for a possible Door Held Open alarm relay wiring diagram.