Overview, Continued
A-5
For systems intended for Halon 1301(NFPA 12A), Halon 1211 (NFPA12B), or clean agent
(NFPA 2001) release, a pre-discharge NAC must be configured to warn building of the impending
discharge. The setting of the release timer selects the duration of the pre-discharge signal.
Compliance with ADA requires Audible and Visible notification.
Activation of a manual release switch is indicated with the red “Manual Release” LED. Upon
activation of the Manual Release switch, the system will activate the applicable releasing circuits
when the Manual Release timer expires. The system will also activate the applicable releasing
circuits upon expiration of a previously active automatic release timer, if the remaining time on the
automatic release timer is less than the programmed Manual Release timer. Note that setting the
manual release timer to “zero” will result in an immediate release.
If a delay timer is used, the NAC2’s cadence is a 120 BPM code while the timer counts down.
When the timer expires, NAC2 horns change from pulsing to ON Steady.
Note: When the NAC2 horns pulse at 120 BPM, agent release is imminent.
An operator can prevent the release of the suppression agent by pressing the abort switch at any
time between when the automatic releasing sequence starts and the solenoid is activated. It is
critical that all operators and building facilities’ personnel understand the following about the
abort switch.
Manual release stations override the abort switch. In other words, if a manual release station
is activated while the abort switch is held in, agent release occurs.
No agent release occurs while the abort switch is held in.
The abort switch has no effect on an activated releasing, preaction, or deluge system (i.e., if
the system is releasing agent or water, pressing the switch will not stop the release).
For IRI Abort, the abort switch must be pressed and held before the second alarm activation
occurs to prevent release.
When the abort switch is released, one of the following occurs:
If the alarm conditions clear and a system reset occurs before the switch is released, no
agent release occurs.
If the alarm conditions are not clear and the delay timer is still running, no agent release
occurs until the timer expires.
If the alarm conditions are not clear and the delay timer has expired, agent release
occurs.
Continued on next page
Overview, Continued
Manual Release
Switch
Abort Switch
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