Atest Gaz PW-033-A, User Manual

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3.4 Buzzer – internal acoustic warning /alarm device
The control module contains an internal audible warning/alarm device (buzzer) designed to horn an audible
signal when intervention of the system operator is required, for instance when a gas hazard is detected or
when any part /component of the system reports an error.
The buzzer is activated under the following circumstances:
gas alarms – exceeding of the first, second or third alarm threshold is reported by any of gas
detectors connected to the control unit module,
defects /errors – a defect /error is reported by any of gas detectors connected to the control
module or failure of communication with detectors or a defect of the control module itself.
The activated buzzer produces a modulated audible signal with 0.5 s of sound and 0.5 s of silence.
The buzzer can be switched off (deactivated) for a specific period of time. If so, the buzzer shall horn no
sound, even in case when a triggering signal is active. However, after expiration of the deactivation time the
buzzer is restarted (reactivated). In addition, any new gas alarm 7 or a system defect /error that are reported
during the time when the buzzer is off are capable of the buzzer reactivation. Upon disappearing of the
triggering signal the buzzer goes off.
The buzzer can be deactivated by means of the keypad (see section 3.1.5), DI input (see section 2.3) and
External DI input (see section 2.5). The functionality of temporary deactivation is handled in a different way
for gas alarms and for defect. The possible duration of the buzzer deactivation time are:
for gas alarms: from 1 to 90 minutes,
for defects /errors: from 1 to 168 hours (1 week) or permanent deactivation (the buzzer shall
never be reactivated).
The illustration below presents waveforms for the internal audible signal (under the assumption that the
horn is triggered by a gas alarm and the buzzer is deactivated by means of a keypad button).
7 A new gas alarm is understood as exceeding of the next (higher) alarm threshold on the same detector or appearing of any threshold exceeding
on another detector
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User Manual: POD-002-ENG R03
Figure 15: Behaviour of the internal buzzer – signal waveforms
Button
Buzzer state
Warning 2
Gas
concentration
Warning 1
time
t
DEZ
Gas hazard – the
buzzer goes on
Gas hazard disappeard
– the buzzer goes off
Operator depressed the
button for temporary
deactivation (muting)
New alarm, the buzzer is
tripped again
Operator depressed the
button for temporary
deactivation (muting)
Deactivation (muting) time
– adjustable parameter
The deactivation
(muting) time expired,
the buzzer sound is
restored