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apart from the first one which is permanently displayed in two alarm window lines and the last one
displayed in the last two lines.
2
nd
stage alarm
is an internal control panel mode (indicated by internal acoustic signalling and the
2
ND
STAGE ALARM message in the location of the previously displayed monitoring clock) which, apart
from generating the signals in the control panel, causes the transmission of the fire signal outside
(actuation of declared outputs as outputs to alarming-monitoring devices and actuation of additional
outputs whose actuation depends on the 2
nd
stage alarm occurrence (e.g. external signalling devices
or fire protection devices controlled with relay or potential outputs contacts).
A 2
nd
stage alarm may be preceded with a 1
st
stage alarm or it is generated immediately depending
on the programmed alarming variant for a given zone in the premises or the operation mode set for
the control panel. A 2
nd
stage alarm requires an immediate fire fighting action. During a fire alarm, a
constant acoustic signal is evoked in the control panel (simultaneously with the optical signalling)
which may be dis-actuated by pressing the backlit ACKNOWLEDGEMENT push button.
Pressing the backlit RESET push button results in clearing the fire alarm in the control panel. At least
2
nd
access level is required to reset the fire alarm signalling.
The POLON 4900 control panel enables users to choose (program) one of the 17 alarming variants for
a given zone (marked as 1 ÷ 17). The process of switching a given line element in the addressable
detection line into the alarm mode is verified by the control panel and, in the following sections of
this Manual will be referred to as line element actuation.
The alarming process defined by means of variants 1 ÷ 17 may include all zones in the control panel
programmed according to the programming manual PM. Within one zone, two groups of detectors
marked as group A and group B may be defined. The groups allow creating coincidences
within one zone.
When a fire alarm is generated, an applicable message is printed on the paper tape if the printer has
been provided for operation.
8.1.2 One-stage alarm (variant #1)
Actuation of a fire warning device results in immediate generation of a 2
nd
stage alarm.
This variant is applicable especially for zones of high fire danger.
8.1.3 Two-stage alarm (variant #2)
Actuation of a fire warning device generates a 1
st
stage alarm which is signalled acoustically and
optically during the T1 time allocated for the personnel to react and acknowledge the alarm
(ACKNOWLEDGEMENT push button). If the personnel does not react during the T1 time, a 2
nd
stage
alarm is evoked. Personnel's reaction prolongs the duration of a 1
st
stage alarm with the T2 time
measured from the moment the 1
st
stage alarm is acknowledged. This alarm objective is to
investigate the current fire danger.
After the T2 time elapses, if the personnel has not reset the alarm by accessing the system at the 2
nd
level and pressing the backlit RESET push button, the 2
nd
stage alarm is generated. The T1 and T2
times may be programmed taking into account individual features of the protected facility, in
accordance with the programming manual (PM).
Two-stage alarming switches into one-stage alarming (immediate 2
nd
stage alarm) when the control
panel operates in "PERSONNEL ABSENT” and "DELAYS OFF" mode.
8.1.4 One-stage alarm with single reset (40/60 sec.) of a fire warning device (variant #3)
After a fire warning device is actuated, the control panel waits for 40 seconds for another fire
warning device in the same zone to be actuated. Then the control panel generates a 2
nd
stage alarm.
Otherwise, the control panel resets the device treating its actuation as false and waits for other
