02
NISM/STPA/02
DATE:
PAGE:
No:
ISSUE:
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4
7
ST-P-AS
ANALOGUE-ADDRESSABLE
PHOTOELECTRIC SMOKE SENSOR
INSTRUCTION MANUAL
MARCH 2001
ii)
Introduce a discrete amount of smoke into the
sensor head, using NID-T2 Smoke Test Head or
equivalent. Check that the detector gives an alarm
condition within 15 seconds. Check the LED indicator
on the ST-P-AS sensor illuminates and any remote
indicator LED fitted also illuminates.
iii)
After the sensor has given the alarm condition, reset
the sensor from the control panel. It may be necessary
to allow a short time to elapse before resetting the
detector, to allow any residual smoke from the test, to
disperse.
iv)
Before proceeding to the next detector, ensure that
the sensor previously tested, does not re-operate due to
the presence of residual smoke.
Functional Tests:-
The ST-P-AS may be tested on the TT3 or TT4*
transmission tester, please refer to the instruction
manual for the testers as follows:-
TT3 =
NISM/TT3/01 April 1993
TT4 =
Available early 1998
Cleaning
Figure 1:- 'Exploded' View of ST-P-AS sensor Assembly
i)
Carefully remove the outer cover of the detector by
gently releasing the larger outer cover clip, (see figure 2
below), with a small screwdriver, this clip is visible from
the rear of the ST-P-AS sensor. It is not necessary to
use any excessive force.
Figure 2:- Rear view of ST-P-AS Sensor.
ii)
Remove the chemically-etched insect screen.
iii)
Remove the optic chamber by gently twisting in an
anticlockwise movement
DO NOT DISMANTLE ANY FURTHER
iv)
Examine the optic chamber and the optic's bridge
and check for any dust or dirt which may give cause for
false alarm.
If the sensor is very dirty, damaged or corroded please
return the complete detector to Nittan for service.
v)
If the parts of the sensor are still serviceable, proceed
to clean the outer shield case and plastic outer cover
using both a clean dry brush for dry dust and dirt. A lint-
free cloth moistened with alcohol may be used to remove
sticky deposits from the insect screen, optic chamber
and the optic's bridge.
vi)
Reassemble the sensor in the reverse order. Refit
the plastic outer cover, aligning the LED indicator aper-
ture with the LED indicator. Check alignment of the outer
cover prior to fully pushing home in order to avoid distor-
tion of the insect screen.
Make sure that the three securing clips of the outer
cover are properly aligned and seated. 'Snap fit' the
plastic outer cover to the ST-P-AS body, taking care not
to compress the insect screen.
Ultrasonic Cleaning
This method may be used to good effect for the removal
of contamination from the outer cover, plastic optic
chamber, and chemically etched insect screen, only,
after they have been dismantled from the detector.
However, care must be taken in selection of the solvent
so as not to cause damage to the plastic and insect
Insect screen
Outer cover
Optic Support
PCB
Detector
body
Terminals
Shield Case
Optic chamber
Do not dissasemble
these parts as
this will void
warranty
Large outer
cover clip
