Maintenance and service
94 / 105
ASD 531, Technical description, T 140 416 en
Continuation:
9.
If it is necessary to clean the sampling pipe as indicated under
Item
6, carry out the following measures (possibly also
according to
Item 10
•
Clean all sampling holes in the entire sampling pipe tube network. Tobacco pipe cleaners can be used for this pur-
pose.
•
If the sampling holes are not accessible, the entire sampling pipe tube network can be blown out from the detector
housing using oil-free compressed air or nitrogen. This is done via the manual ball valve or from the loosened screw-
junction piece (pipe connection) of the last accessory part in the direction of the sampling pipe network.
Warning
Blowing out from inside the smoke sensor chamber (through the fan) can damage the fan and is there-
fore not permitted.
•
Open the accessory parts (water retaining box, filter-box/filter unit, detector boxes) where fitted, and clean with a soft
dry paintbrush. Oil-free compressed air or nitrogen can also be used for cleaning. Replace the filter cartridge in the fil-
ter-box or filter unit. Close all the accessory parts again after cleaning.
•
After cleaning the sampling pipe, re-connect it correctly to the ASD 531.
10.
In applications where dirt is a major issue, it may be necessary to clean the air-flow sensor. For this purpose (see
Sec. 9.4.3) take it out of the holder and clean with a soft, dry brush
Caution: Do not clean or touch the sensor sur-
face with your fingers
. Then re-insert the air-flow sensor as indicated in Sec. 9.4.3
make sure it is correctly seated
inside the holder.
11.
Switch the ASD back on again and wait until the fan has reached its optimal speed (at least 2 min).
12.
Check fault triggering, alarm release and correct alarm transmission to the FACP as described in Sec. 7.6.1. Log the
completed tests in the commissioning protocol.
13.
Read the airflow value again. If the values set out under
6 are still outside the tolerance range, the airflow monitor-
ing will have to be readjusted (initial reset as described in Sec. 7.3.5).
Danger
A new initial reset is not usually necessary after cleaning work on the sampling holes (cleaning restores the
commissioning state). If an initial reset is necessary nonetheless after the work set out under
Item 13
, it may
only
be carried out once it has been ensured that all possible measures for cleaning the sampling pipe have
been carried out (incl. a new filter cartridge).
If an initial reset is carried out with blocked sampling holes, there is the danger that insufficient air samples
or no air samples will be aspirated and hence the ASD 531 can no longer trigger an alarm.
14.
If maintenance or repair work was carried out on the ASD 531 (including the sampling pipe) as a result of servicing
check, a new initial reset may be necessary (see Sec. 7.3.5).
15.
All measurements and tests carried out are to be entered and signed for in the commissioning protocol. The completed
commissioning protocol is to be stored with the ASD. If required, a copy can be made and stored in the system dossier.
16.
After completion of the servicing check, close the detector housing once again.
