Installation Instructions
Optical Smoke Switch ORS 142
1 Safety instructions
Smoke Switches are used for fire safety and must be
tested for correct operation after installation. If they
are not correctly installed, proper operation cannot
be guaranteed.
Any special national or regional regulations must be
observed.
The sensing chamber of the Smoke Switch must not
be opened.
2 Application
The Optical Smoke Switch ORS 142 detects both
smouldering and open fires with smoke emission.
An additional temperature sensor reacts at a tem-
perature of about 70°C. In the event of an alarm, a
fault, or a power failure, a relay contact opens. The
accessories include a mains unit NG 519 and control
unit NAG 03 for power supply and additional control
tasks (see Section 8 “Ordering data”).
In places with background interference such
as steam, dust, dew formation, or smoke
from a production process, we recommend
use of our Heat Switch TDS 247 (see Section
8 “Ordering data”).
3 Additional functions
In addition, the evaluation electronics of the ORS
142 monitor the sensing chamber of the detector
for slight contamination, heavy contamination, and
faults. The ORS 142 provides visual indication of
its status. By means of a communication interface,
the various operating conditions can be read out
and individually processed using the status indica-
tor RZA 142. An auto drift compensation ensures a
constant difference between the base signal and
the alarm threshold.
4 Mounting and electrical connections
The Smoke Switch ORS 142 must be mounted as
shown in the following illustrations. It must only be
mounted on a horizontal surface.
4.1 Mounting dimensions
Dimensions of Smoke Switch ORS 142 without base:
4.2 Electrical connections
Any commercially-available cable can be used. For
installations in which severe electromagnetic inter-
ference is to be expected, we recommend the use of
screened cables.
Recommended conductor cross-section: 0.6 ... 0.8
mm
Terminal assignment in base for ORS 142:
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1
18 V DC to 28 V DC
2
GND
3
Communication interface
4
Relay contact
5
Relay contact
6
free
Ø 80 mm
33
m
m
