UTC Fire and Security AirSense Stratos EX Installation Manual page 33

Chapter 3: Installation
Power supply connections
The power supply cable should be of three-core screened type and should be led
through cable gland 1 or 2, leaving about 170 mm of the cable extending from
cable gland 1 or 100 mm from cable gland 2.
Note the orientation of the terminal block. Connect 0 V and +24 VDC to
Caution:
the "0V" and "24V" screw terminals respectively. Connect the earth to the earth
terminal.
Figure 12: Power supply connection
Signal connections
Signal connections should be made using cable suitable for the hazardous area
and compatible cable glands. If RS-485 connection is used, the A+B signals
should ideally be taken through twisted pair cable. The SCN terminal should be
connected to the cable screen if possible; otherwise a third conductor should be
used.
Signals and power should not normally be in the same cable, as electrical noise
can jump between conductors.
Stratos EX Hazardous Area Aspirating Smoke Detection System Installation Manual 27