Honeywell Galaxy 3-48C Installation Instruction

Page of 90
Galaxy 3 Series Installation Manual
2-12
RS485 Recommendations
6.
There must only be a single AB pair of wires in each of the cables.
7.
The minimum voltage level is 10.5 Vd.c. with 12.5 Vd.c. being the recommended working minimum.
8.
The power supply in the Galaxy control panel and remote power supplies must not be connected
in parallel.
9.
The 0 V of all remote power supplies should be connected in common to the 0 V of the Galaxy
control panel.
10.
Ensure that any extension loudspeakers are not wired in the same cable as an AB pair of wires.
11.
Where possible, ensure that the AB cable is at least 30 centimetres away from any other cables.
12.
Where possible, ensure that the AB  cable does not run parallel to other cables for extended
distances (maximum 5 metres).
Figure 2-10. Connection of cable screen using P-Clip
A
B
AB connectors
RS 485 cable
data line
data line
P-clip
Cable screen
Nut
P-clip
Earthing pillar
(threaded)