System Wiring; Earth Grounding; System Bus Connection - GE Alliance AL-2017 Installation Manual

System Wiring

All panel wiring should be kept well away from other wiring, avoiding parallel wire runs with other wires. Where parallel wires are
unavoidable, keep wires a minimum of 2 inches apart, or in EMT. We recommend that Alliance system components that use direct wire
transformers be wired into a dedicated circuit breaker and those that use plug-in transformers be plugged into an unswitched outlet.
Earth ground
WARNING Each control panel or device which mounts in a metal enclosure, must have its enclosure connected to earth
ground. Correct earth grounding procedure must be followed.
Earth grounding one enclosure containing several devices
All devices designed for the system have chassis ground connections via metal studs to the metal enclosure. Take care that these metal
studs make good connection to the enclosure (beware of paint). The earth connections of every piece of equipment in the system can be
used for connecting the shielding of shielded cables. If a device, such as a keypad, is placed in a plastic enclosure the earth lug of this
device does not have to be connected.
Earth grounding panels in a single building
If several enclosures or devices are connected to earth ground in one building, the safety earth ground of this building has to be checked by
a licensed contractor.
Earth grounding panels in multiple buildings
If the wiring extends to separated buildings, more than one common earth ground system will be used. Use isolater/repeaters to isolate the
system bus. In this way the system is protected against variations in earth potential.

System bus connection

The system bus (COMMS) is used to connect data gathering panels (DGP) to provide extra zones, and remote arming stations (RAS) to the
Alliance system control panel. Remote devices can be up to 5,000 feet (1.5 km) from an Alliance system control panel. DGP and RAS
devices must be connected via a 2-pair twisted, shielded data cable from the system bus connection (Belden 8723 is recommended). The
shield of the data cable should be connected to earth at the Alliance system control panel and should be left disconnected at any other end.
We recommend that where the distance between the arming station and the nearest device is more than 328 feet (100 meters), a separate
power supply be used to power the arming station. To power the arming station, do not connect '+' from the system bus. Connect '+' of
the local power supply to '+' on the arming station and connect 0 volts from the power supply and 0 volts from the system bus to the
arming station terminal marked '-'.
Note: The first and last devices on the system bus must be terminated. All other devices on the system bus must not
be terminated.
Figure 4. System bus connection
D-D+OV
DGP
AL-2017/AL-3017 Installation Manual
System bus
12V Connection
D-D+0V+12
RAS
D-D+0V+12
Control panel
5