Paradox Digiplex DGP-848 Programming Manual page 44

Connections
External Power Supply
Power Units required by devices connected to a power supply do not draw power from the control panel's auxiliary output.
Do not use the same transformer for the control panel and the external power supplies. Modules should
never be installed more than 914m (3000 ft) from the control panel.
Connecting the Combus in Noisy Environments
When installing the combus wires in proximity to high electrical interference such as neon lights, motors, high-voltage wiring,
transformers, or if connecting the combus across separate buildings, you must use shielded cables. Connect the shielded
cable as follows:
Within the Same Building: Strip the outer jacket at one end of the shielded cable to expose the shield and connect the
shield to the control panel ground (not the dialer ground), while leaving the shield at the other end of the cable open (floating).
Across Separate Buildings: Strip the outer jacket at one end of the shielded cable to expose the shield. In the same
building that houses the control panel, connect the exposed shield to a cold water pipe or any other earth ground available,
while leaving the shield at the other end of the cable open (floating). The same configuration applies for any subsequent
building.
Option [7] in section [502] must be enabled
PGM1 becomes control panel input #255
When using ESL smoke detectors with the
CleanMe™ feature, do not connect more
than 20 detectors in parallel.
152m (500ft) from control panel
152m (500ft) from control panel's AUX. output
Therefore this run = max. 273PU
Digiplex DGP-848
*Note: It is recommended that all 2-wire and
4-wire smoke detectors be connected in a
daisy chain configuration.
- 44 - Programming Guide
SINGLE FIRE ZONE CONNECTIONS ONLY
If the ATZ feature is enabled, do not use the
extra input (i.e. in the above example, input
009 cannot be used as a zone).
610m (2000ft) from control panel
152m (500ft) from power supply
Therefore this run = max. 273PU