Digital Monitoring Products
XR150FC/XR550FC Series Installation Guide
6
WIRE THE PANEL
Wiring Specifications
DMP recommends using 18 or 22 AWG for all LX‑Bus and Keypad Bus connections. The maximum wire distance between
any module and the DMP Keypad Bus or LX‑Bus circuit is 10 feet. To increase the wiring distance, install an auxiliary
power supply, such as a DMP Model 505‑12. Maximum voltage drop between a panel or auxiliary power supply and any
device is 2.0 VDC. If the voltage at any device is less than the required level, add an auxiliary power supply at the end of
the circuit.
To maintain auxiliary power integrity when using 22‑gauge wire on Keypad Bus circuits, do not exceed 500 feet. When
using 18‑gauge wire, do not exceed 1,000 feet. Maximum distance for any bus circuit is 2,500 feet regardless of wire
gauge. Each 2,500 foot bus circuit supports a maximum of 40 LX‑Bus devices. To increase the wire length or to add
devices, install an additional power supply that is listed for Fire Protective Signaling, power limited, and regulated
(12 VDC nominal) with battery backup.
For additional information refer to the LX‑Bus/Keypad Bus Wiring Application Note (LT‑2031) and the 710 Bus Splitter/
Repeater Module Installation Guide (LT‑0310).
Wire the Transformer
The XR150FC/XR550FC Series panel comes with a 16 VAC 56 VA transformer. The 16 VAC transformer must be wired to
a dedicated, unswitched 120 VAC 60 Hz circuit with at least 0.87 Amps available.
Caution:
Never share the Fire Alarm Control Panel circuit with any other equipment. Always ground the panel before
applying power to any devices and use 18 AWG or larger for all power connections.
56 VA
Transformer
The transformer
must be wired to a
dedicated,
unswitched
120 VAC 60 Hz
circuit with at least
0.87A available
GND
Install cover over screw
terminals after
completing connection.
WHITE
BLACK
GREEN/
YELLOW
S
AC
1
2
3
4
+B
AC
–B
Figure 4: Transformer Wiring
