DMP Electronics XR2500F - Manual (Page 23)

XR2500F Installation Guide Digital Monitoring Products
15
InstallatIon
10.4 Mounting Keypads and Zone Expansion Modules
LCD keypads have removable covers that allow mounting the keypad to a wall or other flat surface using the
screw holes on each corner of the base. Before mounting the base, connect the keypad wire harness leads
to the keypad cable from the panel and to any device wiring run to that location. Then attach the harness to
the pin connector on the PC board, mount the base, and install the keypad cover making sure all of the keys
extend through their respective holes.
For mounting keypads on solid walls, or for applications where conduit is required, use the Model 695 1-1/2”
deep or the Model 696 1/2” deep backboxes.
The DMP 711, 714, 715, 716, and 717 modules are each contained in molded plastic housings with removable
covers. The base provides you with mounting holes for installing the unit to a wall, switch plate, or other
surface.
10.5 Connecting LX-Bus and Keypad Bus Devices
Several factors determine the DMP LX-Bus™ and keypad bus performance characteristics: the wire length and
gauge used, the number of devices connected, and the voltage at each device. When planning an LX-Bus™
and keypad bus installation, keep in mind the following information:
1. DMP recommends using 18 or 22-gauge
unshielded wire for all keypad and LX-Bus circuits. Do not use
twisted pair or shielded wire for LX-Bus and keypad bus data circuits.
2. On keypad bus circuits, to maintain auxiliary power integrity when using 22-gauge wire do not exceed 500
feet. When using 18-gauge wire do not exceed 1,000 feet. 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.
Note: Each panel allows a specific number of supervised keypads. Add additional keypads in the
unsupervised mode. Refer to the panel installation guide for the specific number of supervised keypads
allowed.
3. Maximum distance for any one bus circuit (length of wire) is 2,500 feet regardless of the wire gauge. This
distance can be in the form of one long wire run or multiple branches with all wiring totaling no more
than 2,500 feet. As wire distance from the panel increases, DC voltage on the wire decreases. Maximum
number of LX-Bus devices on the first 2,500 foot circuit is 40 devices.
4. Maximum voltage drop between the 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. When voltage is too low, the devices cannot operate properly.
For additional information refer to the LX-Bus/Keypad Bus Wiring Application Note (LT-2031).
Expansion Interface Cards (Models 481, 462N, 462P, 463G, and 472)
The LX-Bus provided on these cards requires only a 4-wire cable between the card and any devices
connected to the bus. You can connect devices (zone or output expansion modules) together on the same
cable or provide separate runs back to the card. Each LX-Bus provides up to 100 zones or outputs.
Note: Do not use twisted pair or shielded wire when connecting an LX-Bus or keypad bus.