Installation guide

XR500 Series Installation Guide Digital Monitoring Products

InstallatIon

4.3 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specicnumberofsupervisedkeypads.Addadditionalkeypadsinthe

unsupervisedmode.Refertothepanelinstallationguideforthespecic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rst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.

Primary Power Supply

5.1 AC Terminals 1 and 2

Connect the transformer wires to terminals 1 and 2 on the panel. Use no more than 70 ft. of 16 gauge or 40 ft. of 18

gauge wire between the transformer and the XR500 Series.

Always ground the panel before applying power to any devices: The XR500 Series must be properly

grounded before connecting any devices or applying power to the panel. Proper grounding protects

against Electrostatic Discharge (ESD) that can damage system components. See the Earth ground section.

5.2 Transformer Types

Use Model 327 (16.5 VAC 50 VA) plug-in or Model 322 or 323 (16 VAC 56 VA) wire-in transformer. Use Model 322 or

323 (16 VAC 56 VA) wire-in transformer when required by the Authority Having Jurisdiction (AHJ).

The transformer must be connected to an unswitched 120 VAC 60 Hz electrical outlet with at least .87A of

available current. Never share the transformer output with any other equipment.