Interlogix NXG-4, Инструкция по установке и программированию, Страница: 30 / 170

18 xGen Lite Installation and Programming Guide
(*) Refer to the detector installation manual for EOL values and wiring instructions.
Power Requirements
The xGenLite intrusion panel family is designed to be used with a 16 VAC 1.5 A,
35 or 40 VA transformer which is included with xGenLite panel kits. This
transformer includes a 500 mA 250 VAC fast blow replaceable fuse on the
terminal block. If more current is required, add NXG-320 Smart Bus Power
Supplies.
Cable Requirements
The system RS-485 communication bus is used to connect keypads and in- and
output expanders to the xGenLite intrusion panel.
• Belden 7201A, 3107A or 9842 cable is recommended.
Cable must provide:
>= 13 twists per metre or >= 4 twists per foot,
<= 52 pF per metre or <= 16 pF per foot,
and characteristic impedance 100 to 120
Ω.
• 800 m total cable run on system.
• Max. 800 m from remote device to xGenLite control panel.
• Max. 32 devices plus panel.
• Max. 16 keypads, as part of the 32 device limit.
Grounding
All devices designed for the system have earth connections via metal studs to
the metal housing. Make sure that these metal studs make good connection to
the housing (beware of paint). The earth connections of every piece of equipment
in the system can be used for connecting the screen of shielded cables.
If a device is placed in a plastic housing the earth lug of the device does not have
to be connected.
In one building several cabinets or devices are earthed to a safety ground. The
safety ground for the building must be checked by a licensed contractor.
Shielding
The shielding of all shielded cables used in the system should only be connected
at one side to one common earthing point in a building. If a shielded LAN cable is
routed via more than one plastic device the shielding from incoming and outgoing
cable must be connected.