User's Manual

LR-911 2.6H3
AWID PROPRIETARY
Page 10 9/26/2007
the tag. Be sure to elevate the antenna slightly to accommodate sport utility vehicles,
minivans and trucks.
3.4 GENERAL WIRING REQUIREMENTS
All the reader wiring should be continuously shielded. AWID recommends using #22
AWG up to #18 AWG, longer distances and higher current consumption on the power
supply line will require larger gauge wires. Due to system data termination differences,
contact your panel manufacturer for the proper wire sizes to meet their specific
requirements.
TABLE 3.4-1: Data Line’s Wiring Requirement
WIRE SIZE #22 AWG (0.6 mm Dia.) #18 AWG (0.5 mm Dia.)
WIEGAND 500 ft (152 meters) 980 ft (300 meters)
RS-232 50 ft (15 meters) 50 ft (15 meters)
NOTE: WHEN USING AN EXTERNAL POWER SUPPLY, USE A HIGH-QUALITY
POWER SUPPLY THAT MEETS THE CURRENT SPECIFICATION (SECTION
2).
3.5 POWER SUPPLY
For consistent performance, choose a high-efficiency switching power supply with
remote sense and use the voltage sense wire to ensure consistent performance.
Alternatively, use a linear, regulated power supply with sufficient current capacity (see
Section 2, Specifications).
3.6 GROUNDING
Grounding is critical for proper operation of LR-911. When installing the reader, it is
crucial to assure that the earth ground is the best ground available. If you elect to use
the AC main power ground, conduct a test by measuring its resistance relative to a
known good ground, such as a cold water pipe or structural steel that is in direct contact
with the ground. The resistance should be less than 50 ohms. If the AC main power is
found not to provide adequate earth ground, try using a solid connection to a cold water
pipe. Outer shield of cable should not be grounded.
For multiple LR-911 installations, it is critical that all units are connected to the same
grounding system. Using different grounding systems will create secondary current
paths or ground loops that can affect the performance and cause damage to LR-911.
3.7 WIRING DIAGRAMS
See Figure 1 for wiring using Wiegand output to the host panel, Figure 2 for using RS-
232 to the control device, or Figure 3 for a combination of them.