Wallace Perimeter Security FOLDSMART, Руководство по установке и обслуживанию

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wallaceperimetersecurity.com
Phone: 866.300.1110
INSTALLING VEHICLE DETECTORS AND LOOPS
9� This guide is written from a design perspective, but installation workmanship practices are equally
important to ensure proper operation and long loop life. The best way to ensure a quality installation
is to employ a professional installer experienced with detector loops. A few important practices are:
• The slot in the surface of the road should be cut ¼-inch wide x 1½-inch deep (6.3 x 38.1mm).
• The corners of the cut must be at an angle or core drilled to relieve stress on the wires.
• After the wire is installed, the slot must be completely backfilled with a non-hardening sealer. If
the loop wires are able to move in the slot after the sealer has set, the detector may give false
calls.
Figure 23 . Loop Sealant Application
Detector Logic
Wallace Perimeter Security recommends that vehicle detectors be used for free open and obstruction
sensing logic only. Because of their slower speeds, closing logic is a poor choice for security gate systems.
Since there are several ways that the gate may be left standing open and because there is a loss of safety,
our circuit has not been designed to accommodate “detect to close” logic.
Loop Diagnostics
The following tests cannot guarantee a functioning loop, but failure of either test means that the loop is
definitely suspect, even though it may still be functioning at the time.
1� Test the resistance of the loop and lead-in wire. It should not exceed 4 ohms.
2� Test the resistance between the loop and earth ground with a 500V Megohmmeter. It should be
100 Megohms or more. Loops may function at less than 100 Megohms but will not be reliable
(e.g. , when the ground is wet from rainfall). Low resistance indicates broken or moisture - saturated
insulation. This is common if inappropriate wire insulation has been used.
Schematic for FoldSmart Loop Layout is shown in Figure 24 .