Controlled Products Systems Group 222EX43 - Manual (Page 56)

38 © 2012 Installation and Reference Manual D0119 Rev. J
Section 5
—Detector Loop Installation, continued
9. Follow this guide for the correct number of turns in the loop;
12 to 20 sq. ft = 5 turns (3.6 to 6 sq. meters)
20 to 60 sq. ft. = 4 turns (6 to 18 sq. meters)
60 to 240 sq. ft. = 3 turns (18 to 73 sq. meters)
10. This guide is written from a design perspective, but installation workmanship practices are equally important to insure
proper operation and long loop life. The best way to insure a quality installation is to employ a professional installer
experienced with detector loops. A few important practices are:

The slot in the surface should be cut ¼ " wide x 1½" deep (6.3mm x 38mm).

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.
NOTE: If the loop wires are able to move in the slot after the sealer has set, the detector may give false calls.
Detector Logic
HySecurity recommends that vehicle detectors be used for free open and obstruction sensing logic only. The exception is
in parking applications with our StrongArm operator (HTG 320) where detectors may be also used to close the gate. In
applications employing our swing, vertical lift, or sliding gate operators, closing logic cannot be used. 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, o
ur 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.
Test #1:
Resistance of the loop and lead-in wire should not exceed 4.0 Ohms.
Test #2:
The resistance to earth, as measured with a 500V “Megger”, should be 100 Megohms or more. Loops may function at 10
Megohms or less 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.
See also Detector and Loop Fault Diagnostics on page 43 for additional tests that may be performed with HySecurity
HY-5A detector modules.