Mystery Gate Operation

© 2002 Door & Access Systems
Publish Date: Summer 2002
Author: Tom Wadsworth
Page 46

Technical Tip
Mystery Gate Operation

What is happening when an automated vehicular gate begins operating for no apparent reason?

The problem may be the wrong type of wire used to connect a loop detector to a gate operator. Joe Rozgonyi, president of EMX Industries, says that using the wrong wire may lead to a loop detector falsely detecting a vehicle.

Rozgonyi recommends using 16-gauge stranded tinned copper wire with cross-linked polyethylene (XLPE) insulation rated for 600 volts. He says THHN wire is commonly used, but it is intended for raceways, conduit, and tubing, but not in asphalt and concrete pavements.

THHN wire's thin nylon coating, he says, may be vulnerable to moisture due to damage during installation, or due to erosion caused by chemicals in pavements. “False vehicle detections can occur from a combination of high humidity and a damaged or eroded THHN wire,” he adds.

Proper installation and operation of vehicle detectors, including connection wiring, is essential not only for safety and property protection but to reduce or eliminate unnecessary customer service calls.