B:PREPARING THE SITE

Figure 7: Loop Diagrams

For saw-cut installations, observe the methods recommended in Figure 7, above. The saw-cut must be to a depth of 1.5", clean and with no sharp corners. After placing the wires, it is essential that the wires be held tightly in place by a foam backing prior to pouring the sealant. THIS IS ESPECIALLY IMPORTANT WHEN FREEZING IS LIKELY. No voids should exist that will permit the collection of water that might freeze and push the loop wires out of the slot. The sealant used should not be hard setting and should be suitable for pavement material.

THE WIRE USED FOR THE LOOPS MUST BE HEAT AND WATER RESISTANT, CROSS-LINK POLYETHYLENE INSULATED. TYPE XLPE IS BEST. RHW IS O.K. DO NOT USE ANY PVC INSULATED WIRE. (PVC insulation will absorb moisture that may affect Detector operation.) WIRE SIZE SHOULD BE #16 GA. STRANDED OR LARGER.

VEHICLE DETECTOR LOOP BLANKING FOR SWING GATES

The inside loop for a swing gate installation must be located at least 4 feet outside of the arc of the gate. If it is not, the Vehicle Detector

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may detect the gate as it moves over the loop and cause the Gate to reopen. If the gate is large and a single leaf, the arc usually requires that the loop be a considerable distance from the closed gate position. This may not be an effective position for the loop. In this case, a “blanking” or “shadow” loop may be used.

WHEN A SHADOW LOOP IS NECESSARY, THE HDSWG 1000 MUST BE ORDERED WITH A SPECIAL DOUBLE POLE LIMIT SWITCH FOR THE OPEN LIMIT SWITCH. The Vehicle Detector relay control signal must be routed through the normally open contacts of the second switch contacts of the Double Pole Open Limit Switch. When the gate is in the fully open position, this contact will close the circuit of the Vehicle Detector to the HDSWG 1000 and prevent the gate from closing when a vehicle is over the Shadow Loop. When the gate is closing or opening, this contact of the Limit Switch is open and the Vehicle Detector signal path is broken.

ELECTRICAL POWER REQUIREMENTS

The HDSWG 1000 can be ordered for 115 Volts AC (VAC) or 230 VAC operation. Which voltage HDSWG 1000 to order depends solely on the distance from the electrical service to the operator and the wire size desired to be used. The AWG wire size for the

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Allstar Products Group HDSWG 1000 Vehicle Detector Loop Blanking for Swing Gates, Electrical Power Requirements