Transcript
Loop Installation The vehicle detection characteristics of the inductive loop detector are greatly influenced by the size of the inductive loop and its proximity to moving metal objects such as gates. Vehicles such as small motorcycles and high-bed trucks will be detected reliably when the inductive loop is sized correctly. If the loop is placed too close to a moving metal gate, the detector may detect the gate. The diagram below illustrates the dimensions that influence detection. SLIDE GATE
General Rules 1. The detection height for a loop is 2/3rds the shortest length (A or B) of the loop wire. For example: when the shortest length of loop wire = 6 ft, detection height = 4 ft. 2. As length A increases, the distance C must increase. A loop wire with length A = 6 ft should have distance C = 3 ft. Where A = 9 ft, C = 4 ft; where A = 12 ft, C = 4.5 ft; where A = 15 ft, C = 5ft; where A = 18 ft, C = 5.5 ft; where A = 21 ft, C = 6 ft. 3. For reliable detection of small motorcycles, lengths A and B should not exceed 6 ft.
C A
A = Loop dimension parallel to the gate B = Loop dimension perpendicular to the gate
B
C = Distance of the loop from the gate
Recommended Loop Wire
Reno A & E LW – 120 for 1/8” slots Reno A & E LW – 116 or LW-116-S for 1/4” slots
Loop Installation Saw Cut Type 1
Mark the loop layout on the pavement. Remove sharp inside corners that can damage the loop wire insulation.
2
Set the saw to cut to a depth (typically 2 to 2.5 inches) that ensures a minimum of 1inch from the top of the wire to the pavement surface. The saw cut width should be larger than the wire diameter to avoid damage to the wire insulation when it is placed in the saw slot. Cut the loop and feeder slots. Remove all debris from the saw slot with compressed air. Check that the bottom of the slot is a uniform depth.
3
It is highly recommended that a continuous length of wire be used to form the loop and feeder to the detector. Recommended loop wire is Reno A&E LW-120 for 1/8-inch slots and Reno A&E LW-116 or LW-116-S for 1/4-inch slots. Use a wood stick or roller to move the wire to the bottom of the saw slot (do not use sharp objects). Wrap the wire in the loop-saw-cut until the desired number of turns is reached. Each turn of wire must lay flat on top of the previous turn.
4
The wire must be twisted together a minimum of 6 twists per foot from the end of the saw cut to the detector. The wire must be held firmly in the slot with 1-inch pieces of backer rod every 1 to 2 feet. This prevents the wire from floating when the loop sealant is applied. Apply the sealant. The sealant selected should have good adherance properties with simular contraction and expansion characteristics to that of the pavement material.
5 6
Loop Perimeter (feet) Number of Turns 10 - 16 17 - 31 32 - 100 100 - up
4 3 2 1
ROAD SURFACE 6 5
1 1/8" to 1/4" SAW SLOT
3
THE WIRE IS CONTINUOUSLY WOUND IN THE LOOP SAW SLOT FOR THE REQUIRED NUMBER OF TURNS (2 turns shown) turn 2
2
SAW SLOT
SEALANT BACKER ROD 1" piece
REMOVE SHARP INSIDE CORNERS
MIN 1"
O P E R A T I N G
I N S T R U C T I O N S
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Model BX-LP Series Firmware Revision BXLP01
LOW-POWER LOOP DETECTOR Model BX-LP
RELAY OUTPUTS
Output: Form C contacts. Input Power: 9 to 15 VDC Current Draw: From 1.1 mA to 5.0 mA in the NO DETECT state. Less than 40 mA when in the DETECT state.
Model BX-LP-SS
SOLID-STATE OUTPUTS
Output: Open drain FET sourced to DC common. Rated for a continuous current of 3.9 A @ 10 VDC. Input Power: 8 to 26 VDC Current Draw: From 1.1 mA to 5.0 mA with outputs ON or OFF. The current draw is dependent on the sensitivity setting (see Current Draw at each Sensitivity Level below). Both the relay and solid state versions consume from 1.1 mA to 5.0 mA of current when the outputs are OFF. The current draw in the NO DETECT state is dependent on the sensitivity setting (see the chart below: Current Draw at each Sensitivity Level). The relay version consumes about 30 mA of current when activated during the DETECT or Fail-Safe output state. The solid-state version draws from 1.1 mA to 5.0 mA regardless of the output state.
Output
FAIL-SAFE during Loop Failure Output ON Output OFF
FAIL-SECURE during Loop Failure Output OFF Output OFF
END OF SAW CUT
SWITCH POSITION
Current Draw No Detect
SWITCH POSITION
Current Draw No Detect
0 1 2 3
1.1 mA 1.3 mA 1.5 mA 2.5 mA
4 5 6 7
3.0 mA 3.5 mA 3.5 mA 5.0 mA
0 = Lowest, 3 = Normal, 7 = Highest Use the lowest sensitivity setting that detects the desired vehicles. File: Model BX-LP Operating Instructions
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F O R
CURRENT DRAW AT EACH SENSITIVITY LEVEL
TO DETECTOR FEEDER SLOT
Telephone: (775) 826-2020 Facsimile: (775) 826-9191 Internet: www.renoae.com E-mail:
[email protected]
A B
LOOP WIRE
THE WIRES MUST BE TWISTED TOGETHER 6 TWISTS PER FOOT F R OM T H E EN D O F THE SAW CUT TO THE DETECTOR
turn 1
Reno A & E 4655 Aircenter Circle Reno, Nevada 89502 U.S.A.
6/14/99
