4
SYMPTOM
POSSIBLE CAUSE
SOLUTION
The POWER LED is not
on.
No power supply voltage on
the input.
Check that the power supply is
correctly wired to the detector.
(PINS 1 and 2)
The DETECT LED flashes
erratically.
There may be a poor
connection in the loop or
loop feeder.
The detector may be
experiencing crosstalk with
the loop of an adjacent
detector.
Check all wiring. Tighten screw
terminals. Check for broken wires.
Try changing frequencies using the
frequency switch. Put the detector
with the larger loop onto low
frequency and the detector with the
smaller loop onto high frequency.
The DETECT LED
randomly stays on.
Faulty loop or loop feeder
wiring.
Movement of the loop in the
ground.
Check the wiring. Tighten screw
terminals. Check for pinched or bent
wires. Is the feeder wire twisted?
Check for cracks in the road surface
near the loop.
The LOOP FAULT LED is
flashing.
The loop inductance is too
small or the loop is short
circuit.
Check that there is no short circuit
on the loop feeder wiring or the loop.
If there is no short circuit then the
inductance is to small and more
turns of wire should be added to the
loop.
The LOOP FAULT LED is
permanently illuminated.
The loop inductance is too
large or the loop is open
circuit.
Check that there is electrical
continuity on the loop. This can be
done using a multimeter on the
ohms range (< 5
Ω
). If the loop
inductance is too large then try
reducing the number of turns.
Wiring Diagram
Diagnostics
11
LOOP1 INPUT
12
9
POWER INPUT
10
8
12-24VAC/DC
0V
RESET
LOOP1
TWISTED
5
4
3
13
LOOP2 INPUT
14
LOOP2
TWISTED
PRESENCE/PULSE
RELAY OUTPUT 1
2
7
6
PRESENCE/PULSE
RELAY OUTPUT 2
