1)
Calculate the length of the loop cable, bearing in mind the following elements:
a) the number of the loop's windings depends on the loop's perimeter according to the criteria in Table 1.
b) Presence of reinforcements under the road surface reduces the loop's efficiency - the loop must therefore be
increased
c) the loop and power line must consist of a single continuous conductor cable. If interruptions to the loop and
power
placed in a hermetically sealed enclosure.
d) The two loop power cables must be braided to each other a minimum of 20 times per meter of length to avoid
reductions of sensitivity.
TABLE 1.
LOOP PERIMETER
Over 10 metres
from 10 to 6 metres
less than 6 metres
2)
Position the cable in the power line raceway, leaving an end bit to be used for reaching the detector.
3)
Make the necessary windings in the loop groove and once again lay the cable in the power line raceway, braiding
it with the cable already there.
NB.: if the loop power line cables are laid together with other electric cables, they must be adequately shielded. The
shield must be earthed on the detector side only.
4)
Carefully secure the cable inside the groove and seal the loop, making sure that no part of the cable remains
exposed
(Fig.4).
The detector is supplied with a rapid connector complete with connecting wires.
The pins and the relevant wires are described in Fig. 5.
NB.: the detector can be used simultaneously as a pulse generator and as a safety device, by making both the
connections.
PINS 1 – 2 N.C. PRESENCE CONTACT
A N.C. contact is available between pin 1 (white wire) and 2 (pink wire), and is activated when the detector detects the
presence of a metal mass on the loop.
It is usually employed as a safety device.
Contact capacity is 1A at 230 Vac, and the contact makes it possible to command any additional services which are
disabled while the loop is engaged.
PINS 1 – 3 N.O. PRESENCE CONTACT
A N.O. contact is available between pin 1 (white wire) and 3 (yellow wire), and is activated when the detector detects
the presence of a metal mass on the loop.
Contact capacity is 1A at 230 Vac, and the contact makes it possible to command any additional services which are
enabled while the loop is engaged.
PINS 4 – 5 N.O. PULSED CONTACT
Two different pulse activation times can be selected - the times are available on pin 4 (grey) and 5 (grey):
•
when the magnetic loop is engaged;
•
when the magnetic loop is released.
It is usually employed as a pulse generator.
The contact's automatic state-hold time is 250 msec.
PINS 6 – 8 RESET PUSH-BUTTON
We advise you to connect a N.O. RESET push-button between pin 6 (orange wire) and pin 8 (black wire) to be pressed in
the following cases:
•
new setting of the system;
•
new programming of the system;
•
system-restore following an operational fault.
PINS 7 – 8 DECODER POWER SUPPLY
Pin 7 (black wire), -24Vdc, and pin 8 (red wire), +24 Vdc, should be connected to the terminal for externally powering the
24 Vdc accessories of any control equipment.
NB.: observe polarity.
PINS 9 – 10 LOOP POWER SUPPLY
Pins 9 and 10 (purple wires) should be connected to the loop power line.
Make the connection between the wires by welding and insulate them with self-bonding tape or a compression sheath.
2.4. LAYING THE ELECTRICAL CABLE
by two windings.
line cannot be avoided, the relevant connections must be welded and
NUMBER OF WINDINGS
2
3
4
3. ELECTRICAL CONNECTIONS
8