Installation Of Induction Loops - General - Chamberlain LiftMaster Professional BARS1-LE Manual De Instrucciones

6.4 Installation of induction loops – general
The geometry has to be executed depending on unit:
• The loop has to be positioned exactly underneath barrier pole. The barrier pole is positioned on the
side of the barrier casing.
• The monitored area for cars has to be at least 500mm on both sides. For trucks the loops have to
be larger or a second safety loop must be installed.
• Keep loop at a distance of 300 – 400mm from road side.
• Faulty road surface, cracked areas, moving subsoil, loose paving, coarse gravel, metal parts may
be diagnosed as errors and thus disturb the operation. The subsoil must be stable and rigid.
• Avoid iron reinforcements in the road. This may lead to the loop being disturbed. Keep >50cm
distance from iron.
• Heated roads also disturb loop (keep > 100cm distance)
• Garage doors, rolling gates, sliding gates and wing gates disturb the loop's operation if made of
steel. Keep a distance!
• The distance between the loop's control and the loop itself may be max. 15 – 20m. If that is not
possible the diagnosis unit must be installed outside the barrier unit.
• The cable of the loop must be fitted exactly. Coiled cable interferes with analysis.
• The loop's resistance must be checked after installation. It shoul be about 0.8 – 2.0Ohm. The insu
lation resistance against ground must be larger than 1MOhm. The inductance of the loop must be
between 70 - 500μHenry.
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Notes