Planning the cable path
Page 38 OmniTrax Product Guide
Road and sidewalk crossings
Sensor cables crossing roads must be protected from potential damaged caused by overhead
traffic driving stones into the cable jacket. For installation under existing roads, you dig trenches
and use a stone dust bedding. Ideally, you can install a section of conduit beneath the road during
its construction. The cable is then pulled through the conduit after the road construction is
complete. The conduit is then sealed at both ends. The same techniques are applied for cable
installation under sidewalks. For an existing sidewalk, the trenches are dug to the edge of the
sidewalk and a hole is bored from side to side at the burial depth. The cable is either pulled
through the hole, or conduit is pulled through the hole and the cable is then pulled through the
conduit. The conduit must be sealed at both ends.
For roadway and sidewalk crossings you can install the sensor cable in PVC conduit as follows:
• PVC conduit, maximum length 7.0 m (23 ft.)
• inside diameter OC2 and SC1 - 19 mm (¾ in.), SC2 - 13 mm (0.5 in.)
• maximum 3 sections of conduit per sensor cable (unless slotted and sand filled)
• conduit sections separated by 1 m (3.3 ft.) minimum
• conduit sealed at both ends to prevent internal water flow
Turning corners
As OmniTrax sensor cables proceed around a corner, there is a slight overshoot in the detection
field in the area of the turn. To prevent a significant detection field overshoot in the area of the turn,
the smallest allowable turn radius for OmniTrax cable is 7 m (23 ft.). A smaller turn radius can
cause a large overshoot which can detect targets outside the prescribed area and thereby result in
nuisance alarms.
Making gradual turns in soft mediums
• Follow a smooth curve around corners with a minimum 7 m (23 ft.) radius to the cable set
centerline.
Note In some cases, road crossings require a cable splice to bypass the
roadway (see Mid-cable obstacles (cable bypasses)
on page 46).
Figure 11: Cable protection for road crossings
conduit under
roadway
maximum conduit
length = 7 m (23 ft.)
conduit sealed
at both ends
To Next Page
Loading...
