Chapter 6: DPX Series
66
How a Cable Water Sensor Works
The cable water sensor uses
black wires on the water rope to detect the
water. When there is water between two black wires, it causes current
loop back to trigger the alarm on the water sensor.
Mechanical information about black wires:
The distance between two black wires is about 0.3 in.
The distance from the black wire to the cable surface is about 0.05
in.
Water detection requirements:
The water spot should be at least 0.5" wide so that two black wires
are in the water at the same time. Otherwise, the water cannot cause
current loop back on the water sensor to trigger the alarm.
If the water spot is about 1" wide, the water sensor should detect it at
any location of the water rope.
The
thickness of the water spot should be at least 0.1" because there
is some gap between any black wire and the cable surface.
This is why the cable water sensor does NOT work well with the
concrete floor but works fine with ceramic tiles. The concrete floor
absorbs the water quickly so it needs more water on the concrete
floor to trigger the alarm.
