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Motion sensors need 4 wires (two for DC power). Better to use 6 or 8
conductor for long runs so wires can be doubled up for DC power (DC Voltage
drop). Motion sensors are usually mounted near the ceiling in a corner, and
usually in living room and/or hallway.

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What if you had a 15 feet ceiling? Most motions are to be mounted 7.5 feet
from the floor.