Why BAS sensor wiring runs two wires instead of one — and what actually gets canceled out when it does.
Run a sensor cable anywhere near a VFD, a motor, or a bank of fluorescent or LED ballasts, and it will pick up electrical interference — that part is unavoidable. What's avoidable is having that interference wreck the reading. Whether it does comes down almost entirely to one design decision made long before the cable was ever pulled: was this signal measured single-ended, against a shared ground reference, or differentially, between two dedicated conductors? That one choice determines whether the noise a long cable run inevitably absorbs ends up in the final number or gets thrown away before anyone sees it.