Engineering notes
Floats and level sensors: tanks and drain pans are not one part
A domestic tank, an AHU pan, a soil stack — three products. Contact or analog, NO or NC.
“Water sensor” on a schedule might be a roof-tank float, a 4–20 mA level, or a leak cable under an AHU. Three jobs, three models. A float in a condensate pan is too coarse. A leak cable dropped into a six-metre tank is the wrong article.
Floats: dry contact, NO/NC, cable length, clean or waste water. Analog level: metre range, 4–20 mA, mounting. Pans: a spot head or a short cable. Keep 230 V pump circuits off the digital input.