What this sensor is and why it fits a sourcing line
The XS630B1MBU20 is a 30 mm shielded tubular inductive proximity sensor from the Telemecanique OsiSense XS series, with a normally closed (NC) output and a 3-pin 1/2 inch-20 UNF male connector. It runs on universal supply 24 to 240 VAC/VDC, so one part covers both AC and DC control voltages — a single SKU for mixed-voltage panels. Sensing distance is 15 mm front-only, and the shielded construction lets you flush-mount it in metal without derating. The switching frequency splits by supply: 25 Hz on AC, 500 Hz on DC — if you're counting fast-moving targets on a DC line, that 500 Hz keeps up; on AC, plan for slower objects. The nickel-plated brass body and PPS sensing face, combined with the IP67 / NEMA 3/4X/6P/12/13 enclosure, make it a reliable fit for washdown zones, outdoor racks, and corrosive environments. Rated operating temperature is -13 to 158 °F.
The closest functional sibling is the XS630B1MAL5: same 30 mm shielded barrel, same 15 mm sensing distance, same 24–240 VAC/VDC supply, same load current range. The two critical differences are output configuration and connection. The XS630B1MBU20 has a normally closed (NC) output and a 1/2"-20 UNF male connector; the XS630B1MAL5 has a normally open (NO) output and a 5 m PVR pre-wired cable. If your BOM calls for NC and a connector, the MBU20 is the correct part. If you're replacing a MAL5 in a panel, verify the output logic and whether you have the mating connector — the physical fit is identical, but the electrical behavior is opposite.
If you're sourcing for a multi-year project, there is no immediate obsolescence pressure. The OsiSense XS series is a broad, long-running product family, so future availability of the same form-fit-function part is high. For a guaranteed match, however, always source the exact order code against your current production revision.