The Pepperl+Fuchs (P+F) NCN4 and NCB5 are inductive proximity sensors with a NAMUR standard output interface. Unlike mechanical limit switches they have no mechanical contacts, so their service life is not limited by the number of actuations. The NAMUR output (8.2 V low voltage, with current switching according to whether metal is present) is the standard for intrinsically safe circuit design in petrochemical and chemical plants and can be used safely in explosive gas atmospheres.
※ A NAMUR circuit must be combined with a safety barrier (Zener barrier or galvanic barrier) to form an intrinsically safe loop.
Model specifications
| Model | Housing | Sensing range | Output type | Supply | Cable |
|---|---|---|---|---|---|
| NCN4-12GM35-N0-V1 | M12×1 | 4 mm (non-flush) | NAMUR, normally closed (NC) | 8.2 V (Ri ≈ 1 kΩ) | M12×1 4-pin connector (V1, cable not included) |
| NCB5-18GM40-N0 | M18×1 | 5 mm (flush) | NAMUR, normally closed (NC) | 8.2 V (Ri ≈ 1 kΩ) | 2 m PVC cable (0.75 mm²) |
NAMUR output: how current switching works
A NAMUR sensor does not output a voltage signal; it indicates its state by current level: with no metal target the current is ≥3 mA (conducting), and when a metal target approaches the current is ≤1 mA (blocked). The safety barrier reads this current difference and converts it into a control signal. The advantage of this design is that on a cable break the current drops to 0, so the control system can tell “no target” from “broken cable” — it has built-in wire-break fault detection.
Flush / non-flush mounting
The NCB5-18GM40-N0 is a flush (embeddable) type — the sensor face can be embedded in a metal mounting bracket without affecting the sensing range, suiting compact mechanical designs. The NCN4-12GM35-N0-V1 is a non-flush type — a metal-free zone must be left around the sensor face (dimensions per the manufacturer’s mounting drawing) in exchange for a longer sensing range.
Trademarks: Pepperl+Fuchs and the model names on this page are trademarks or model names of their owner, used here only to identify the products. JIAHON is not the authorized distributor of Pepperl+Fuchs in Taiwan.
Request a quote
Send the full model numbers and quantities, or ask us to confirm specifications. Request a quote →