LJ4A3-1-Z/BX Inductive Proximity Sensor NPN NO, 10–30VDC, 1mm Detection, IP65, Brass-Nickel Housing

The brown wire connects to the positive DC supply (10–30VDC), the blue wire to the negative/common. The black wire is the NPN output; it switches to ground (sinks current) when a metal target is detected, providing a low signal to a PLC's digital input. Ensure the load (e.g., PLC input) is connected between the black wire and the positive supply.

Yes, inductive sensors detect all conductive metals, but the effective sensing distance is reduced for non-ferrous metals like aluminum or copper compared to steel. For the LJ4A3-1-Z/BX, the 1mm nominal distance is specified for mild steel (Fe360). For non-ferrous metals, expect a reduction factor, typically 0.3 to 0.5 times the stated range.

A shielded (flush-mountable) sensor allows its sensing face to be mounted flush with or embedded within a metal bracket without significant performance degradation. This design prevents the sensing field from extending radially, enabling compact, side-by-side mounting in multi-sensor arrays without mutual interference.

Yes, the sensor incorporates reverse polarity protection. If the brown (positive) and blue (negative) wires are accidentally swapped, the internal protection circuit prevents damage to the electronic components, allowing for safe correction of the wiring without requiring sensor replacement.