Generic LJ30A3-15-Z/AY Inductive Proximity Sensor, PNP NC, 15mm Range, 6-36VDC, IP65, Brass-Nickel Housing

This LJ30A3 model has a PNP (sourcing) output. In the Normally Closed (NC) configuration, the signal wire outputs the supply voltage when no target is detected. When a metal target enters the 15mm range, the output switches to 0V. PNP outputs are typically wired to PLCs with sinking digital inputs. An NPN version would have the opposite switching logic and is used with sourcing PLC inputs.

Yes, inductive proximity sensors can detect all conductive metals, but the effective sensing distance is reduced for non-ferrous metals compared to ferrous metals like steel. For the LJ30A3-15-Z/AY, the 15mm nominal range is specified for mild steel. For aluminum or copper, you should derate the sensing distance, typically to 40-60% of the rated value, and test in your specific application.

Connect the brown wire to your DC positive supply (6-36VDC), the blue wire to DC negative (0V/GND). The black wire is the PNP output signal. In its NC state, with no target present, the black wire will be at the supply voltage. When a metal target is detected within range, the black wire switches to 0V. Always connect the black wire to your PLC's digital input, ensuring the input is configured for a sinking (NPN) connection to read the signal correctly.

Non-shielded means the sensor's electromagnetic field is not restricted laterally, allowing it to detect metal from the sides as well as the front. Therefore, during installation, you must maintain a clearance zone around the sensor body to prevent false triggering from adjacent metal structures or the mounting bracket itself. Refer to the datasheet for the required side and rear clearance distances, which are typically 1-2 times the sensor's diameter.