LE40XZSN20DPO-D, LANBAO, rectangular inductive sensor, 40x40x140mm, Sn 20 mm, PNP, NO, screw terminals

LE40XZSN20DPO-D – Inductive proximity sensor in a rectangular housing

LANBAO LE40XZSN20DPO-D inductive proximity sensor in a rectangular housing, housing 40x40x140mm, for reliable detection in machines and production lines. It detects metal objects without contact using an electromagnetic field; the rectangular housing is screwed onto a flat surface, so it needs no threaded hole or nuts.

Key features

• Sensing distance 20 mm – rated value for a standard steel target.
• PNP output, NO contact – normally open – connects to a PLC digital input or a relay coil.
• Supply 10–30 V DC.
• Non-flush mounting.
• Connection: screw terminals.
• Degree of protection IP67 – protection against dust and temporary immersion.

How an inductive sensor works

The coil in the sensing face generates a high-frequency magnetic field. When a metal object enters the field, it induces eddy currentsin its surface, which draw energy from the field and dampen it. As soon as the damping exceeds the set threshold, the evaluation circuit switches the output. All this happens without any contact, so the sensor has no mechanically wearing parts.

High-frequency oscillation principle: coil field, eddy currents in the metal target and their damping effect.

Correction factor – why the range on aluminium differs from steel

The rated sensing distance applies to a standard steel target. For other metals it is reduced by a correction factor. Calculate the actual distance as the rated Sn multiplied by the material factor.

Standard target and tolerance

According to the manufacturer's catalogue, the standard target is a square plate of St37 steel, 1 mm thick. The side length equals the larger of: the diameter of the sensing face, or three times the sensing distance. A smaller target means a shorter range. The sensing distance tolerance is ±10 %, so never set the working point exactly at the Sn limit.

Technical specifications LE40XZSN20DPO-D

Wiring of LE40XZSN20DPO-D by wire colours

The colour coding complies with IEC 60947-5-2. Always compare the actual pin and wire assignment with the diagram in the sensor datasheet (Downloads tab).

Three-wire cable wiring according to IEC 60947-5-2.

Mounting and free space

The sensor has a non-flush sensing face and must protrude from the metal. Metal in the axis of the face shortens the range or causes permanent switching, so the free space shown in the dimension drawing must be maintained.

Non-flush mounting: free space must remain around the face.

Mutual interference of sensors

Two sensors mounted close to each other may interfere with each other. If you need to sense at two adjacent points, keep the lateral spacing given in the sensor's dimension drawing, or offset the sensors so that their faces do not point into the same space.

Set the working distance to 70 to 80 % of the rated Sn, i.e. safely below 20 mm for this model. The tolerance is ±10 % and the distance also changes with temperature and supply voltage.

Typical applications

• mounting on a flat frame or profile without drilling a threaded hole
• position detection in narrow and confined machine spaces
• monitoring stops and end positions of handling devices
• checking the presence of a metal part in a tray or magazine
• applications where sensing from the side rather than along the axis is needed

How to choose and what to watch out for

• Non-flush mounting: the face must remain free. Surrounding metal in the axis of the face shortens the range or causes permanent switching – keep the free space shown in the dimension drawing.
• PNP output (switches plus) matches the standard PLC digital inputs used in Europe. For NPN-type inputs, choose the corresponding variant with the same sensing distance.
• NO contact (normally open): the output is activated when an object is detected. If you need the opposite logic, an NC variant is available.
• Degree of protection IP67: protection against dust and temporary immersion. Not designed for permanent immersion or high-pressure washing – this requires IP69K.
• Sensing distance 20 mm is the rated value for a standard steel target. For stainless steel, brass, aluminium or copper it is reduced by a reduction factor – if you detect non-ferrous metals, allow a margin or choose a model with correction factor 1.

PNP or NPN – and what happens if you mix them up

PNP switches the positive pole, so it sends plus to the PLC input. It is the European standard and matches standard digital inputs. NPN switches minus and is used mainly in Asian equipment. If mixed up, the sensor either does not switch at all or reports a permanently active state — it usually will not be damaged, but it will not work.

This model has a PNPoutput. If you need NPN, a variant with the same sensing distance is available — contact us and we will recommend the code.

NO or NC – and why it is not just a matter of convenience

NO (normally open) is an output that is active on detection. NC (normally closed) is active at rest and opens on detection. The difference is a safety one: with NC, a broken wire causes the same reaction as a detection, so the fault shows up immediately. With NO, a broken cable remains unnoticed until someone tries to switch.

This model has the contact NO – normally open.

Similar models in the same series

• LE40XZSN20DLO-D
• LE40XZSN20DNC-D
• LE40XZSN20DNO-D
• LE40XZSN20DNR-D
• LE40XZSN20DPC-D

Frequently asked questions

Does LE40XZSN20DPO-D have a PNP or NPN output?

LE40XZSN20DPO-D has a PNP output with an NO contact – normally open. It therefore matches the standard PLC digital inputs used in Europe.

What is the sensing distance of LE40XZSN20DPO-D?

The sensing distance (Sn) is 20 mm. This is the rated value for a standard steel target; the range is shorter for non-ferrous metals.

How is LE40XZSN20DPO-D connected?

LE40XZSN20DPO-D is supplied with the connection: screw terminals. The cable is part of the sensor; the other end is free for connection to a terminal block.

How is LE40XZSN20DPO-D wired by wire colours?

Brown wire to supply plus, blue to minus, and black is the signal output going to the PLC input or relay coil. The coding complies with IEC 60947-5-2.

Why choose a rectangular housing instead of a cylindrical M12/M18?

A rectangular housing is screwed onto a flat surface with two screws and does not require a threaded hole with nuts. It is suitable where there is no room for a cylindrical body or where sensing from the side is needed.

A detailed datasheet with a dimension drawing and wiring diagram can be found in the tab Downloads.