A 2-wire DC inductive proximity switch wires directly in series with the load, so you run only two conductors to the sensor instead of three. It is the simplest way to add non-contact metal detection to an existing DC circuit without re-pulling cable.
How a 2-wire DC sensor is wired
The load — a relay coil, PLC input or contactor — sits in series with the switch. Supply voltage is shared between the two: the sensor drops roughly 6 V across itself and the remainder appears across the load. Because of that drop, check that your load still operates at its minimum rated voltage before choosing a 2-wire part.
Unlike a NAMUR sensor, a 2-wire DC switch drives the load directly. No external amplifier or isolating switching unit is needed.
Key features
- Two-conductor wiring — load connects in series, halving the cable cores versus a 3-wire sensor.
- Drives loads directly — handles higher voltage and current than NAMUR types without an amplifier.
- IP68 sealed — chrome-plated brass barrel resists coolant, wash-down and swarf.
- Fault tolerant — built-in short-circuit and reverse-polarity protection survive wiring mistakes.
- Flush or non-flush — choose shielded for mounting level with metal, unshielded for longer range.
- LED status — confirms switching at a glance during commissioning.
Technical specifications
| Parameter | Value |
|---|---|
| Wiring | 2-wire DC, load in series |
| Voltage drop across sensor | Approximately 6 V |
| Rated switching distance | 1 mm to 50 mm, depending on barrel size |
| Hysteresis | 5–10% of the rated sensing distance |
| Repeatability | 5–10% of the rated sensing distance |
| Operating voltage | 10–30 V DC |
| Switching frequency | Up to 200 Hz |
| Housing material | Chrome-plated brass (stainless steel on request) |
| Protection class | IP68 — dust-tight and submersion-proof |
| Mounting | Flush (shielded) or non-flush (unshielded) |
| Protection circuits | Short-circuit and reverse-polarity protected |
| Status indication | LED on the sensor body |
| Standard cable | 2 m, 3-core PVC (custom lengths on request) |
| Available sizes | M8, M12, M18, M30, M50, M80 and rectangular |
Typical applications
- Conveyor systems — part presence and position confirmation.
- Machine controls — end-of-travel and home-position detection.
- Process control — liquid level via float, and part-presence sensing.
- Harsh environments — coolant, wash-down and dusty areas where IP68 matters.
How to order
Tell us the sensing gap, the target material, your supply voltage and the output type your controller needs. If you are replacing an existing sensor, a photograph of the body markings is usually enough for us to identify an equivalent. We will confirm the specification and quote — normally the same day.
Related products
Frequently asked questions
What is the difference between a 2-wire and a 3-wire DC proximity sensor?
A 2-wire sensor puts the load in series with the switch and needs only two conductors, but it drops about 6 V and passes a small residual leakage current when off. A 3-wire sensor has separate supply and output conductors, so there is no voltage drop across the load and no meaningful leakage — which matters when driving sensitive PLC inputs.
Will a 2-wire DC sensor work with a PLC input card?
Usually yes, but check two figures: the residual (leakage) current when the sensor is off must be below the PLC input's OFF threshold, and the voltage remaining after the sensor's ~6 V drop must exceed the input's ON threshold. Tell us your PLC model and we will confirm before you order.
Can I use a 2-wire DC sensor at 24 V DC?
Yes. The operating range is 10–30 V DC, so a standard 24 V DC panel supply is well within specification.
Need a quote for the 2-Wire DC Proximity Switch?
Send us your application — target material, sensing distance, supply voltage and housing constraint. We will recommend a part, quote it, and ship from Mumbai.