A 4-wire DC inductive proximity switch carries two conductors for the DC supply and two separate output conductors — one normally open and one normally closed. You get both switching states from a single sensor without doubling up hardware.
Why choose a complementary-output sensor
Many control schemes need both states at once: the NO contact drives the machine sequence while the NC contact feeds a fault-monitoring or safety-check circuit. Using one 4-wire sensor instead of two 3-wire sensors saves a mounting position, halves the alignment work, and guarantees both signals refer to exactly the same trigger point.
Key features
- Two independent outputs — NO and NC available simultaneously.
- Single trigger point — both outputs switch from the same sensing face, so there is no timing offset.
- Fault detection ready — cross-check the two outputs to spot a failed sensor or broken cable.
- PNP or NPN — specify to suit your input card.
- IP68 brass housing with short-circuit and reverse-polarity protection.
Technical specifications
| Parameter | Value |
|---|---|
| Wiring | 4-wire DC (2 supply + NO output + NC output) |
| Output type | PNP or NPN, complementary NO and NC |
| 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
- Safety and interlock circuits needing a monitored complementary pair.
- Position confirmation where one signal drives the sequence and another logs the state.
- Retrofits onto machines whose control logic expects both NO and NC from one device.
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
Can I use only one of the two outputs?
Yes. Leave the unused output disconnected and insulated. Many customers buy the 4-wire version simply to keep one spare part number on the shelf that suits both NO and NC applications.
Is a 4-wire sensor a safety-rated device?
No. A complementary-output proximity switch helps with plausibility checking, but it is not a certified safety component. For guarding a hazardous zone, use our IR safety light curtain instead.
Need a quote for the 4-Wire DC Proximity Switch (NO + NC)?
Send us your application — target material, sensing distance, supply voltage and housing constraint. We will recommend a part, quote it, and ship from Mumbai.