Washdown and hygienic areas
Sealed to IP67/IP68 on request, with no mechanical cavity to trap residue — food, pharma and beverage equipment.
Safety Interlock · Non-contact RFID
QSD-M3 Non-Contact RFID Safety Switch
A coded, non-contact interlock with no mechanical actuator to align: 0–10 mm horizontal and 0–8 mm vertical operating distance, dual-channel NPN/PNP output,
Model QSD-M3 Series · Brand LE Raun · Category: Safety Door Locks & Interlocks
Operating distance10 mm / 8 mm
OutputDual-channel NPN / PNP
Response time60 ms
ProtectionIP65 / IP67 / IP68
Overview
The QSD-M3 replaces the mechanical actuator with an RFID-coded pair: a read head on the frame and a coded target on the door. There is nothing to bend, and the switch tolerates 10 mm of horizontal and 8 mm of vertical misalignment before it changes state.Eight codes cover the range: NPN or PNP output, standard 4-core cable or a 6-core cascade version that lets several switches share one cable run, and W versions with an actuator carrying a unique code — so a spare target from the stores will not satisfy the switch.
Application scenarios
High-vibration doors
No actuator to wear or misalign on machine tools with heavy vibration.
Multi-door machines
Cascade versions chain several switches on one cable run.
Guard doors that sag
The 10 mm operating distance keeps working as hinges settle.
Cells needing tamper resistance
Unique-coded actuators prevent bypass with a spare part.
Washdown guard on a food line
The potted IP69K version survives high-pressure cleaning that destroys a mechanical actuator.
Guard with poor alignment
A 10 mm switching distance tolerates door sag that would jam a keyed interlock.
Defeat-resistant machine cover
A uniquely coded pair cannot be bypassed with a spare actuator bought off the shelf.
Industries
- Food processing
- Pharmaceutical
- Machine tools
- Packaging
Technical specifications
| Model | QSD-M3 series (8 codes) |
|---|---|
| Cable outlet | 4-core / 6-core direct cable outlet, 2 m |
| Output type | Dual-channel NPN or PNP output |
| Horizontal operating distance | Conduction 0–10 mm |
| Vertical operating distance | Conduction 0–8 mm |
| Operating voltage | 24 V DC ±15% |
| Operating current | 30 mA |
| Output current | 100 mA |
| Response time | 60 ms |
| Operating frequency | 1 Hz |
| Operating temperature | −10 °C to +55 °C |
| Relative humidity | 5%–95% |
| Protection level | IP65 / IP67 / IP68 (custom) |
| Product application | Suitable for CNC machine tools, injection-moulding equipment, semiconductor manufacturing equipment, etc. It ensures that the machine does not perform hazardous movements when the safety guard door is opened. |
| Housing material | Flame-retardant thermoplastic (metal body on the high-performance series) |
| Contact material | Silver alloy |
| Contact resistance | ≤25 mΩ |
| Rated insulation voltage | 500 V |
| Rated impulse withstand | 4 kV |
| Utilisation category | AC-15 / DC-13 |
| Mechanical life | 1,000,000 operations |
| Electrical life | 500,000 operations |
| Ambient temperature | −25 … +80 °C, no icing |
Dimensions
| Item | Value |
|---|---|
| Actuator | 36 × 22 × 11.5 mm, matched pair |
| Switching distance | ON ≤10 mm horizontal / ≤8 mm vertical; OFF ≥15 mm |
| Housing | Flame-retardant plastic, potted, IP68 / IP69K option |
| Cable | 0.3 / 2 / 5 / 10 m ordered by suffix |
| Weight | approx. 60 g per unit |
The two rectangles must face each other within the operating area shown in the catalogue; offset beyond 10 mm in Y and the output is undefined.
Wiring & output
| Terminal | Contact |
|---|---|
| 21 – 22 | NC, positive opening (second circuit) |
| 33 – 34 | NO |
| 41 – 42 | NO (where fitted) |
How to specify
- 01
Decide whether the guard must be locked
Monitoring only (mechanical interlock) is enough where the machine stops within the time the door needs to open. Locking is required where a spindle, press or robot arm keeps moving after the stop command.
- 02
Choose the coding
Mechanical actuation is the simplest and cheapest. RFID and magnetic coding resist defeat with a spare actuator, tolerate misalignment and are the usual choice on washdown or vibrating guards.
- 03
Pick the contact configuration
Count the circuits: two NC for a dual-channel safety input, one NO for the door-closed signal to the PLC, plus one more NO if the lock state has to be reported separately.
- 04
Check the holding force against the door
Fzh is the force the lock withstands before the guard can be pulled open. Large sliding guards and guards with a long lever need the 2,000 N class rather than the 1,300 N class.
- 05
Allow for the actuator radius
The actuator swings on the door hinge; the catalogue gives the minimum door radius for each model. Below that radius the actuator will bind and the switch will wear out.
Why this series
Nothing to align
10 mm / 8 mm operating distances absorb door sag and frame flex.
Coded actuation
Unique-coding versions defeat the classic bypass with a spare actuator.
Cascade wiring
6-core cascade models cut the cable runs on multi-door machines.
Questions
What is the difference between the N/P and NW/PW versions?
N and P are the standard NPN and PNP outputs. The W versions ship with an actuator carrying a unique code, so only the matching target will close the safety output.
Can I wire several switches in series?
Yes — the CN and CP (cascade) models have a 6-core outlet designed for chaining switches on one cable run.
How much misalignment is acceptable?
Conduction is guaranteed from 0–10 mm horizontally and 0–8 mm vertically; outside that range the output opens.
Unique coding or no coding?
Order the W (unique) code where a spare actuator could defeat the guard — every pair is matched at the factory. The N (no-code) version is cheaper and is used where all actuators are interchangeable by design.
Related products
Need a quotation for QSD-M3 Non-Contact?
Send your application details or the guard opening dimensions and we will specify the right model and configuration for your machine.