CNC machine tools
Safety contacts plus auxiliary feedback to the CNC for door-state display.
Safety Interlock · Electromagnetic, 2 / 4 / 6 contacts
QSD-K6 & SDP Electromagnetic Safety Interlock Series
Electromagnetic interlocks with 2, 4 or 6 contacts and a 1300 N locked-state tensile strength — for machine tools that need more contacts than a basic interl
Model QSD-K6 / QSD / SDP · Brand LE Raun · Category: Safety Door Locks & Interlocks
Contacts2 / 4 / 6
Tensile strength1300 N
Rated thermal current10 A
ProtectionIP67
Overview
Three contact configurations share one housing family: QSD-K6 with six contacts, QSD with two and SDP with four. All three lock with 1300 N of tensile strength, carry a 10 A thermal rating and switch AC-15 / DC-13 loads at 3 A.The extra contacts are what machine builders usually need: two for the safety circuit, plus auxiliary contacts to tell the PLC the door state, drive a lamp or interlock a second axis — without adding a separate switch and a second actuator on the door.
Application scenarios
Injection moulding machines
Multi-contact interlock on the mould-area guard.
Packaging machines
Door monitoring where the PLC also needs a door-closed signal.
Machining centres
Interlocks the tool-change and load openings with separate auxiliary contacts.
Special-purpose machines
Where a single switch has to report state to both the safety relay and the PLC.
Industries
- Machine tools
- Injection moulding
- Packaging
- General machinery
Technical specifications
| Models | QSD-K6-□□□□□ (6 contacts) · QSD-□□□□□ (2 contacts) · SDP-□□□□□ (4 contacts) |
|---|---|
| Housing material | Flame-retardant Pa66 |
| Contact material | Copper contacts |
| Tensile strength in locked state | 1300 N |
| Rated insulation voltage | 300 V |
| Rated impulse withstand voltage | 4.0 kV |
| Rated thermal current | 10 A |
| Utilization category | AC-15 / DC-13 |
| Rated operational current | 3 A |
| Forced release distance | ≥10 mm |
| Permissible operating speed | 0.05–0.5 m/s |
| Protection level | IP67 (per EN 60947-5-1, except for key-actuation aperture) |
| 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. |
| Contact resistance | ≤25 mΩ |
| Mechanical life | 1,000,000 operations |
| Electrical life | 500,000 operations |
| Operating frequency | 0.05–1 Hz (max. 120 operations per minute) |
| Ambient temperature | −25 … +80 °C, no icing |
Dimensions
| Item | Value |
|---|---|
| Actuator entry | 0.1 – 0.3 mm gap, centred to ±1 mm |
| Door-chain radius | R ≥ 300 mm for the chain or hinge used to carry the actuator |
| Cable | 2 m, direct outlet |
The head unscrews and turns so the cable can leave in any of four directions — set that before you drill, because the 4 screws are the only fixing points on the body.
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
Three contact counts
2, 4 or 6 contacts in the same footprint, so the panel layout does not change between machine variants.
1300 N locked-state strength
Holds the guard against the load a heavy door puts on the bolt.
IP67 body
Sealed to EN 60947-5-1 for coolant and chip environments.
Questions
Which contact count do I need?
Two contacts are enough for a simple series safety circuit. Choose 4 or 6 when the PLC also needs door-state feedback, a lamp, or a second interlocked axis.
Is the tensile strength the same for all three?
Yes — 1300 N in the locked state for QSD-K6, QSD and SDP.
What voltage can it switch?
Rated operational voltage is 400 V for the 2- and 4-contact versions and 240 V / 30 V / 250 V for the 6-contact version, at 3 A operational current.
Need a quotation for QSD-K6 &?
Send your application details or the guard opening dimensions and we will specify the right model and configuration for your machine.