STA4A-2131A024MF-EX (Order no. 115585)
STA ATEX safety switch, M20 x 1.5 cable entry, contacts for door position
- ATEX version
- 3 x cable entry M20 x 1.5
- Contacts for the door position
- Auxiliary release
- Open-circuit current principle

Description
Version ATEX
Suitable for use in zones 2 and 22 (gases and dusts).
Areas of application:
II 3 G
II 3 D
Use the cable gland supplied.
Approach direction
Horizontal and vertical
Can be adjusted in 90° steps
Increased overtravel for horizontal approach direction
If increased play is required when the door is closed, an actuator with overtravel is available. With this actuator the door can move slightly in the actuating direction when closed. This is important, for example, if safety doors have a rubber end stop. Using an actuator with overtravel, the continuous pressure from the compressed rubber can be reduced. In this way the load is reduced on the switch head and the door mechanism.
Guard locking principle
Open-circuit current (power on to lock): On a guard with guard locking based on the open-circuit current principle, the guard is locked until the power supply to the guard locking solenoid is interrupted. Unlocking is by spring force. The term electrical guard locking is also used.
Switching element
2131 | Slow-action switching contact |
Contacts for guard locking: 2 positively driven contacts | |
Contacts for door monitoring: 1 NC contact |
Auxiliary release
The auxiliary release on the front makes it possible to access the machine if there is a malfunction, e.g. a power failure. Unlocking is performed using a tool or a key. The auxiliary release must be protected against misuse (sealing, lacquer).
Scope of delivery ATEX
ATEX cable gland M20 x 1.5 included.
Accessories required
Actuator is not included.
Functional drawings

Dimensional drawings

| 1 | Auxiliary release |
| 2 | Cover screw (4x M = 1.5 Nm) |
| 3 | Locking screw |
| 4 | Ground the switch via the terminal on the protective plate to prevent electrostatic charging (conductor cross-section 4 mm²) |
| 5 | ATEX cable gland enclosed (cable diameter 7...13 mm) |
| 6 | Two screw plugs included (M = 2 Nm) |
Connection examples

![]() | Door monitoring |
![]() | Solenoid monitoring |
Technical data
Approvals


Electrical connection values
| Fuse | max. 4 A gG |
| Power consumption | 8 W |
| Connection cross section | 0.34 ... 1.5 mm² |
| Rated insulation voltage Ui | 50 V |
| Rated impulse voltage Uimp | 2.5 kV |
| Utilization category | |
| AC-15 | 4 A 50 V |
| DC-13 | 4 A 24 V |
| Solenoid operating voltage | |
| AC/DC | 24 V -15% ... +10% |
| Solenoid duty cycle | 100 % |
| Switching voltage | |
| min. at 10 mA | 12 V |
| Switching current | |
| min. at 24 V | 1 mA |
| thermal rated current Ith | 4 A |
Mechanical values and environment
| Anfahrgeschwindigkeit | max. 20 m/min |
| Approach direction | A |
| Connection type | |
| 3 x | Cable entry M20 x 1.5 |
| Number of door position NC contacts | 1 |
| Number of guard lock monitoring NO contacts | 1 |
| Number of guard lock monitoring positively driven contacts | 2 |
| Extraction force | 30 N |
| Actuation frequency | max. 1200 1/h |
| Actuating force | 35 N |
| Installation orientation | any |
| Insertion depth | 24.5 mm |
| Clamping range for cable | 6.5 ... 12 mm |
| Storage temperature | -25 ... 75 °C |
| Mechanical life | 1 x 10⁶ |
| Retention force | 20 N |
| Switching principle | Slow-action switching contact |
| Degree of protection | IP67 |
| Ambient temperature | -20 ... 75 °C |
| Material | |
| Contact | Silver alloy, gold flashed |
| Housing | Die-cast alloy |
| Locking force Fmax | 3000 N |
| Locking force FZh | 2300 N |
| Guard locking principle | Open-circuit current principle |
Characteristic values according to EN ISO 13849-1 and EN IEC 62061
| B10D | Mission time | |
|---|---|---|
| Guard lock monitoring | 1.15x107 | 20 y |
| Important! Values valid at DC-13 100 mA/24V | ||
Miscellaneous
| Explosion protection in accordance with ATEX Directive 2024/34/EU | |
| incl. cable gland | II3G Ex nR IIB T4 Gc X /II3D Ex tc IIIC T110°C Dc X |
In combination with actuator ACTUATOR-S-G-SN-C2115
| Overtravel | 5 mm |
Accessories
Downloads
Complete package
Download all important documents with a single click.
Content:
- The operating instructions and any additions to the operating instructions or brief instructions
- Any data sheets to supplement the operating instructions
- The declaration of conformity
Single Documents
Other Documents
Ordering data
| Ordernumber | 115585 |
| Item designation | STA4A-2131A024MF-EX |
| Gross weight | 0,94kg |
| Customs tariff number | 85365019000 |
| ECLASS | 27-27-26-03 Safety switch with guard control |
+ 1 NO contact














