The STP is a solenoid-operated safety switch with guard locking, combining door position monitoring with locking status feedback in a single device. It operates on the open-circuit current principle, applying voltage to the guard locking solenoid to lock and releasing by spring force, with a slow-action switching contact arrangement of 2 NC + 1 NO + 1 NC covering door and guard lock monitoring. Locking forces of up to 2500 N and a reinforced thermoplastic housing rated IP67 suit it to guarding applications on machine access doors where reliable interlocking is required. An auxiliary release and locking screw are provided for manual operation and installation.
Key specifications
| STP4 | Open-circuit current principle, guard locking by applying voltage to the guard locking solenoid. Release by spring force. |
| 2131 | Slow-action switching contact 2 NC + 1 NO + 1 NC (door monitoring contact) |
This is used for releasing the guard locking with the aid of a tool. To protect against tampering, the auxiliary release is sealed with sealing lacquer.
Electromechanical safety switches in use
| 1 | Auxiliary release |
| 2 | Locking screw |
| Door monitoring | |
| Solenoid monitoring |
| Power consumption | 8 W |
| Connection cross section | 0.34 - 1.5 mm² |
| Rated insulation voltage Ui | 250 V |
| Rated impulse withstand voltage Uimp | 2.5 kV |
| Utilization category | |
| DC-13 | 4 A 24 V |
| AC-15 | 4 A 230 V |
| Short circuit protection according to IEC 60269-1 | 4A gG |
| 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 |
| Approach speed | max. 20 m/min |
| Approach direction | A |
| Connection type | 3 x 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 |
| Mechanical life | 1 x 10⁶ |
| Retention force | 20 N |
| Switching principle | Slow-action switching contact |
| Degree of protection | IP67 |
| Ambient temperature | -20 ... +55 °C |
| Material | |
| Contact | Silver alloy, gold flashed |
| Housing | Reinforced thermoplastic |
| Locking force Fmax | 2500 N |
| Locking force FZh | 2000 N |
| Guard locking principle | Open-circuit current principle |
Declarations of conformity
EU declaration of conformity
| EDC20001551 |
Operating Instructions Safety Switch STP…
Safety information
Approvals and certificates
AUCOTEAM
Approval
CCC
c UL us
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| Item designation | STP4A-2131A024M |
| Gross weight | 0,525kg |
| Customs tariff number | 85365019000 |
| ECLASS | 27-27-26-03 Safety switch with guard control |