Procurement teams shortlist PLC-RSC-24DC-21-21-EX with SMPS Phoenix, PLC Rsc 230Uc 21 and Phoenixcontact Phoenix Contact Industrial Ethernet Switches, aligning budget approvals, warranty terms, and multisite availability for smoother rollout across plants.
Phoenix PLC-RSC- 24DC/21-21/EX Relay Module
The Phoenix PLC-RSC- 24DC/21-21/EX Relay Module (Part No: 2909509 ) offers a 24 V DC nominal input voltage UN, 20.2 V DC ... 33.6 V DC (20 Β°C) input voltage range, polarized Drive, 8 ms typical response time. Manufactured by Phoenix under the Phoenix Relay Module category, this model belongs to the Phoenix PLC Series.

| Brand | Phoenix Contact |
| Product Type | Relay Module |
| Model Number | PLC-RSC- 24DC/21-21/EX |
Phoenix PLC-RSC- 24DC/21-21/EX Relay Module β Technical Specifications
| Specification | Value |
|---|---|
| Product type | Relay Module |
| Product family | PLC-INTERFACE |
| Application | Class I, Division 2 |
| Mechanical service life | 3x 107 cycles |
| Insulation | Safe isolation, reinforced insulation |
| Overvoltage category | III |
| Pollution degree | 3 |
| Maximum power dissipation for nominal condition | 0.43 W |
| Test voltage (Winding/contact) | 4 kV AC (50 Hz, 1 min., winding/contact) |
| Test voltage (Changeover contact/changeover contact) | 2.5 kV AC (50 Hz, 1 min., changeover contact/changeover contact) |
| Rated surge voltage | 6 kV |
| Nominal input voltage UN | 24 V DC |
| Input voltage range | 20.2 V DC ... 33.6 V DC (20 Β°C) |
| Drive and function | monostable |
| Drive (polarity) | polarized |
| Typical input current at UN | 18 mA |
| Typical response time | 8 ms |
| Typical release time | 10 ms |
| Protective circuit | Reverse polarity protection; Polarity protection diode |
| Operating voltage display | Yellow LED |
| Contact switching type | 2 changeover contacts |
| Type of switch contact | Single contact |
| Contact material | AgNi |
| Maximum switching voltage | 250 V AC/DC (The separating plate PLC-ATP should be installed for voltages larger than 250 V (L1, L2, L3) between identical terminal blocks in adjacent modules. Potential bridging is then carried out with FBST 8-PLC... or ...FBST 500...) |
| Limiting continuous current | 6 A |
| Maximum inrush current | 15 A (300 ms) |
| Min. switching current | 10 mA (5 V) |
| Interrupting rating (ohmic load) max. | 140 W (at 24 V DC) |
| Switching capacity | 2 A (at 24 V, DC13) |
| Connection method | Screw connection |
| Stripping length | 8 mm |
| Conductor cross section rigid | 0.14 mmΒ² ... 2.5 mmΒ² |
| Conductor cross section flexible | 0.14 mmΒ² ... 2.5 mmΒ² |
| Conductor cross section AWG | 26 ... 14 |
| Tightening torque | 0.6 Nm ... 0.8 Nm |
| Width | 14 mm |
| Height | 80 mm |
| depth | 94 mm |
| Color | gray (RAL 7042) |
| Flammability rating according to UL 94 | V0 (Housing) |
| Degree of protection (Relay) | RT III (Relay) |
| Degree of protection (Relay base) | IP20 (Relay base) |
| Ambient temperature (operation) | -40 Β°C ... 70 Β°C (UL) |
| Ambient temperature (storage/transport) | -40 Β°C ... 85 Β°C |
| Temperature | D |
| Humidity | A |
| Vibration | B/C |
| EMC | B |
| Enclosure | Required protection according to the Rules shall be provided upon installation on board |
| Low Voltage Directive | Conformance with Low Voltage Directive |
| Electromagnetic compatibility | Conformance with EMC directive |
| Standards/regulations | IEC 60947-5-1 |
| Mounting Type | DIN rail mounting |
| Mounting position | any |
| Contact Connection type | - |
| Output fuse | - |
| Degree of protection (Installation location) | - |
The Phoenix Contact Relay Module PLC-RSC-24DC/21-21/EX (Part No: 2909509) delivers reliable switching and safe electrical isolation across demanding automation environments. This Phoenix Contact PLC-Interface Relay Base operates at a nominal input voltage of 24 V DC, drawing approximately 18 mA for efficient control circuit performance. Engineered for durability, it offers a mechanical service life of 3Γ10β· cycles with AgNi contact material ensuring long-term switching stability. Its Class I, Division 2 compliance and IEC 60947-5-1 certification make it suitable for hazardous and industrial environments. Built with DIN rail mounting support and a screw connection interface, the design simplifies installation and ensures firm electrical contact. The module includes reverse polarity protection, a yellow LED indicator for active operation, and reinforced insulation to handle surge voltages up to 6 kV. With a maximum switching voltage of 250 V AC/DC and inrush current capacity of 15 A (300 ms), the Phoenix Contact Relay Module PLC-RSC-24DC/21-21/EX (2909509) ensures consistent performance under varied industrial load conditions.
The Phoenix Contact Relay Module PLC-RSC-24DC/21-21/EX is widely used in industrial control panels, process automation systems, and manufacturing lines where signal isolation, control precision, and durability are essential. Its PLC-INTERFACE design allows seamless integration with automation controllers, PLCs, and other control devices, reducing wiring complexity and improving service life. Engineers prefer this model for its stable electrical performance, low maintenance requirements, and long operational endurance. In Class I, Division 2 zones or continuous-duty control systems, it minimizes downtime and ensures stable relay switching even under fluctuating loads and vibration conditions.







