During technical comparisons, REL-MR-24DC-21-MS appears alongside SMPS Phoenix, Phoenixcontact Rel Ir Bl L 230Ac 4X21 and Phoenixcontact Phoenix Contact Industrial Ethernet Switches so engineers assess signal types, ingress protection, and ambient tolerances accurately.
Phoenix REL-MR- 24DC/21/MS Single Relay
The Phoenix REL-MR- 24DC/21/MS Single Relay (Part No: 2909642 ) offers a 24 V DCnominal input voltage UN, 14.4 V DC ... 66 V DC input voltage range, 250 V AC/DC switching voltage, Plug / solder connection method. Manufactured by Phoenix under the Phoenix Single Relay category, this model belongs to the Phoenix REL Series.
| Brand | Phoenix Contact |
| Product Type | Single Relay |
| Model Number | REL-MR- 24DC/21/MS |
Phoenix REL-MR- 24DC/21/MS Single Relay β Technical Specifications
| Specification | Value |
|---|---|
| Product type | Single relay |
| Mechanical service life | 1x 107 cycles |
| Insulation | - |
| Overvoltage category | III |
| Pollution degree | 3 |
| Service life electrical | - |
| Maximum power dissipation for nominal condition | 0.17 W |
| Test voltage (Winding/contact) | 4 kV AC (50 Hz, 1 min., winding/contact) |
| Test voltage (Changeover contact/changeover contact) | - |
| Rated insulation voltage | - |
| Rated surge voltage | - |
| Nominal input voltage UN | 24 V DC |
| Input voltage range | 14.4 V DC ... 66 V DC |
| Drive and function | monostable |
| Drive (polarity) | non-polarized |
| Typical input current at UN | 7 mA |
| Typical response time | 2.5 ms |
| Coil voltage | - |
| Status display | - |
| Contact switching type | 1 changeover contact |
| Type of switch contact | Single contact |
| Contact material | AgSnO |
| Maximum switching voltage | 250 V AC/DC |
| Minimum switching voltage | 5 V (100 mA) |
| Limiting continuous current | 6 A |
| Maximum inrush current | 10 A (4 s) |
| Min. switching current | 10 mA (12 V) |
| Interrupting rating (ohmic load) max. | 140 W (24 V DC) |
| Connection method | Plug / solder connection |
| Width | 5 mm |
| Height | 28 mm |
| Depth | 16 mm |
| Degree of protection | RT II |
| Degree of protection (Installation location) | - |
| Ambient temperature (operation) | -40 Β°C ... 85 Β°C |
| Ambient temperature (storage/transport) | -40 Β°C ... 85 Β°C |
| Standards/regulations | IEC 60664 |
| Mounting type | Plug-in mounting |
| Mounting position | any |
| Mains frequency | - |
| Typical release time range | - |
| Coil resistance | 3390 Ξ© Β±10 % (at 20 Β°C) |
| Switching capacity | 2 A (24 V (DC13)) |
| Motor load according to UL 508 | 1/4 HP, 240 - 277 V AC (N/O contact) |
| Input power dissipation for UN | - |
| 3-phase motor load | - |
| Product family | - |
| Relay type | - |
| Test voltage () | - |
| Degree of protection (Relay) | - |
| Inrush current, minimum | - |
| Non-operate voltage | - |
| Safe operate voltage | - |
| Test voltage (N/O contact / N/O contact) | - |
The Phoenix Contact REL-MR-24DC/21/MS (Part No: 2909642) is engineered for accurate, consistent, and energy-efficient control performance in industrial panels. It operates within a broad input voltage range of 14.4 V DC to 66 V DC, consuming only 7 mA at its nominal 24 V DC. This makes the Phoenix 7 mA Input Current Single Relay ideal for applications that demand stable low-power operation without overheating or current spikes. Its monostable drive and non-polarized input design simplify wiring while ensuring quick response times of 2.5 ms, improving control precision in automated systems.
Built with silver-tin oxide (AgSnO) contacts, the relay supports a single changeover configuration rated up to 250 V AC/DC, handling a continuous current of 6 A and inrush currents up to 10 A for 4 seconds. It delivers high mechanical durability with a service life of 10 million cycles and a compact 5 mm width, allowing engineers to save panel space without sacrificing reliability. Conforming to IEC 60664 standards and protected to RT II level, it ensures insulation safety and operational stability across temperatures from β40 Β°C to +85 Β°C. These features make the REL-MR-24DC/21/MS 2909642 one of the most dependable relays for signal and control circuits in industrial automation.
Engineers and maintenance professionals use the Phoenix Contact Single Relay in PLC panels, process controllers, and safety circuits that require quick and stable contact switching. Its low input current helps in conserving power, especially in systems driven by limited DC supplies. The compact design with plug-in mounting ensures easy installation and replacement during machine maintenance. In factory automation, energy plants, or machine-tool assemblies, this relay provides efficient control feedback and signal isolation between low-voltage control and high-power loads. Students in industrial training labs also rely on the Phoenix REL-MR-24DC/21/MS 2909642 to understand switching response, coil resistance, and insulation design in real-time applications.
The REL-MR-24DC-21-MS-2909642 stands out for precision, compactness, and reliability in demanding automation systems. Many engineers refer to it as the REL-MR- 24DC/21 β Single Relay due to its optimized coil design and stable switching behavior. The Phoenix REL-MR-24DC/21 and Phoenix Contact REL-MR-24DC/21 models ensure dependable operation in harsh industrial environments while maintaining minimal power loss. Its consistent 7 mA input current and robust contact performance make it a preferred choice for advanced control panels and OEM applications. Choose the 21 MS series for precise, space-saving relay performance built to meet Phoenix Contactβs trusted industrial standards.
