Phoenix REL-MR- 24DC/21-21/MS Single Relay
The Phoenix REL-MR- 24DC/21-21/MS Single Relay (Part No: 2987943 ) offers a 24 V DCnominal input voltage UN, 19.2 V DC ... 52.8 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/21-21/MS |
Phoenix REL-MR- 24DC/21-21/MS Single Relay – Technical Specifications
| Specification | Value |
|---|---|
| Product type | Single relay |
| Mechanical service life | 5x 106 cycles |
| Service life electrical | see diagram |
| Maximum power dissipation for nominal condition | 0.43 W |
| Test voltage (Winding/contact) | 5 kV AC (50 Hz, 1 min., winding/contact) |
| Test voltage (Changeover contact/changeover contact) | 5 kV AC (50 Hz, 1 min., changeover contact/changeover contact) |
| Nominal input voltage UN | 24 V DC |
| Input voltage range | 19.2 V DC ... 52.8 V DC |
| Drive and function | monostable |
| Drive (polarity) | non-polarized |
| Typical input current at UN | 18 mA |
| Typical response time | 9 ms |
| Typical release time | 6 ms |
| Contact switching type | 2 changeover contacts |
| Type of switch contact | Single contact |
| Contact material | AgNi |
| Maximum switching voltage | 250 V AC/DC |
| Minimum switching voltage | 12 V (at 10 mA) |
| Limiting continuous current | 8 A |
| Maximum inrush current | 16 A (20 ms) |
| Min. switching current | 10 mA (at 12 V) |
| Interrupting rating (ohmic load) max. | 2000 VA (for 250 V AC) |
| Connection method | Plug / solder connection |
| Width | 12.7 mm |
| Height | 29 mm |
| Depth | 25 mm |
| Ambient temperature (operation) | -40 °C ... 70 °C |
| Ambient temperature (storage/transport) | -40 °C ... 85 °C |
| Standards/regulations | EN 61810-1 |
| Switching capacity | 1 A (at 24 V, DC13) |
| Motor load according to UL 508 | 1/4 HP, 120 V AC (N/O contact) |
The Phoenix Contact REL-MR-24DC/21-21/MS (Part No: 2987943) is a durable Phoenix Plug-in Miniature Relay engineered for precise control and efficient performance in automation panels. It operates at a nominal voltage of 24 V DC and supports an extended input range from 19.2 V DC to 52.8 V DC, ensuring stable operation under variable supply conditions. With a quick response time of 6 ms and a typical input current of 18 mA, this Single Relay delivers accurate and consistent switching even in time-sensitive logic circuits.
Constructed with AgNi contact material, the REL-MR-24DC/21-21/MS offers high conductivity and excellent resistance to wear, handling continuous currents up to 8 A and switching voltages of 250 V AC/DC. It features a mechanical service life of 5 × 10⁶ cycles, ensuring long operational reliability in demanding applications. With a compact 12.7 mm width and 25 mm depth, it provides space-saving installation for densely packed control panels. Designed to perform from -40 °C to +70 °C, this Single Relay ensures consistent function across industrial, commercial, and environmental conditions. Rated for 2000 VA switching capacity and tested to EN 61810-1 standards, it’s a trusted component for high-performance electrical interface systems.
The Phoenix Contact REL-MR-24DC/21-21/MS is widely used in PLC interface circuits, machine control modules, signal switching panels, and HVAC automation systems. Engineers prefer this Single Relay for its fast switching, long mechanical life, and plug-in connection design that simplifies installation and maintenance. It performs reliably in both low-voltage and high-resistance load circuits, supporting efficient electrical isolation and signal feedback. With a rugged enclosure and stable electrical behavior, it’s suitable for use in production equipment, process monitoring, and power distribution boards. Maintenance teams value its precision, durability, and consistent thermal stability, making it ideal for OEM projects and long-duration industrial applications.
Professionals searching for REL-MR-24DC-21-21-MS-2987943, REL-MR-24DC/21-21/MS, or Phoenix Contact 2987943 rely on the consistent performance of Phoenix 2987943 technology. This 2987943 Phoenix relay combines compact design with stable response, delivering precise control in automation environments. The REL MR 24DC 21 21 series offers efficiency and durability, ensuring smooth operation in control systems and signal interfaces. Built on advanced design principles, the Phoenix Contact REL-MR-24DC/21-21/MS continues to be a preferred choice for engineers and technicians seeking reliable, high-speed relay solutions for 24 V DC industrial automation setups.
