Phoenix Contact 2987985 REL-MR-24DC/21-21AU/MS Single relay

The REL-MR- 24DC/21-21AU/MS is a Phoenix Contact plug-in miniature relay with 2 changeover contacts featuring multi-layer AgNi hard gold-coated contacts for reliable low-level signal switching. It operates on a 24 V DC coil and integrates a status LED, mechanical switching position indicator, test button, and freewheeling diode in a compact 12.7 mm wide housing. Mechanical service life is rated at 5x10^6 cycles.

Technical specifications:

• Part designation: REL-MR- 24DC/21-21AU/MS
• Catalog number: 2987985
• Manufacturer: Phoenix Contact
• EAN: 4046356480994
• Product type: Single relay, plug-in miniature relay
• Nominal input voltage: 24 V DC
• Input voltage range: 19.2 V DC - 52.8 V DC
• Typical input current at UN: 18 mA
• Drive: monostable, non-polarized
• Contact configuration: 2 changeover contacts
• Contact material: AgNi, hard gold-plated
• Max switching voltage (gold contact): 30 V AC / 36 V DC
• Limiting continuous current (gold contact): 50 mA
• Max switching voltage (after gold wear): 250 V AC/DC
• Limiting continuous current (after gold wear): 8 A
• Switching capacity: 1.5 A (at 240 V, AC15)
• Test voltage (winding/contact): 5 kV AC (50 Hz, 1 min.)
• Max power dissipation: 0.43 W
• Typical response time: 9 ms / release time: 6 ms
• Mechanical service life: 5x10^6 cycles
• Connection method: Plug / solder connection
• Dimensions (W x H x D): 12.7 mm x 29 mm x 25 mm
• Weight (excl. packing): 18.41 g
• Ambient temperature (operation): -40°C - 70°C
• Ambient temperature (storage/transport): -40°C - 85°C
• Pack size: 10 pc
• Country of origin: CN

Features and benefits:

• Integrated freewheeling diode protects DC circuits from coil de-energization voltage spikes
• Hard gold-coated contacts enable switching of signals as low as 1 mA at 12 V
• Status LED and mechanical position indicator allow visual diagnostics without test equipment
• Test button provides detectable manual operation for commissioning and fault isolation
• Wide input voltage tolerance (19.2 V DC - 52.8 V DC) accommodates supply fluctuations
• ISA-S71.04 G3 Harsh Group rated for use in corrosive gas environments

Applications:

• Low-level signal switching in PLC output circuits and industrial control panels
• Interface relay coupling 24 V DC control signals to field devices and actuators
• Automation cabinets in process control, building automation, and machine control
• Installations in harsh or corrosive environments requiring G3-rated components

Compliant with EN 61810-1, EN 50178, and VDE 0435-201. Approved to UL Recognized and cUL Recognized (File E 195083), EAC (RU*C-DE.*08.B.00010), and VDE approval of drawings. Fulfills EU RoHS substance requirements. Compatible mandatory relay bases: RIF-1-BPT/2X21 (item 2900931, push-in) and RIF-1-BSC/2X21 (item 2900930, screw connection).

Also known as: Phoenix Contact REL-MR- 24DC/21-21AU/MS, Phoenix 2987985, Phoenix Contact 24VDC 2CO miniature relay, PC relay 2987985.