Phoenix Contact REL-MR-BL-12DC/21HC Single Relay – 12 V DC Coil, 1 Changeover Contact (SPDT), High Continuous Current, Plug-In Miniature Power Relay

Detailed Description:

The Phoenix Contact REL-MR-BL-12DC/21HC (Item No. 1109537) is a high-performance, plug-in miniature power relay designed for industrial control systems requiring compact, high-current switching in a basic housing. With a 12 V DC coil and a single changeover contact (SPDT), this module offers reliable switching of moderate loads while maintaining a small footprint

Key Features & Benefits:

• 12 V DC coil with input voltage range from 8.4 V DC to 27 V DC, allowing for flexible control-circuit tolerance. 

• 1 changeover contact (SPDT) which enables switching between common-normally closed and common-normally open paths. 

• High continuous current capability: Up to 16 A continuous current and able to handle inrush currents up to 30 A for 300 ms.

• Maximum switching voltage: Up to 250 V AC/DC for the contact side. 

• Compact size: Width around 12.7 mm, height 29 mm, depth 15.7 mm — ideal for high-density installations. 

• Rated for demanding duty: Designed for 100% operating factor, mechanical service life 10^7 cycles. 

• Plug-in mounting allows fast replacement and minimal downtime in control cabinets.

Typical Applications:

• Control-panel installations where space is limited but a reliable relay is required.

• Switching controllers, safety circuits, automation systems, interface between logic and higher-power loads.

• Upgrade or maintenance projects in industrial plant, machinery, machine tools, conveyors, etc.

Installation & Use Notes:

• Ensure coil voltage matches your control circuit (12 V DC) and wiring can support the input current (~33.3 mA). 

• Select appropriate base/socket for plug-in version (e.g., see compatible Phoenix Contact relay bases).

• Check contact ratings vs your load: For example, while it can handle 16 A continuous, ensure safe operation within ambient conditions, load type (resistive, inductive) and duty cycle.

• Mount in proper position, ensure contactor or relay environment does not exceed rated ambient temperature (-40 °C to +85 °C) and avoid excessive vibration or condensation. 

Scope of Delivery:
One (1) relay module, item number 1109537, as described.

Summary:
If you’re in search of a compact, high-quality plug-in miniature power relay for a 12 V DC control circuit with a single changeover contact capable of handling high continuous currents, the Phoenix Contact REL-MR-BL-12DC/21HC (1109537) represents an excellent solution in industrial automation applications.