MR11/MR21 Drop Indicator Relays

Drop indicator or annunciator relays are used as status indicators in control rooms, on control panels, and in mimic diagrams. Default contact assignments make rapid commissioning possible.

That is why semi-automated or fully automated design variants feature clearly arranged display surfaces. Their robust design ensures reliable operation, even under harsh ambient conditions.

The fully automatic drop indicator or annunciator relay MR 21 is also used to indicate dangerous states and operating states.

With this design version, message acknowledgment is automatic, without manual intervention. The device front therefore always displays the actual system state. The fully automatic design version is therefore ideal for personnel-free system operations.

The semi-automatic drop-indicator or annunciator relay MR 11 is used to display system states.

In this design version, message acknowledgment is performed manually by actuating the reset button mounted on the device front. This enables a clear overview of already known (acknowledged) or changed (not yet acknowledged) messages.

This allows service technicians on site to recognize whether system states are already known and whether appropriate measures have already been taken or whether measures still need to be taken. Upon acknowledgment and fault clearance, the drop indicator relay automatically returns to its original position.

The special feature of the semi-automatic design version is that the fault message on the front of the device is retained after fault clearance without prior message acknowledgment.

This enables the service technician to recognize whether uninterrupted system operation was possible, even after the fault has been cleared automatically.

• Time-saving commissioning with preconfigured messages
• Reliable and durable operation with the robust construction
• Predefined contact assignments for numerous applications