The MR 21 annunciator relay is used to indicate dangerous states and operating states. It is fully automatic.
Drop indicator relay for indicating danger and operating states
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 MR 11 annunciator relay is a semi-automatic relay. Apart from the coil excitation voltage, no other auxiliary voltage is required for the visual display. This is particularly important in voltage monitoring applications
Your advantages Recognize system states at a glance
✔ Time-saving commissioning with preconfigured messages
✔ Reliable and durable operation with the robust construction
✔ Predefined contact assignments for numerous applications
How the drop indicator relays work Semi and fully automatic design versions
Semi-automatic drop indicator relays
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.
Fully automatic drop indicator relays
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.
Marking labels Flexible messages for your system
The messages or indicator flags on the marking labels can be created individually to meet your requirements. Using preconfigured messages enables even faster commissioning.
The standardized plates also enable one or two-line printing, each with up to 15 characters.
The well-designed construction also enables the subsequent replacement of printed marking plates. They therefore remain flexible in use even after many years of operation.
Mounting methods Easy mounting in the control cabinet front or on the DIN rail
Combine drop indicator relays easily Ideal overview with front installation
Our combination housings allow you to easily mount up to nine drop indicator relays in the control cabinet front. The common carrier does not only simplify mounting, but also simplifies the overview of any messages present.
Depending on combination housing, up to four or up to nine drop indicator relays can be mounted. Naturally, you can also install fewer relays than the maximum. In this case, the remaining free slots are simply closed off with dummy plates. This means that you have the option of extending your system at a later date.