Products - Annunciator Relays and Illuminated Annunciator Relays MR
Annunciator Relays MR 11, MR 21, MRE 11 and MRE 21
Annunciator Relay MR 11
The MR 11 annunciator relay is used for the indication of danger and alarm situations and operational states. Its miniature size (39 x 46 mm ground surface) makes it suitable to be combined in large numbers so that the entire relay assembly can be used for alarm and status signalling in control rooms, control panels and mimic diagrams.
Construction:
The MR 11 is a semi-automatic relay which can be switched
in N/C or N/O mode. The required switch action - N/C or N/O - is set in the
factory prior to delivery, according to customer order specifications.
Subsequent modifications can be carried out by the manufacturer.
Apart from the coil excitation voltage, no other auxiliary voltage is required for visual signal indication. This is a valuable feature particularly in those applications where the relay has the task of monitoring voltages.
Function:
The entire indicator flag area is black when the relay is in
its normal mode and ready for operation (optional: grey RAL 7037 indicator
flag for relay assemblies). As soon as the relay picks up, the indicator flag
becomes visible (white field with written characters). At the same time, the
contacts move into their working position. Operating the reset button situated
immediately below the indicator flag panel acknowledges the message. The
indicator remains visible, but now an additional flag with red-white shaded
lines appears. At the same time, the contacts return to their normal position.
The relay’s flag area automatically returns to its normal status upon
elimination of the fault situation.
Apart from the operation described above, it is also possible to actuate the contacts directly from the pallet system, that means they are independent from the acknowledgement.
Annunciator Relay MR 21
Just like the MR 11, the MR 21 annunciator relay is used for the indication of danger and alarm situations and operational states. Ist miniature size (39 x 46 mm ground surface) makes it suitable to be combined in large numbers so that the entire relay assembly can be used for alarm and status signalling in control rooms, control panels and mimic diagrams.
Function:
Unlike the MR 11 relay, the MR 21 annunciator relay is fully
automatic. It has no manual reset button and no NO/NC changeover facility.
Depending on the preset contact mode (N/O or N/C operation) the relay picks
up either at energization or at deenergization. The contacts operate and the
mechanical indicator flag is set. Upon return to normal of the fault situation
the indicator flag is automatically acknowledged and the contacts return to
their normal position.
Ground-fault Annunciator Relay MRE 11
The MRE 11 annunciator relay is a semi-automatic relay used for the indication of earth leakage faults in three-phase networks.
Function:
The relay is equipped with two windings and must be connected
to the open delta winding of a displacement transducer. The relay picks up at
30 Va.c. This has the effect of adding the second winding into the relay
circuit which protects the relay against overload at a voltage increase up to
100 V a.c. The MRE 11 ground-fault annunciator relay is also available for
other voltage ranges. Operation and indication method of the MRE 11 relay are
the same as for the MR 11 relay described opposite.
Ground-fault Annunciator Relay MRE 21
The MRE 21 is a fully-automatic annunciator relay for the indication of ground leakage faults in three-phase networks.
Function:
The MRE 21 is based on the same principle of operation as
the MRE 11 relay. Only difference: as the MRE 21 is fully-automatic it has no
manual reset button, nor is it equipped with a change-over facility for N/O
or N/C operation.
Annunciator Relays MR11, MRE11, MR21, and MRE21