SAFETY LOCKOUT LOGIC RELAY MVAA14B1AA0785C
The MVAA14B1AA0785C of GEC ALSTHOM is a high-performance Auxiliary Relay, belonging to the Midos series.
Unlike the previously mentioned MVAJ operated relays, the MVAA series is mainly used for signal expansion, logic control, interlocking circuits, and contact point addition.
The following is the specific product information of this model:
Technical Specifications and Code Analysis Model Series: MVAA 14
Relay type: Electrical Reset type. This means that after the relay operates, it will be locked and the initial state can only be restored by energizing the reset coil.
Rated voltage ($V_x$) : 110/125V DC (code ‘B’). This applies to the DC operating power supply of the standard power system.
MVAA14B1AA0785C
Contact configuration: MVAA 14 is typically equipped with 4 pairs of contacts (commonly 4 normally open or mixed configurations, depending on the internal wiring). Reset method: The core feature of this model (MVAA 14) is that it is only electrically reset and usually does not come with a manual reset lever (different from MVAA 13). Installation Size: Midos Size 2 chassis
2. Core Functions and Applications
Contact Multiplication: When the number of output contacts of the main protection relay (such as a microcomputer protection device) is insufficient, or the contact capacity cannot directly drive a high-current circuit, MVAA is used as an intermediate link.
Electrical interlock/logic control: Due to its electrical reset function, it is often used in circuits that require “memory” of the state. For instance, after a fault occurs and a trip is triggered, the relay remains in the operated state until the operator remotely sends a reset instruction through the control system (DCS/ background).
High reliability: It adopts an attractive armature structure, which operates smoothly and features extremely high mechanical stability and shock resistance
Model, Reset Type, common uses
MVAA 11. Self Reset, instantaneous signal transmission, no memory required
MVAA 13. manual Reset (Hand Reset), on-site fault indication and locking
MVAA 14. Electrical Reset, Remote Logical Lockout and state Holding