Mitsubishi Relay Terminal Block MR-TB20

The Mitsubishi MR-TB20 is a dedicated relay terminal block designed for use with a wide range of Mitsubishi programmable logic controllers (PLCs), including the MELSEC FX series and others requiring relay output expansion. It serves as an interface unit between the PLC's relay output module and the field wiring for connected load devices.

Key Features and Specifications:

* Model: MR-TB20

* Type: Relay output terminal block (connector type).

* Number of Points: 20 points. It typically provides terminals for 20 independent output circuits.

* Compatible Connectors: Designed to connect directly to the output connector of corresponding Mitsubishi PLC relay output units (e.g., models ending with -ES, -ESS, -EYR, etc.), using a matching cable or direct mounting where applicable.

* Terminal Structure: Features screw terminals for secure connection of field wiring (load side wires). Each terminal is clearly numbered for easy circuit identification and wiring.

* Rated Specifications: The terminal block itself is a passive wiring interface. The electrical ratings (voltage, current) are determined by the relay contacts inside the connected PLC output module. Common supported ratings for the associated relays are typically up to 250V AC/30V DC and 2A per point.

* Indicators: Often includes LED indicators (one per point) that show the ON/OFF status of each output relay, facilitating visual troubleshooting.

* Mounting: Can be mounted on a standard DIN rail (35mm width) for easy installation inside control panels.

* Primary Function: Simplifies wiring by providing a centralized, labeled terminal point for all output connections. It protects the PLC's output connector from direct wire stress and allows for easier maintenance and wire management.

* Common Applications: Used to connect and control various AC/DC loads such as contactors, solenoid valves, indicator lamps, and small motors in industrial automation systems, machine control, and building automation.

Typical Usage:

The MR-TB20 is installed on a DIN rail. A cable from the PLC's relay output module plugs into one side of the terminal block. The wires leading to the field devices (loads) are then connected to the corresponding screw terminals. The status LEDs provide immediate feedback on the output commands from the PLC.