Nidec Control Techniques MP900A4 / MP900A4R (900A) Overview

Nidec Control Techniques MP900A4 / MP900A4R (900A) Overview

The Nidec MP900A4 and its regenerative counterpart, the MP900A4R, represent the high-capacity tier of the Mentor MP series.

These are advanced DC thyristor drives designed to provide robust power control for large industrial motors.

By integrating the control technology from Nidec’s Unidrive SP series, these drives offer AC-like performance and flexibility within a DC framework.

Technical Parameter Table

Product Advantages and Features

Regenerative Braking: The MP900A4R version allows for full 4-quadrant operation, feeding energy back into the grid during deceleration,

which significantly increases energy efficiency in high-inertia applications.

High Intelligence: Features an onboard PLC (SyPTLite) and the ability to add high-speed “Solutions Modules” for motion control and expanded I/O.

Field Control: Includes an integrated field controller as standard, reducing the need for external components for most motor frames.

Safety Integrated: Features a “Safe Torque Off” (STO) function, meeting modern industrial safety standards (SIL3/PLe).

Retrofit Friendly: Designed to easily replace older Mentor II units or other legacy DC drives with minimal mechanical adjustment.

Application Cases

Metal Processing: Controlling heavy-duty rolling mills and wire drawing machines where high torque at low speed is critical.

Crane and Hoist: Utilizing the regenerative capabilities of the MP900A4R for controlled lowering and energy recovery.

Extruders: Providing precise speed regulation for plastic and rubber extrusion lines to ensure product consistency.

Pulp and Paper: Managing section drives in paper mills that require high synchronization and reliability.

Optional FXMP25 external field controller for current fields up to 25A

Digital link for field control from Mentor MP or Mentor II

Standalone digital control mode for simple application

Flux control for enhanced open loop performance

Intelligent field weakening

Field forcing – for high dynamic machine reversal

Field reversal – low dynamic machine reversing using two quadrant main stack

Mentor MP has a field control mode for fields requiring greater than 25A

Serial port for Modbus RTU and PC communications

3 Universal option module slots, allowing Mentor MP to benefit from the solutions developed for Control Techniques market leading AC drive technology.

Each option slot allows:

High performance PLC and motion control

Ethernet and Fieldbus communications

Connectivity to additional feedback devices

Additional I/O

Galvanically isolated control

Smartcard for drive parameter back-up and copying, allowing rapid installation and maintenance

Integrated PLC as standard

Standard software features for easy integration

PID controller

Motorised potentiometer

Digital lock (Slave operation from master encoder)

Open loop control using estimated speed advanced processing based on armature voltage and field flux feedback

Unique Product Description: The “Legacy Bridge”

The MP900A4 is often referred to as the “Legacy Bridge” in the automation world.

It is unique because it allows facilities with massive, expensive DC motors to achieve “Industry 4.0” connectivity and precision without the multi-million dollar cost of switching to AC motors and gearboxes. It bridges the gap between 20th-century heavy iron and 21st-century digital control.

Installation and Maintenance

Cooling: Ensure a minimum clearance of 100mm above and below the unit. These high-current units generate significant heat and require forced-air ventilation.

Galvanic Isolation: Always use high-speed semiconductor fuses (aR type) to protect the thyristor power bridge.

Maintenance: Periodically check the torque on power terminal connections, as thermal cycling can loosen bolts over time. Inspect cooling fans for dust buildup every 6 months.

Related & Other Models in the Same Series

The Mentor MP series scales significantly to meet different industrial demands: