The Mitsubishi MDS-DH-V1-20 is a proven servo amplifier of the MDS-DH series. It is used for the precise control of servo motors in CNC machine tools. With its robust design, high reliability and compact design, this model is particularly suitable for continuous operation in demanding production environments.
Device category: Servo Drive Unit
Series/Class: MDS-DH, 400-V class
Design: compact, forced-air cooled, service-friendly

MDS stands for Mitsubishi Drive System.
DH identifies the D-series with increased power density (High-Performance).
V1 describes a single-axis servo unit.
The number 20 stands for the power size of the 1 kW class.

The servo amplifier has all the typical connection terminals of the DH series. L1, L2, L3 are used for the mains connection (380–480 V AC), U, V, W for the connection of the servo motor. CN1 connects the drive unit to the CNC control, CN2 is provided for communication and diagnostics, CN3 for the encoder feedback of the motor. P and N form the DC bus connection to the power supply. The PE connection ensures safe grounding. The integrated 7-segment display shows operating states and error codes.

The MDS-DH-V1-20 is used in CNC lathes, milling centers, grinding machines and positioning axes. This drive shows its strengths especially in axes with high precision requirements. Thanks to the high dynamics, it is suitable for tool changers, linear units and feed drives with high repeat accuracy.

For a long service life, fans and heat sinks should be cleaned and checked regularly. Capacitors and power modules should be replaced preventively after several years of operation. Parameters and machine configurations should always be backed up before service work. Insulation measurements on the installed device should be avoided. A clean, low-resistance grounding is required.

When repairing the Mitsubishi MDS-DH-V1-20, a thorough initial inspection is carried out first, with a visual inspection and measurement of the DC intermediate circuit voltage. The condition of the display and LED signals is recorded. The unit is then completely disassembled, the assemblies are cleaned and the heat conduction connections are renewed. In the analysis process, the power section, gate control, capacitors and control board are checked. Defective or aged components are replaced, critical solder joints are reworked. After the repair, the functional test is carried out on the test bench with a reference servo motor. The current consumption, temperature profile and alarm thresholds are monitored. In the final long-term test, the unit runs for several hours under rated load before it is released with a complete test protocol and measurement report.