MDS3 Series

Automatic Transfer Switch

The MDS3 Series Automatic Transfer Switch adopts a DC coil drive and is widely applied in critical end-use loads across various industries, such as commercial buildings, hotels, shopping centers, fire protection, hospitals, paper manufacturing, metallurgy, petrochemicals, airports, highways, railways, and subways. The MDS3 Series is dedicated to providing simple and compact solutions to ensure smooth switching between end power sources.


Controller Features:

  • No additional control power supply required

  • Processor and digital circuits are isolated from the primary circuit

  • Programmable I/O ports to meet customer application needs

  • Real-time monitoring of three-phase voltage and frequency of both power sources

  • Real-time monitoring of various ATS parameters and statuses

  • Large LCD display (128x64) for real-time display of power sources and ATS parameters/status

  • Electrical parameters, time delays, and control functions can be freely set via the LCD panel

  • Event logging and data statistics functions

  • RS485 communication interface; supports Modbus RTU protocol for integration with power monitoring and fire control systems

  • Generator start/stop and scheduled test functions

  • Real-time self-diagnosis


Features and Advantages:

  • Load utilization category: AC-33A, suitable for mixed loads

  • Switching action time <100ms

  • Mechanical latching with built-in mechanical interlock

  • Neutral line capacity equal to phase line capacity; equipped with independent arc-extinguishing chamber

  • Excellent short-time withstand current and making capacity

  • Available in 2-position and 3-position versions; the 3-position includes an intermediate “0” position for isolation

  • Multiple operation modes: auto-transfer auto-recovery / mutual standby / auto-transfer manual recovery / manual / remote signaling / test

  • Multiple switching modes: automatic / electric / manual mechanical switching

  • Supports fire protection interlock features including “no-switching” during fire, fire isolation, and remote fire control


Product Range:

  • Rated current: 16A–3200A

  • Rated voltage: 208V / 220V / 230V / 240V / 380V / 400V / 415V

  • Poles: 2-pole / 3-pole / 4-pole

  • Frequency: 50Hz / 60Hz

  • Applicable for: Utility-to-Utility, Utility-to-Generator scenarios