MDmax ST is an ABB-authorized low voltage switchgear featuring modular design, reliable performance, and high safety protection. It is widely used in power utilities, petrochemical plants, industrial and mining enterprises, and other fields.

Structural Design:
The cabinet adopts a modular structure. Its frame is constructed with double-folded aluminized zinc-coated steel sheets, with modular holes spaced at 25mm intervals. Horizontal and vertical assembly is achieved with precision bolts, making the structure robust, easy to assemble, and maintenance-free. The enclosure is treated with a powder coating process for enhanced durability. The top cover of the horizontal busbar compartment is removable for convenient busbar installation. The main busbar system is fully isolated from the functional units, cable compartment, and horizontal secondary wiring section, ensuring safe clearances.

Functional Configuration:
The system supports various functions including power distribution, reactive power compensation, and motor control center (MCC). It is available in both drawer-type and fixed partition designs. The drawer-type structure can accommodate up to 36 circuits, with three-position switching achievable without compromising the protection degree. All moving parts of the drawer have position alignment, and the drawer door and switch are equipped with mechanical interlocks to enhance operational safety.

Electrical Performance:
The main busbar supports a wide range of rated currents, from 400A to 6300A, with a short-time withstand current of up to 100kA/1s. The vertical busbar supports up to 2500A, meeting diverse power system requirements.

Safety Performance:
Compliant with IEC 61439-2 and GB 7251.2-2023, the cabinet has passed certifications including seismic test (IK09), internal arc fault test, salt spray resistance, and high-altitude adaptation. With a service life exceeding 30 years, the design ensures complete isolation between functional units. The enclosure protection level can reach up to IP54, effectively preventing foreign object ingress and electric shock risks, safeguarding both personnel and equipment.

Smart Features:
Incorporating cloud computing, big data, IoT, and smart sensors, the system supports remote monitoring, optimization, management, and predictive maintenance of power distribution systems through cloud platforms. Communication interfaces are reserved in each drawer unit, allowing for customized smart system design upon request.

Application Scenarios:
The MDmax ST can be used as a power distribution center, motor control center, or lighting and power control system. It is widely applied in industries such as new energy, lithium battery production, paper manufacturing, electronics and semiconductors, nuclear power, metro systems, petrochemicals, data centers, municipal engineering, and commercial buildings.

Technical Parameters

(A)
Rated Voltage (Un): 400V, 380V
Frequency (fn): 50Hz / 60Hz
Rated Insulation Voltage (Ui): 1000V (Incoming and Feeder Cabinets), 690V (Control Cabinets)
Rated Current of Main Busbar (InA): 1600A to 400A (50Hz)
- For ratings above 800A, the rated current at 60Hz is 95% of that at 50Hz
- For ratings of 800A and below, the rated current at 60Hz is the same as at 50Hz
Rated Short-Time Withstand Current of Main Busbar (Icw): 30kA
Rated Group Current of Distribution Busbar in Feeder Cabinet (Ing): 800A to 200A (50Hz)
- For ratings of 800A and below, the rated current at 60Hz is the same as at 50Hz
Rated Short-Time Withstand Current of Feeder Distribution Busbar (Icw): 30kA
Rated Group Current of Distribution Busbar in Control Cabinet (Ing): 800A to 200A (50Hz)
- For ratings of 800A and below, the rated current at 60Hz is the same as at 50Hz
Rated Short-Time Withstand Current of Control Cabinet Busbar (Icw): 30kA
Type (Indoor/Outdoor): Indoor
Mechanical Impact Protection (IK Rating): IK10
Enclosure Protection Degree (IP Rating): IP54, IP44, IP42, IP41, IP40, IP32, IP31, IP30

(B)
Rated Voltage (Un): 690V, 660V, 525V, 415V, 400V, 380V
Rated Frequency (fn): 50Hz / 60Hz
Rated Insulation Voltage (Ui): 1000V
Rated Current of Main Busbar (InA): 4000A to 1600A (50Hz)
- At 60Hz, rated current is 95% of the 50Hz rated value
Rated Group Current of Feeder Cabinet Distribution Busbar (Ing): 1500A to 1000A (50Hz)
- At 60Hz, rated current is 95% of the 50Hz rated value
Rated Group Current of Control Cabinet Distribution Busbar (Ing): 2500A to 400A (50Hz)
- For ratings above 800A, 60Hz current is 95% of the 50Hz rating
- For ratings 800A and below, 60Hz current is the same as 50Hz
Rated Short-Time Withstand Current of Main Busbar (Icw): 80kA
Rated Short-Time Withstand Current of Feeder Busbar (Icw): 65kA
Rated Short-Time Withstand Current of Control Busbar (Icw): 65kA
Type (Indoor/Outdoor): Indoor
Enclosure Protection Degree (IP Rating): IP54, IP42, IP41, IP40, IP30
Mechanical Impact Protection (IK Rating): IK10

(C)
Rated Voltage (Un): 400V, 380V
Rated Frequency (fn): 50Hz / 60Hz
Rated Insulation Voltage (Ui): 1000V (Incoming and Feeder Cabinets), 690V (Control Cabinets)
Rated Current of Main Busbar (InA): 6300A to 4000A (50Hz)
- At 60Hz, the rated current is 95% of the 50Hz value
Rated Short-Time Withstand Current of Main Busbar (Icw): 100kA
Rated Group Current of Feeder Cabinet Distribution Busbar (Ing): 4300A to 2500A (50Hz)
- At 60Hz, the rated current is 95% of the 50Hz value
Rated Short-Time Withstand Current of Feeder Busbar (Icw): 65kA
Rated Group Current of Control Cabinet Distribution Busbar (Ing): 2000A to 400A (50Hz)
- For ratings above 800A: 60Hz current = 95% of 50Hz value
- For ratings 800A and below: 60Hz current = 50Hz value
Rated Short-Time Withstand Current of Control Busbar (Icw): 50kA
Type (Indoor/Outdoor): Indoor
Enclosure Protection Degree (IP Rating): IP42, IP41, IP40, IP30