Product Overview

　　The MDmax-ST cabinet is a new product developed by ABB based on years of design and manufacturing experience. Our company is one of the main authorized manufacturers of this cabinet type in East China.

　　The frame of the MDmax-ST low-voltage switchgear adopts double-folded aluminum-zinc plated sheet technology, with modular holes arranged at 25mm intervals. The cabinet frame is convenient to assemble and exceptionally sturdy. The shell is made of electroplated and powder-coated steel plate, ensuring the highest durability. The door panel, top plate, back plate, partition, and side plates are installed with self-tapping screws. The product has three functional units: drawer type, movable type, and plug-in type; the drawer type structure can accommodate up to 36 units; without reducing the protection level, three-position switching of the drawer circuit can be achieved.

　　The MDmax-ST low-voltage switchgear adopts a modular structure in its design. By selecting standard components and standard parts, the compactness, diversity, and flexibility of the cabinet assembly scheme are realized. It can be combined into different types of switchgear according to requirements, such as fixed type, fixed partition type, and drawer type. In terms of function, it considers power distribution, reactive power compensation, motor control center (MCC), AC frequency converter, soft starter, etc.

　　The MDmax-ST low-voltage switchgear has the characteristics of multi-functionality and modularity, so it is suitable for low-voltage power distribution systems in various occasions.

Operating Conditions

　　The MDmax-ST low-voltage switchgear should be used under the following conditions to ensure its normal operation.

　　1. The ambient air temperature should not exceed +40℃ and not be lower than -5℃, and the average temperature within 24 hours should not exceed +35℃.

　　2. The air is clean. When the highest temperature is +40℃, the relative humidity should not exceed 50%. At lower temperatures, higher relative humidity is allowed, such as 90% at +20℃.

　　3. The altitude should not exceed 2000m.

　　4. If the above operating conditions cannot be met, the user and the manufacturer should negotiate a solution.

Main Technical Parameters and Production Standards

　　1. Rated operating voltage

　　Main circuit: 400V

　　Auxiliary circuit: AC 230V, 400V

　　DC 110V, 220V, 24V

　　2. Rated frequency: 50Hz

　　3. Rated current Main busbar up to 6300A

　　Distribution busbar up to 2000A

　　4. Protection level IP30-IP54

　　5. Partition type 1-4b

MDmax-ST Features

　　1. Frame structure

　　The frame of the MDmax-ST switchgear adopts a self-supporting frame structure, which is assembled from double-folded G-shaped sections.

　　Modular holes are arranged on the frame at intervals of 25mm, making the cabinet frame convenient and exceptionally sturdy. The entire frame is precisely connected by horizontal and vertical bolts, and the frame structure is maintenance-free. The frame, partitions, and mounting plates are all made of aluminum-zinc plated sheet.

　　2. Shell

　　The shell of the MDmax-ST switchgear is made of electroplated and powder-coated steel plate, ensuring the highest durability. The door panel, top plate, back door, partition, and side plates are installed with self-tapping screws, and the final cabinet structure is determined according to the protection level requirements. Based on the requirements of the conventional safety system, small rooms or compartments used for debugging, operation, and maintenance are all equipped with their own independent door panels, and the protection level can range from IP30 to IP54.

　　3. Functional compartments of the switchgear

　　The switchgear is divided into four parts: a Busbar compartment

　　b Functional unit compartment

　　c Cable compartment

　　d Secondary control wire horizontal wiring area

　　4. Switchgear dimensions (unit mm)

　　5 Busbar system

　　5.1 The main busbar is located at the top of the switchgear (in the busbar compartment). The current rating of the busbar can be selected as single, double, or triple, and the busbar compartment can be expanded as needed. For easy installation of the busbar on site, the top cover of the busbar compartment can be removed. The main busbar system installed at the top of the switchgear is completely separated from the functional unit area, cable area, and secondary wire horizontal wiring area, ensuring sufficient safety distance between the busbar and the operating and maintenance personnel.

　　5.2 Grounding protection bar

　　The grounding protection bar is installed at the bottom rear of the switchgear, and the PE bar is fixed to the frame to ensure electrical continuity.

　　5.3 Distribution busbar

　　A 3-pole or 4-pole distribution busbar system can be centrally arranged and isolated with a distribution busbar cover. The busbar cover has ventilation holes and can be independently removed from the rear of the cabinet for easy heat dissipation, thereby improving the current-carrying capacity of the distribution busbar and facilitating regular inspection and maintenance.

　　6-drawer unit

　　Drawers can be easily replaced while the device is running, ensuring the continuity of electrical equipment.

　　6.1 Small drawers

　　Small drawers are available in 1/4 unit and 1/2 unit sizes.

　　This series of drawers is compactly designed. The smallest 1/4 unit (U) can accommodate up to 36 units, thus minimizing the overall number of switch cabinets and maximizing space saving. This series of drawers consists of fixed and movable parts (connectors). After pushing the drawer's fixed part into the switch cabinet unit compartment, close the unit compartment door. Insert the rocker to sequentially switch the drawer's movable part between the isolated, test, and connected positions. An LED indicator window displays the connector's position status.

　　Operating Instructions:

　　a. Press the drawer unlock button, push in the drawer, and close the component door.

　　b. Rotate the rocker clockwise to sequentially switch between the isolated, test, and connected positions. The position indicator window will display the current connection status.

　　c. When the rocker is in the connected position, remove the rocker, move the moving button to the left to close the rocker hole, and close the main switch.

　　d. After the main switch is turned off, move the moving button to the right, insert the rocker, and rotate it counterclockwise to exit from the connected, test, and isolated positions sequentially.

　　e. After opening the unit component door, press the drawer unlock button to remove the small drawer.

　　6.2 Full-width drawer

　　This series of drawers comes in four heights: 1U/1.5U/2U/3U (U=200mm). This series of drawers consists of fixed and movable parts (connectors). After pushing the drawer's fixed part into the switch cabinet unit compartment, close the unit door. Insert the rocker to sequentially switch the drawer's movable part between the isolated, test, and connected positions. An LED indicator window displays the connector's position status.

　　Regardless of whether the switch inside the drawer is manually or electrically operated, the drawer panel and switch have a mechanical interlocking mechanism. That is, regardless of whether it is a manual or electric scheme, the drawer component door cannot be opened as long as the switch is in the closed position.

　　All drawer operations do not require opening the door, and the protection level is not compromised during the three-position switching.

　　Operating instructions for manual on/off drawers:

　　a. Open the unit door, push the drawer along the guide rails, and close the unit door.

　　b. Press the unlock button, rotate the rocker clockwise to the test position, and the unlock button will pop up and reset.

　　c. Press the unlock button again, rotate the rocker clockwise to the connected position, and the unlock button will pop up and reset.

　　d. Remove the rocker, move the unlock moving button to the left, which will simultaneously close the rocker hole and lock the unlock button. The main switch can then be closed.

　　e. After the main switch is turned off, move the moving button to the right, press the unlock button, insert the rocker, rotate it counterclockwise from the connected position to the test position, and the unlock button will pop up and reset.

　　f. Press the unlock button again, rotate the rocker counterclockwise to the isolated position, and the unlock button will pop up and reset.

　　g. Remove the rocker, open the unit door, lift the drawer locking handle upwards, and remove the drawer.

　　6.3 Electrically operated drawers

　　Remote control functionality is achieved by adding an electric operating mechanism to the molded case circuit breaker, which also provides perfect electrical interlocking functionality. That is, the drawer can only be moved when the circuit breaker is in the off state.

　　Operating instructions for electrically operated drawers:

　　a. Open the unit door, push the drawer along the guide rails, and close the unit door.

　　b. Press the unlock button, rotate the rocker clockwise to the test position, and the unlock button will pop up and reset.

　　c. Press the unlock button again, rotate the rocker clockwise to the connected position, and the unlock button will pop up and reset.

　　d. Remove the rocker, move the unlock moving button to the left, which will simultaneously close the rocker hole and lock the unlock button.

　　e. Now press the electric operating mechanism closing button to close the main switch.

　　f. After the main switch is turned off by the electric operating mechanism, move the moving button to the right, the rocker hole will open, and the unlock button will be released.

　　g. Press the unlock button, insert the rocker, rotate it counterclockwise from the connected position to the test position, and the unlock button will pop up and reset.

　　h. Press the unlock button again, rotate the rocker counterclockwise to the isolated position, and the unlock button will pop up and reset.

　　i. Remove the rocker, open the unit door, lift the drawer locking handle upwards, and remove the drawer.

　　j. If a mistake is made, that is, the main switch is not turned off, and the rocker hole is not closed. If you want to remove it from the connected position, you must press the unlock button, which will trigger the main switch to turn off, ensuring that the drawer can only be moved when the main switch is off.

　　7. Fixed partition unit

　　When the functional unit current is large, to ensure the reliability of the connector, plug-in or pull-out switches are selected. By effectively partitioning each functional unit compartment, the convenience and safety of operation and maintenance are ensured. Standard unit height: 150/200/300/400/600mm.