Rated voltage:
Main circuit: AC 380V / 660V (50Hz)
Auxiliary circuit: AC 220V/380V, DC 24V/48V/110V/220V
Rated insulation voltage: AC 660V / 750V / 1000V
Rated current:
Horizontal bus (main bus): usual range 630A - 6300A (common levels are 800A, 1250A, 1600A, 2000A, 2500A, 3150A, 4000A，5000A,6300A).
Vertical busbar (distribution busbar/feeder busbar): Typically range 400A - 1600A (common levels 630A, 800A, 1000A, 1250A, 1600A).
Functional unit (drawer) rated current:
Power/feeder unit: Typically 16A - 630A (or higher to 1250A, depending on the circuit breaker frame).
Motor control unit: Typically ≤ 315A (commonly used to control ≤160kW motors).
Rated short-time withstand current (Icw):
Horizontal busbar: Typically 30kA, 50kA, 65kA (effective value) / 1s.
Vertical busbar: Typically 30kA, 50kA (effective value) / 1s.
Functional unit: Depends on the breaking capacity of the circuit breaker or fuse installed inside.
Rated peak withstand current (Ipk): Usually 2.2 times of Icw (e.g. Icw=50kA, Ipk≈110kA).
Breaking capacity: Determined by the circuit breaker (MCCB, MCB) or fuse combination switch (F-C circuit) installed in the cabinet. Common MCCB breaking capacity is 35kA, 50kA @400V.
Protection level:
Cabinet: IP30, IP40 (in accordance with GB 4208/IEC 60529). IP40 is a common basic requirement.
Functional unit (drawer) compartment: ≥ IP20 when the door is closed, IP00 when operating.
Internal isolation form (according to IEC/GB standards):
Common Form 2b, Form 3b.
Form 2b: The busbar system is isolated from the functional unit; the functional units are not isolated from each other.
Form 3b: The busbar system is isolated from the functional units; the functional units are also isolated from each other (safer, more expensive).
Standardized and modular design:
Adopting standard modulus (usually E=20mm or 25mm) design, the functional unit size is standardized (such as 1/2 unit, 1 unit, 1.5 unit, 2 units, 3 units).
The drawer height is unified (such as 160mm, 200mm, 320mm, etc.), which is convenient for arrangement, combination, expansion and maintenance.
Withdrawable functional unit:
Core features: The core electrical components (circuit breakers, contactors, thermal relays, etc.) of each circuit (feeding, motor control, etc.) are installed in independent withdrawable drawers.
Operating position: It has three clear positions: "connection position" (working position), "test position" (test position) and "separation position" (withdrawal position). Operated by crank or handle.
Primary connector: The main circuit adopts large-capacity, low-impedance plug-in contacts (moving and static contacts) to ensure reliable connection. Support hot plug (under certain conditions).
Secondary connectors: The control circuit adopts reliable plug-in connectors (aviation plugs) to facilitate debugging and replacement of drawers.
Compact structure and high space utilization:
The cabinet width is usually 600mm or 800mm, the depth is about 800mm or 1000mm, and the height is about 2200mm. A single cabinet can accommodate multiple drawer units.
The "cabinet frame + functional small room" structure is adopted, and the layout is reasonable.
The functional area is clearly divided and the safety is good:
The cabinet is usually divided into three parts: busbar room, functional unit room (drawer room), and cable room (outgoing line room), which are separated by metal partitions.
Interlocking mechanism: It has the basic "five protection" functions:
Prevent the drawer from being pulled out/inserted with load.
Prevent the circuit breaker from being opened or closed by mistake (the drawer cannot be closed when it is in the test/separated position).
When the drawer is in the connection position, the cabinet door cannot be opened (or opening is limited).
Prevent accidental entry into the live interval (partition protection).
Perfect grounding measures.
Economical and practical:
As a mainstream domestic cabinet type, it has a mature design and a complete industrial chain, and its manufacturing and procurement costs are more advantageous than imported brands (such as MDmax).
Convenient installation and maintenance:
Operation and wiring in front of the cabinet: All operations, monitoring, and wiring (primary and secondary) are completed in front of the cabinet, saving space.
Drawers can be quickly replaced: The fault circuit drawer can be pulled out for maintenance or replacement as a whole, greatly shortening the power outage time and improving system availability.
The cable room has sufficient space for easy wiring.
Flexible application:
It can be configured as a pure distribution cabinet (PC) or a motor control center (MCC), or a mixture of the two.
The drawer unit can be installed with a variety of components: molded case circuit breakers (MCCB), miniature circuit breakers (MCB), contactors, thermal relays, soft starters, instruments, indicator lights, buttons, etc.
It supports multiple input and output line modes such as top in and top out, top in and bottom out, bottom in and top out, and bottom in and bottom out.
