Components are fixed in place with fixed wiring.
Examples: XL-21, GGD (and earlier types such as PGL).
Each circuit is made into a drawer unit that plugs into the vertical busbar and can be replaced while energized.
Examples: GCK, GCS, MNS.
XL-21 Power Cabinet
Typical Applications:
Terminal power and lighting distribution cabinets for floors and workshops, usually installed against the wall.
Meaning of Letters (common explanation):
X: Box-type (distribution box, box structure).
L: Power (Load).
21: Series number (the 21st design series).
Cabinet Features:
Narrow cabinet body, shallow depth, with multiple rows of miniature circuit breakers, fuses, and contactors on the inside of the front door; terminal blocks at the bottom.
Simple structure and low cost—suitable for centralized distribution of small-capacity power and lighting loads.
GGD Distribution Cabinet
Typical Applications:
Incoming, sectionalizing, outgoing-feeder, capacitor cabinets, and other main low-voltage distribution applications in power distribution rooms.
Meaning of Letters (common explanation):
G (1): Cabinet-type, AC low-voltage distribution cabinet.
G (2): Fixed installation and fixed wiring (fixed type).
D: For power distribution.
Cabinet Features:
Fixed-type structure with an upper instrument compartment, a middle section for the main circuit breaker, and a lower cable/busbar compartment.
One of the most widely used general-purpose fixed distribution cabinets, with high cost performance and many manufacturers.
Typical Applications:
Early-generation Chinese withdrawable cabinet system, commonly used for PC (Power Center) and MCC (Motor Control Center).
Meaning of Letters:
G: Enclosed switchgear.
C: Withdrawable (Cassette / Withdrawable).
K: Control Center.
Cabinet Features:
Top horizontal busbar compartment, front drawer functional units, rear vertical busbar + cable compartment.
Drawer height is typically based on a 200 mm module, offering flexible configuration. One of the earlier domestic withdrawable cabinet designs.
Typical Applications:
One of the mainstream withdrawable cabinet types in China, widely used in power plants and industrial facilities for PC + MCC systems.
Meaning of Letters (industry explanation):
G: Enclosed switchgear.
C: Withdrawable.
S: System / design series code (named by the joint design team; no strict official Chinese meaning).
Cabinet Features:
Enhanced thermal and dynamic stability, improved compartmentalization, and higher drawer density compared with GCK.
Top horizontal busbar, high-density drawer area at the front, and vertical busbar + cable compartment at the rear.
Suitable for applications with many loads, high short-circuit levels, and frequent maintenance.
Typical Applications:
Modular low-voltage switchgear system, widely used in data centers, petrochemical plants, rail transit, and other high-demand environments.
Letter Meaning:
MNS Module “E” and Drawer Specifications:
The modular unit E = 25 mm. Within each 8E (200 mm) height unit, the width can also be divided into multiple drawer positions:
8E Drawer: 8E = 8 × 25 = 200 mm height
16E Drawer: 400 mm height
24E Drawer: 600 mm height
8E/4: Four small drawers within the same 8E height
8E/2: Two drawers within the same 8E height
Two mainstream modular systems exist:
E = 20 mm:
Typically used in GCS and similar systems with KS profiles. Hole spacing is based on a 20 mm grid; drawer heights are adjusted accordingly (e.g., 8E = 160 mm, etc.).
E = 25 mm:
Typically used in MNS with C-profiles. Common front functional area heights are 8E (200 mm), 16E, 24E, and a total functional height of 72E (1800 mm).
Cross-section similar to the letter “C,” enclosed on three sides with one open side.
Commonly used with the 25 mm module, typical in MNS/GCK-type frames.
A special multi-fold cabinet frame profile with perforations on all sides for flexible assembly.
Commonly used with the 20 mm module, typical for GCS-type withdrawable cabinets.
I am Frank, Electrical Engineer in AISIKAI Team. I will share technical articles on Switches, Circuit Breakers and other electrical devices. With 10 years of electric project experience, I am commited to provide professional electrical solutions.
