Model Coding Standard for MWD / MWC / KWD / KWC Underground Hydraulic Excavators

Consistent formal industrial English style, standardized mining certification & machinery terminology, optimized logical structure, eliminated fragmented expression, matched the format of previous equipment brochures.

1. Compilation Reference Basis

All model coding rules strictly follow the coal industry standard MT/T 154.1 issued by the China Mining Products Safety Approval and Certification Center (aqbz.org).
Two core safety certification grades are applicable to underground mining equipment:

• MA: For gassy coal mine working environments
• KA: For metal & non-metal mine working environments

1.1 Definition of Standard Alphabet Codes

1.2 Official Definition of Four Main Product Series

1. MWD Series: Explosion-proof Electric Crawler Excavator for Coal Mines (MA Certified)
2. MWC Series: Explosion-proof Diesel Crawler Excavator for Coal Mines (MA Certified)
3. KWD Series: Slim Low-Profile Electric Excavator for Metal Mines (KA Certified)
4. KWC Series: Slim Low-Profile Diesel Excavator for Metal Mines (KA Certified)

1.3 Standard Model Naming Format for Certification Filing

Unified coding formula:
MW / KW – Operating Weight (t) / Bucket Capacity (m³) L (Modified Code)
Coding Rules:

1. Operating weight value is placed in front, followed by bucket volume;
2. The sequence is fixed and unified for official safety certificate registration and filing.

1.4 Standard Model Examples & Interpretation

1. MWD6/0.3L: 6-ton explosion-proof electric excavator for coal mines, equipped with a 0.3 m³ standard bucket
2. MWD6/0.3L(A): Upgraded variant with rotating working arm, with updated certification documents
3. MWC7/0.35L: 7-ton flameproof diesel excavator, suitable for long inclined coal roadways
4. KWD12/0.4L: 12-ton slim electric excavator for narrow-section metal mine tunnels
5. KWD4.1/0.2L: 4.1-ton mini narrow-body diesel excavator for ultra-restricted metal mine working faces
6. MWD2/0.12L: 2-ton ultra-mini electric excavator for small-scale coal excavation roadways

1.5 Core Differences Between Series & Certification Requirements

1. MWD (Coal Mine Electric Type, MA Certification Mandatory)

Fitted with zero-emission explosion-proof electric motors that fully comply with GB3836 explosion-proof standards, specially developed for high-gas coal roadways.
MA safety marking is a compulsory requirement before underground deployment. The machine operates on 660V / 1140V explosion-proof power cables.

2. MWC (Coal Mine Diesel Type, MA Certification Mandatory)

Equipped with National IV flameproof diesel engines complete with spark arrestors. It realizes cable-free free movement, ideal for long-distance tunneling and inclined shaft construction.
Operation is forbidden in environments with excessive methane concentration. The entire electrical system passes full MA certification.

3. KWD (Metal Mine Electric Type, KA Certification Mandatory)

Adopts an ultra-slim low-profile body design with outstanding trafficability, tailored for non-gassy metal mines. Only KA safety certification is required. Clean electric power supports uninterrupted long-hour excavation operations.

4. KWC (Metal Mine Diesel Type, KA Certification Mandatory)

Compact narrow-body diesel excavator free from external power supply limitations. It is widely used for metal mine wall trimming, roadway floor leveling and roadway reconstruction projects. Only KA safety marking is required for legal underground use.