Electric chain hoists (code Q20102) are lightweight lifting equipment consisting of an electric motor, transmission mechanism, and chain wheel. Rated capacity typically ranges from 0.1 to 60 tons, with lifting heights of 3-120 meters.

I. Scope and Basic Terminology

This standard applies to electric chain hoists used in:

• General working environments
• Molten metal handling operations

Not applicable in environments with:

• Explosive gases
• Combustible dust
• Corrosive atmospheres

Safety clutch: A mechanical device in the transmission system that transfers torque through friction and slips under specified overload conditions.

II. Types and Basic Parameters

Classifications by travel mechanism:

• Stationary Electric Chain Hoists
  • Suspension type
  • Support type
• Traveling Electric Chain Hoists
  • With running mechanism along tracks
• Basic Parameters
  • Working class M1-M8 (GB/T3811-2008)

III. Technical Requirements

• Operating Environment

• Power supply: 110V-690V AC (single/three-phase), 50/60Hz
• Voltage fluctuation: ≤10%
• Temperature range: -20℃ to +40℃ (general use) -20℃ to +60℃ (molten metal handling)
• Humidity: ≤50% at 40℃
• Maximum altitude: 1000m

• Performance Requirements

• Static load capacity: 4× rated load
• Hook rotation: 360° horizontal
• Brake slip: ≤v/100 (v = stable lifting distance in 1min)
• Speed tolerance: ±10% lifting, -10%~25% lowering
• Minimum hook clearance: Not exceeding nominal value
• For molten metal: ≤16t capacity, minimum M6 duty class

IV. Safety and Health Requirements

• Safety Devices

• Travel limit switches
• Hook safety latch (except molten metal handling)
• Overload protection
• Emergency stop
• Insulation resistance: ≥1Ω
• Ground resistance: ≤0.1Ω
• Noise level: ≤78dB (<1t) or ≤83dB (≥1t)

• Special Requirements for Molten Metal Handling

• Dual limit protection
• Additional safety brake for >5t capacity
• Chain safety factor: ≥6.3
• Class F motor insulation minimum

V. Major Components

• Load Chain

• Material: ≥20CrMnTi
• Hardness: ≥52HRC
• Chain guidance system required

• Electric Motor

• Protection class: ≥IP54
• Duty cycles: S2, S3, S4, or S5
• Control voltage: ≤50V

VI. Marking, Packaging, Transport, and Storage

Required nameplate information:

• Manufacturer
• Product name and model
• Serial number
• Rated capacity
• Working class
• Lifting height/speed
• Motor specifications
• Standard number