Wire Rope Electric Hoists of the CD (standard duty) and MD (heavy duty) series dominate global material handling with their unparalleled blend of robust construction, operational reliability, and exceptional value. Engineered to rigorous Chinese GB/T standards yet recognized worldwide, these versatile hoists deliver efficient lifting across manufacturing plants, warehouses, construction sites, and repair facilities. Their modular design, dual-speed control, and proven safety features make them the go-to solution for loads from 0.5 to 80 tons.
Dual-Speed Precision Control
CD Series: Standard 8/0.8 m/min lifting speed for general material handling
MD Series: Enhanced 7/0.7 m/min lifting with reinforced components for intensive cycles
Micro-speed mode enables millimeter-accurate positioning
Robust Mechanical Design
CD Models: Aluminum alloy housing (lightweight) + Cast iron brake discs
MD Models: Ductile iron housing (impact-resistant) + Forged steel gears
Modular drum/gearbox assembly reduces maintenance downtime
Advanced Safety Systems
Dual electromagnetic brakes (primary + emergency)
Automatic overload limiter (110% cutoff)
Rotary limit switch with manual reset function
Phase protection relay prevents single-phasing damage
Table 1: CD vs MD Series Performance Comparison
| Parameter | CD Series | MD Series | Application Impact |
|---|---|---|---|
| Capacity Range | 0.5-20 tons | 5-80 tons | MD for foundries/steel mills |
| Duty Class | M3 (A3) – 150 starts/hr | M4-M5 (A4-A5) – 300 starts/hr | MD for high-frequency lifts |
| Lifting Speed | 8/0.8 m/min | 7/0.7 m/min | Smoter MD control for heavy loads |
| Sealing Class | IP54 | IP55/IP65 | MD for dusty/wet environments |
| Motor Insulation | Class F | Class H | MD withstands 180°C temps |
| Gear Hardness | HRC 50-55 | HRC 58-62 | MD resists pitting under shock loads |
Table 2: Standard Configuration Options
| Component | CD Standard | MD Standard | Upgrade Options |
|---|---|---|---|
| Control | Pendulum pendant | 8-button dustproof pendant | Radio remote (IP65) |
| Wire Rope | 6x19W-IWRC (1570MPa) | 6x36WS-IWRC (1770MPa) | Stainless steel (marine) |
| Mounting | Top hook | Trolley kit | Explosion-proof trolley |
| Safety | Overload limiter | Overload + Slack rope limiter | Load cell (RS485 output) |
Manufacturing Assembly
CD1-5D models (1-5t) for auto part positioning
Low headroom MD hoists in cramped workshops
Warehouse Logistics
CD 3-10t hoists on modular KBK rails
20m lifting height for high-bay storage
Heavy Industries
MD 32t hoists with cast steel hooks for slab handling
Foundry-grade MD hoists (heat shields + IP65)
Infrastructure Projects
Outdoor MD hoists (anti-corrosion coating)
80t capacity for bridge segment lifting
GB 3811-2008 Compliance
Dynamic load testing at 125% capacity
Static load testing at 150% capacity
Fail-Safe Braking System
Primary brake: Spring-loaded disc brake
Secondary brake: Centrifugal emergency brake
3-second descent prevention after power loss
Intelligent Protection
Real-time motor temperature monitoring
Voltage fluctuation tolerance: ±10%
Rope rewind guidance system
Energy Efficiency: IE3 premium motors reduce power consumption by 15% vs. legacy hoists
Lifecycle Durability: 50,000+ cycles (CD) / 100,000+ cycles (MD) at rated capacity
Maintenance Optimization:
Grease-lubricated gears (2-year service intervals)
Modular motor/gearbox replacement (30-min swap)
Self-diagnostic control panels
Capacity & Duty Cycle
Choose CD when: Loads ≤20t, starts <150/hr (A3 duty)
Choose MD when: Loads >5t, starts >200/hr (A4-A5 duty)
Environmental Factors
| Condition | Recommended Series | Special Requirements |
|---|---|---|
| Dusty (wood/grain) | MD with IP65 | Anti-static rope |
| Corrosive (chemical) | MD 316 stainless | Epoxy-coated electricals |
| High temp (>40°C) | MD Class H insulation | Thermal imaging port |
Control Requirements
Standard workshops: Pendant control (8m cable)
Hazardous zones: Explosion-proof radio remote (Ex d IIC T4)
Automated systems: CANopen interface + PLC integration
Daily Checks
Brake responsiveness test (no-load)
Rope inspection for kinks/corrosion
Monthly Maintenance
Brake clearance measurement (adjust to 0.5-0.7mm)
Gearbox oil level check
Annual Overhaul
Rope replacement (per 3-year schedule)
Load testing with certified weights
Insulation resistance test (min 1MΩ)
Smart Hoisting 4.0
IoT sensors for predictive maintenance
Bluetooth load data transmission
Green Technologies
Regenerative braking energy recovery
Solar-compatible DC models
Enhanced Safety
AI anti-sway systems
Collision avoidance radar
Conclusion: The Unmatched Value Proposition
CD and MD wire rope electric hoists deliver 20% lower lifetime costs than European equivalents while meeting ISO 4301, FEM 9.511, and GB 3811 standards. With capacities spanning 0.5-80 tons and duty cycles up to A5 (M5), they remain the most cost-effective lifting solution for value-driven operations. Their modular architecture ensures future upgrades – from radio controls to smart monitoring – protecting investments for decades.
