What is a YRDMY-J / YRDMCY-J Cable?
C-5 PVC Round Cable Highly Flexible for Energy Guiding Chains
The YRDMY-J and YRDMCY-J cables represent cutting-edge solutions in industrial power transmission and control applications. These highly flexible PVC round cables are specifically engineered for demanding dynamic environments, including energy guiding chains (cable carriers) and festoon systems. Manufactured by Anhui Feichun Special Cable Co., Ltd., these cables combine durability, flexibility, and reliability to meet the rigorous requirements of modern industrial operations.
The designation “YRDMY-J” refers to unscreened power and control cables, while “YRDMCY-J” indicates screened variants with electromagnetic interference (EMI) protection. Both types feature Class 5 flexible copper conductors and are designed to withstand millions of bending cycles in continuous-flex applications.
1. Purpose and Applications
Primary Application: Energy Guiding Chains (Cable Carriers)
Energy guiding chains, also known as cable carriers or drag chains, are mechanical systems that organize and protect cables in dynamic applications. The YRDMY-J and YRDMCY-J cables are specifically optimized for these systems, where cables must undergo constant longitudinal movement and repetitive bending cycles.
Key Application Benefits:
- Continuous Flex Performance: Designed for travel speeds up to 150 m/min with minimal mechanical stress
- Long Service Life: Short lay pitch construction enables millions of bending cycles
- Space-Efficient Design: Compact outer diameter reduces chain size requirements
- Reliable Power Delivery: Maintains electrical integrity under constant movement
Secondary Application: Festoon Trolleys and Systems
Festoon systems use suspended cable carriers that travel along horizontal tracks to power mobile equipment. These cables excel in festoon applications due to their abrasion-resistant sheath, flexible construction, and ability to handle the unique mechanical stresses of suspended operations.
Cranes & Material Handling
Standard indoor cranes, process cranes, overhead cranes, and mobile lifting equipment requiring reliable power supply during operation.
Agricultural Systems
Irrigation systems, automated farming equipment, and mobile agricultural machinery with dynamic cable requirements.
Industrial Automation
Handling equipment, rack feeders, automated storage systems, and robotic applications requiring continuous-flex cables.
Manufacturing Equipment
Machine tools, production lines, conveyor systems, and any application with moving components requiring power and control.
2. Key Characteristics and Technical Advantages
Advanced Design Features
🔄 Twist-Free Stranding Technology
Prevention of corkscrews: Conductors are stranded with reverse twist lay, eliminating the tendency to spiral or corkscrew during flexing operations. This critical design feature extends service life and prevents premature failure.
💪 Center Stress Relief Element
Enhanced load capacity: Cables with 5 or more conductors incorporate a central stress relief element that distributes mechanical loads evenly across the cable structure, enabling higher tensile load-bearing capacity (15 N/mm² during operation).
🛡️ Abrasion-Resistant PVC Sheath
Extended durability: Specialized bending-resistant PVC compound provides exceptional resistance to mechanical wear, chemical exposure, and environmental degradation while maintaining flexibility.
📏 Short Lay Pitch Construction
Superior flex life: Short lay pitch (tight stranding) reduces stress on individual conductors during bending, dramatically increasing cycle life compared to standard cables.
🔌 Core-to-Sheath Bonding
Structural integrity: Filler materials create tight bonding between cores and outer sheath, preventing core migration and maintaining cable roundness throughout its service life.
📡 EMI Protection (YRDMCY-J)
Screened variants: Braided copper screen with 85% coverage provides excellent electromagnetic interference protection for sensitive control and signal applications.
Mechanical Performance Characteristics
| Parameter | Specification | Significance |
|---|---|---|
| Minimum Bending Radius | 7.5 × cable diameter (∅) | Tight bending capability for compact chain systems |
| Travel Speed | Up to 150 m/min | Suitable for fast-moving industrial equipment |
| Tensile Load-Bearing Capacity | 15 N/mm² during operation | Withstands dynamic mechanical stress without damage |
| Conductor Flexibility Class | Class 5 (DIN VDE 0295) | Highly flexible stranded copper for continuous-flex applications |
3. Material Structure and Construction
Layer-by-Layer Cable Construction
🔧 Conductor Design
Material: Bare electrolytic copper (oxygen-free, high conductivity)
Flexibility Class: Class 5 according to DIN VDE 0295 / IEC 60228
Construction: Fine multi-wire stranded design for maximum flexibility
Purpose: Provides excellent electrical conductivity while maintaining flexibility for millions of bending cycles
🎨 Core Insulation
Material: Polyvinyl chloride (PVC) compound
Color Coding:
- Up to 5 conductors: Standard colors (brown, black, gray, blue, green/yellow)
- 6+ conductors: Black cores with white numbering plus green/yellow earth conductor
Standards: Color coding per VDE 0293-308
🌀 Stranding Configuration
Up to 7 conductors: Layer stranding with reverse twist and short lay pitch
8 to 12 conductors: Bundle stranding with reverse twist, short lay, and inner sheath over core bundle for maximum core stability
13+ conductors: Bundle stranding with additional filler materials and reinforced inner sheath
Benefit: Reverse twist eliminates cable rotation (corkscrewing) during flexing
⚡ Electromagnetic Shielding (YRDMCY-J Only)
Shield Type: Braided bare copper wires
Coverage: Approximately 85% optical coverage
Purpose: Protects against electromagnetic interference (EMI) and radio frequency interference (RFI)
Application: Essential for sensitive control systems and data transmission in electrically noisy environments
🛡️ Outer Sheath
Material: Special high-quality bending-resistant PVC compound
Color: Black (opaque) for UV protection
Properties:
- Exceptional abrasion resistance
- Oil-resistant formulation
- UV-resistant for outdoor applications
- Flame retardant and self-extinguishing
- CFC-free and LBS-free/silicone-free composition
Cable Designation Code Explanation
YRDMY-J / YRDMCY-J Designation Breakdown:
Y = Insulation material: PVC (Polyvinyl Chloride)
RD = Cable shape: Round (Rund)
M = Cable type designation
C = Shield: Braided copper wires (only in YRDMCY-J)
Y = Sheath material: PVC
J = With green/yellow earth conductor
Example: YRDMY-J 5 G 2.5
= PVC insulated, round, PVC sheathed cable with 5 conductors (including earth), 2.5 mm² cross-section
4. Compliance with International Standards
Primary Standards Compliance
| Standard | Description | Compliance Aspect |
|---|---|---|
| DIN VDE 0250 | Power cables with rated voltages | Cable design, construction, and performance requirements |
| DIN VDE 0295 | Conductors of insulated cables | Class 5 flexible conductor specifications |
| DIN VDE 0298-3 | Application of cables – Tensile loads | Tensile load-bearing capacity during operation (15 N/mm²) |
| DIN VDE 0298-4 | Application of cables – Current-carrying capacity | Ampacity ratings at specified ambient temperatures |
| IEC 60228 | Conductors of insulated cables | International standard for Class 5 flexible conductors |
| IEC 60332-1 | Flame propagation test for single cables | Flame retardant and self-extinguishing properties |
| DIN VDE 0482-265-2-1 | Fire behavior of cables | Equivalent to IEC 60332-1 for flame retardancy |
| UL/CSA | North American safety standards | UL and CSA compliant for North American markets |
| DESINA | German industrial standards organization | Recognized by German industrial standards |
Flame Retardant Performance
IEC 60332-1 Flame Test Requirements:
The cable is mounted vertically and exposed to a standardized flame for 60 seconds. To pass the test:
- The cable must self-extinguish after the flame is removed
- Fire damage must remain at least 50mm below the upper mounting clamp
- The cable does not propagate flame along its length
This ensures that in the event of fire, the YRDMY-J and YRDMCY-J cables will not contribute to flame spread, providing critical safety in industrial environments.
5. Electrical Parameters and Safety Thresholds
Voltage Ratings
| Cable Type | Rated Voltage Uo/U | Max AC Operating Voltage | Max DC Operating Voltage |
|---|---|---|---|
| YRDMY-J (Unscreened) | 600/1,000 V | 700/1,200 V | 900/1,800 V |
| YRDMCY-J (Screened) | 300/500 V | 318/550 V | 413/825 V |
| Note: Uo = Voltage between conductor and earth; U = Voltage between conductors | |||
Temperature Ratings and Limits
| Operating Condition | Temperature Range | Safety Consideration |
|---|---|---|
| Flexing Operation | -5°C to +80°C | Normal dynamic operation range |
| Fixed Installation | -15°C to +80°C | Stationary installation range (lower cold limit) |
| Maximum Conductor Temperature | +70°C | Continuous operation limit – do not exceed |
| Short-Circuit Temperature | +150°C | Maximum allowable temperature during fault conditions (brief duration only) |
⚠️ Critical Safety Threshold:
Never exceed +80°C ambient temperature during operation. Operating beyond this threshold can cause:
- Premature insulation degradation
- Reduced electrical performance
- Shortened service life
- Potential safety hazards
Current-Carrying Capacity (Ampacity)
The ampacity values (IB) listed in the technical specifications are based on:
- Ambient temperature of 30°C
- Cables laid on an even, flat support
- 100% duty cycle (continuous operation)
Ampacity Adjustment Factors:
The actual current-carrying capacity must be adjusted based on:
- Ambient temperature: Higher temperatures require derating
- Installation method: Bundled cables generate more heat
- Duty cycle: Intermittent operation may allow higher currents
- Cable grouping: Multiple cables in proximity reduce capacity
Consult DIN VDE 0298-4 derating tables for specific installation conditions.
Electrical Testing Requirements
| Test Type | YRDMY-J | YRDMCY-J |
|---|---|---|
| AC Test Voltage | 2.5 kV | 2.0 kV |
| Test Duration | 5 minutes between conductors and earth | |
| Pass Criteria | No breakdown or flashover during test period | |
6. Detailed Technical Specifications
YRDMY-J Control Cables (Unscreened)
| Type | Conductors × Cross-section | Outer Diameter (mm) | Weight (kg/100m) | Ampacity (A) | Tensile Load (N) |
|---|---|---|---|---|---|
| 1.5 mm² Cross-section | |||||
| YRDMY-J | 4 G 1.5 | 7.0 – 7.6 | 10.5 | 18.0 | 90 |
| YRDMY-J | 5 G 1.5 | 8.2 – 8.8 | 12.5 | 15.3 | 110 |
| YRDMY-J | 7 G 1.5 | 9.6 – 10.4 | 17.0 | 11.3 | 160 |
| YRDMY-J | 12 G 1.5 | 14.4 – 15.4 | 35.8 | 9.5 | 270 |
| YRDMY-J | 18 G 1.5 | 17.0 – 18.0 | 50.0 | 8.5 | 400 |
| YRDMY-J | 25 G 1.5 | 20.5 – 21.7 | 68.0 | 7.2 | 560 |
| 2.5 mm² Cross-section | |||||
| YRDMY-J | 4 G 2.5 | 8.8 – 9.4 | 15.0 | 26.0 | 150 |
| YRDMY-J | 5 G 2.5 | 9.4 – 10.2 | 18.0 | 22.1 | 190 |
| YRDMY-J | 7 G 2.5 | 11.7 – 12.5 | 25.2 | 16.4 | 260 |
| YRDMY-J | 12 G 2.5 | 17.3 – 18.3 | 53.9 | 13.8 | 450 |
| YRDMY-J | 18 G 2.5 | 22.2 – 23.8 | 83.3 | 12.2 | 675 |
| YRDMY-J | 25 G 2.5 | 24.8 – 26.4 | 104.0 | 10.4 | 940 |
YRDMY-J Power Cables (4-Core, 5-Core, and 7-Core)
| Type | Conductors × Cross-section | Outer Diameter (mm) | Weight (kg/100m) | Ampacity (A) | Tensile Load (N) |
|---|---|---|---|---|---|
| 4-Core Power Cables | |||||
| YRDMY-J | 4 G 4 | 10.5 – 11.3 | 23.0 | 34.0 | 240 |
| YRDMY-J | 4 G 6 | 12.6 – 13.4 | 33.8 | 44.0 | 360 |
| YRDMY-J | 4 G 10 | 15.6 – 16.6 | 53.6 | 61.0 | 600 |
| YRDMY-J | 4 G 16 | 19.3 – 20.9 | 85.4 | 82.0 | 960 |
| YRDMY-J | 4 G 25 | 24.2 – 25.8 | 131.0 | 108.0 | 1,500 |
| YRDMY-J | 4 G 35 | 27.4 – 29.0 | 178.5 | 135.0 | 2,100 |
| 5-Core and 7-Core Power Cables | |||||
| YRDMY-J | 5 G 4 | 11.5 – 12.3 | 26.9 | 28.9 | 300 |
| YRDMY-J | 7 G 4 | 13.8 – 14.6 | 36.3 | 21.4 | 420 |
| YRDMY-J | 7 G 6 | 16.8 – 17.8 | 56.0 | 27.7 | 630 |
YRDMCY-J Screened Control Cables
| Type | Conductors × Cross-section | Outer Diameter (mm) | Weight (kg/100m) | Ampacity (A) | Tensile Load (N) |
|---|---|---|---|---|---|
| YRDMCY-J | 4 G 1.5 C | 9.1 – 9.7 | 15.3 | 18.0 | 60 |
| YRDMCY-J | 5 G 1.5 C | 9.7 – 10.3 | 17.6 | 15.3 | 75 |
| YRDMCY-J | 7 G 1.5 C | 12.4 – 13.2 | 26.8 | 11.3 | 105 |
| YRDMCY-J | 12 G 1.5 C | 16.7 – 17.7 | 44.1 | 9.5 | 180 |
| YRDMCY-J | 18 G 1.5 C | 19.8 – 21.0 | 60.8 | 8.5 | 270 |
| YRDMCY-J | 25 G 1.5 C | 23.3 – 24.9 | 88.1 | 7.2 | 375 |
Note: “G” indicates inclusion of green/yellow protective earth conductor. “C” indicates copper braided screen.
7. Precautions for Use and Installation Guidelines
Installation Planning and Design
⚠️ Pre-Installation Assessment
Before installing YRDMY-J or YRDMCY-J cables, conduct a thorough assessment of:
- Travel distance: Determine maximum cable length required
- Travel speed: Ensure application stays within 150 m/min limit
- Acceleration forces: Low to medium forces are suitable for these cables
- Environmental conditions: Temperature, UV exposure, chemical presence, humidity
- Bending radius: Ensure energy chain design allows minimum 7.5× cable diameter
- Tensile loads: Calculate expected loads and verify they remain below 15 N/mm²
Handling and Storage
Proper Handling Techniques:
- Avoid sharp bends: Never bend cable tighter than 7.5× diameter even during installation
- Protect from damage: Prevent crushing, impact, or abrasion during transport and storage
- Storage conditions: Store in dry location at temperatures between -15°C and +40°C
- Coil orientation: Maintain drum orientation to prevent cable twist during unwinding
- UV protection: While sheath is UV-resistant, avoid prolonged direct sunlight exposure during storage
Installation Best Practices
🔧 Energy Chain Installation:
- Cable Selection: Choose appropriate conductor count and cross-section based on power requirements and mechanical loads
- Chain Sizing: Select energy chain with internal dimensions providing adequate clearance (typically 10-20% larger than cable bundle)
- Bending Radius: Configure chain with radius ≥ 7.5× cable diameter – larger radii increase service life
- Cable Separation: Use dividers in chain to prevent cable-to-cable abrasion when running multiple cables
- Strain Relief: Install proper strain relief at both fixed and moving connection points
- Length Calculation: Account for additional cable length needed for chain movement (typically travel distance + radius calculations)
- Laying Direction: Install cables in neutral position (half-extended chain) to minimize pre-stress
🏗️ Festoon System Installation:
- Carrier Spacing: Position festoon carriers at appropriate intervals to prevent excessive cable sag
- Cable Support: Use smooth-surfaced saddles or carriers to prevent sheath abrasion
- Sag Management: Allow controlled sag between carriers – not too tight (excess tension) or too loose (excessive movement)
- End Connections: Provide adequate strain relief and weather protection at termination points
- Track Alignment: Ensure festoon track is straight and level to prevent binding
- Weight Distribution: Balance cable weight across carriers for smooth operation
Electrical Installation Precautions
⚡ Electrical Safety Requirements:
- Voltage verification: Confirm operating voltage matches cable rating (600/1000V for YRDMY-J, 300/500V for YRDMCY-J)
- Proper grounding: Connect green/yellow earth conductor to protective earth at both ends
- Screen termination (YRDMCY-J): Ground copper screen at one end only to prevent ground loops (typically at supply end)
- Ampacity verification: Ensure actual load current does not exceed rated ampacity for installation conditions
- Termination quality: Use appropriate cable glands, properly sized to cable diameter
- Circuit protection: Install overcurrent protection (fuses or circuit breakers) sized per cable ampacity
- Isolation: De-energize system before installation or maintenance work
Environmental Considerations
| Condition | Suitability | Precautions |
|---|---|---|
| Indoor Use | ✓ Excellent | Primary application – no special precautions needed |
| Outdoor Use | ✓ Good (UV-resistant) | Provide weather protection at connection points; consider additional UV shielding for extreme sun exposure |
| Humid Environments | ✓ Good | Cable is moisture-resistant; ensure proper sealing at terminations |
| Oil Exposure | ✓ Good (oil-resistant) | PVC sheath resists mineral oils and hydraulic fluids commonly found in industrial settings |
| Chemical Exposure | ⚠ Limited | Not suitable for strong acids, alkalis, or solvents – consult manufacturer for specific chemicals |
| Low Temperature | ⚠ Limited below -5°C (flexing) | PVC becomes stiff below -5°C – not recommended for flexing applications in extreme cold |
Maintenance and Inspection
Regular Maintenance Schedule:
- Visual inspection: Monthly examination for sheath damage, abrasion, or deformation
- Mechanical check: Quarterly assessment of cable movement, checking for binding or excessive wear
- Electrical testing: Annual insulation resistance testing (recommended 1000V megger test)
- Connection inspection: Semi-annual check of terminations for looseness or corrosion
- Chain/carrier inspection: Regular examination of energy chain or festoon carrier condition
- Documentation: Maintain inspection records and note any degradation trends
⚠️ Replacement Criteria:
Replace cable immediately if any of the following conditions are observed:
- Visible conductor exposure through damaged sheath
- Severe abrasion (>25% sheath thickness reduction)
- Insulation resistance below 1 MΩ
- Permanent cable deformation or kinking
- Broken or severed conductors
- Heat damage or melting of sheath
- Contamination by incompatible chemicals
8. Common Problems and Troubleshooting
Problem 1: Premature Cable Failure
| Symptom | Likely Cause | Solution |
|---|---|---|
| Cable breaks after short service life |
• Bending radius too small • Excessive travel speed • Improper installation |
• Verify chain radius ≥ 7.5× cable ∅ • Check travel speed ≤ 150 m/min • Review installation procedures |
| Conductor breakage at connections |
• Inadequate strain relief • Excessive tensile load • Vibration at termination |
• Install proper strain relief devices • Reduce load or use heavier cable • Secure termination points firmly |
| Sheath cracking or splitting |
• Temperature below -5°C during flexing • Chemical contamination • Ozone exposure |
• Provide heating or insulation • Protect from incompatible chemicals • Limit ozone exposure |
Problem 2: Corkscrewing or Cable Twisting
Description:
Cable develops spiral twist or corkscrew shape during operation, potentially causing jamming in energy chain or excessive wear.
Causes:
- Incorrect cable installation with pre-twist
- Using standard (non-reverse-lay) cables instead of YRDMY-J/YRDMCY-J
- Improper unwinding from drum during installation
- Chain design forcing rotation
Prevention/Solution:
- Verify cable is genuine YRDMY-J/YRDMCY-J with twist-free stranding
- Install cable in neutral position without pre-twist
- Unwind cable properly from drum (don’t roll drum on ground)
- Check energy chain design allows free movement without rotation
- Replace with properly designed cable if corkscrewing persists
Problem 3: Electromagnetic Interference (EMI)
| Symptom | Likely Cause | Solution |
|---|---|---|
| Control signal errors or noise |
• Using unscreened YRDMY-J in EMI environment • Screen not properly grounded • Screen grounded at both ends (ground loop) |
• Upgrade to screened YRDMCY-J cable • Verify screen connection to protective earth • Ground screen at supply end only |
| Equipment malfunction near VFDs |
• Power and control cables in same chain • Inadequate separation • High-frequency switching noise |
• Use chain dividers to separate power/control • Use YRDMCY-J screened cables • Install ferrite filters if necessary |
Problem 4: Overheating
Description:
Cable becomes excessively hot during operation, potentially leading to insulation damage or premature failure.
Causes:
- Current exceeds rated ampacity for installation conditions
- Inadequate heat dissipation in enclosed energy chain
- Ambient temperature above design limits (+80°C max)
- Multiple cables bundled without derating
- Poor connections causing high resistance
Solutions:
- Measure actual conductor temperature – must not exceed +70°C
- Reduce load current or upgrade to larger conductor size
- Apply derating factors per DIN VDE 0298-4 for bundled cables
- Improve ventilation in energy chain if possible
- Check and tighten all terminations
- Consider forced cooling if ambient temperature is high
Problem 5: Water Ingress at Terminations
Description:
Moisture enters cable at connection points, causing insulation resistance degradation or corrosion.
Prevention:
- Use weather-rated cable glands with proper IP rating (IP65 or higher for outdoor)
- Install glands correctly with appropriate compression
- Apply cable entry sealing compound or heat-shrink boots
- Position connection boxes with cable entries facing downward
- Regularly inspect seals and glands for degradation
Remedy if Water Ingress Occurs:
- De-energize circuit immediately
- Remove water and dry cable thoroughly
- Test insulation resistance before re-energizing
- Replace cable if insulation resistance below 1 MΩ
- Improve sealing before returning to service
Problem 6: Reduced Service Life
| Observation | Contributing Factors | Improvement Actions |
|---|---|---|
| Cable life shorter than expected |
• High acceleration/deceleration rates • Frequent starts and stops • 24/7 continuous operation |
• Reduce acceleration rates if possible • Use larger bending radius • Schedule periodic replacement based on cycles |
| Excessive sheath wear |
• Abrasive environment • Sharp edges in chain • Contamination with abrasive particles |
• Clean chain regularly • Inspect for sharp edges and remove • Consider additional protective sleeving |
| Inconsistent failure patterns |
• Poor quality installation • Mixing cable types • Non-genuine replacement cables |
• Use only trained installers • Use consistent cable specifications • Source cables from authorized suppliers |
9. Selection Guide: When to Use YRDMY-J vs. YRDMCY-J
Choose YRDMY-J (Unscreened) When:
- Application is primarily power transmission (motors, heaters, lighting)
- EMI environment is minimal
- Higher voltage required (up to 1000V)
- Cost optimization is priority
- No sensitive control or data signals present
Choose YRDMCY-J (Screened) When:
- Application involves sensitive control signals
- Near variable frequency drives (VFDs) or motor controllers
- EMI/RFI protection is critical
- Control automation or PLC systems involved
- Mixed power and signal cable routing
10. Quality Assurance and Certification
Anhui Feichun Special Cable Co., Ltd. Quality Commitment:
All YRDMY-J and YRDMCY-J cables undergo rigorous quality control and testing procedures:
- 100% electrical testing: Every cable length tested for conductor continuity, insulation resistance, and voltage withstand
- Mechanical testing: Sample batch testing for tensile strength, bending cycles, and abrasion resistance
- Flame retardant certification: IEC 60332-1 compliance verified by independent testing laboratories
- Material verification: Incoming inspection of raw materials ensures consistent quality
- Manufacturing controls: ISO-certified production processes with continuous monitoring
- Traceability: Every cable reel marked with production date, batch number, and specifications
Conclusion
The YRDMY-J and YRDMCY-J cables from Anhui Feichun Special Cable Co., Ltd. represent advanced engineering solutions for demanding continuous-flex applications. Their specialized construction featuring twist-free stranding, short lay pitch, bending-resistant PVC sheath, and center stress relief elements ensures exceptional durability and reliability in energy guiding chains and festoon systems.
Compliance with international standards including DIN VDE 0250, IEC 60332-1, and IEC 60228 guarantees these cables meet the highest safety and performance requirements. Whether powering cranes, material handling equipment, irrigation systems, or industrial automation, these cables deliver consistent performance across millions of bending cycles.
For optimal results: Select the appropriate cable type (unscreened YRDMY-J or screened YRDMCY-J), properly size conductors based on current requirements, install with adequate bending radius (≥7.5× cable diameter), and follow manufacturer’s installation and maintenance guidelines. Regular inspection and adherence to operating parameters will ensure maximum service life and safe operation.
