CY cable is a screened flexible control cable commonly used in industrial automation and control systems. If you’ve ever wondered what CY cable is, this simple guide explains the meaning, construction, installation best practices, and regulatory considerations—making it perfect for installers and specifiers alike.
Table of Contents
- What Is CY Cable? (CY cable meaning)
- CY vs SY vs YY – Quick Overview
- When to Use CY Cable
- Construction & Specifications
- CY Cable Installation Guide
- Standards & Compliance in the UK
- Maintenance & Troubleshooting
- Frequently Asked Questions
- Conclusion
What Is CY Cable?
CY cable is a multicore flexible cable featuring PVC insulation and an outer sheath, wrapped with a tinned copper braid—the “C” denotes copper screening, “Y” is PVC. The screen protects inner cores from electromagnetic interference (EMI), ensuring signal integrity in noisy environments.
Its flexibility (typically Class 5 conductors) makes it ideal for cable-chains or moving machinery, while the braid adds electrical screening without significantly increasing rigidity.
CY vs SY vs YY – Quick Overview
| Cable Type | Construction | EMI Protection | Mechanical Protection |
| YY | PVC insulated and sheathed | None | Light stress, indoors |
| SY | Same as YY, with steel braid | Minimal | Medium-to-high stress |
| CY | PVC + tinned copper braid | Excellent | Light-to-medium stress, EMI shielding |
In brief:
- YY cable: unscreened, flexible control cable.
- SY cable: steel-armoured, sturdier, limited EMI protection.
- CY cable: copper-screened, best for EMI-sensitive environments.
When to Use CY Cable
Choose CY cable when:
- Signal cables run close to power lines or switching devices.
- Applications involve PLCs, instrumentation, robotics, or milling machines.
- You need a flexible cable suitable for dynamic movement.
- Maintaining circuit integrity against EMI is critical.
Avoid CY cable for:
- Direct connection to mains.
- Fixed tray wiring or outdoor installations (use conduit if outdoor).
Construction & Specifications
A typical CY cable comprises:
- Class 5 fine-stranded copper conductors (flexible).
- PVC insulation and bedding, optionally LSHF.
- Tinned copper braid, 60-65% braid coverage for EMI protection.
- PVC outer sheath, often transparent or grey.
- Rated 300/500 V, temperature ranges vary: -5 °C to +70 °C (flex), -30 °C to +70 °C (static).
- Core counts commonly range 2–25+, available in colour-coded or numbered versions.
CY Cable Installation Guide
Follow this step-by-step guide to install CY cable correctly:
- Choose the right cable spec: Select size/core count based on current capacity and expected EMI exposure.
- Use correct glands: Fit EMC-rated cable glands—castle-style or braid-prep glands recommended.
- Terminate the braid: Fold back braid to the gland location; clamp evenly—do not pigtail.
- Ground screen properly: Connect screen to earth at the panel end; avoid floating screens or field-end connections.
- Mind the bending radius: Respect fixed minimum of 6× diameter; for flexing, 15×.
- Avoid UV exposure: Keep indoor or protected; outdoor needs conduit.
- Test after installation: Check continuity, insulation resistance, and earth-braid integrity.
Standards & Compliance in the UK
- CY cable isn’t a British Standard cable and lacks formal BS or EN standardisation—but CENELEC defines its type.
- According to BS 7671, use of CY cable in fixed installations is discouraged unless electrical safety equivalent is validated and documented.
- Always technically justify and certify its use as “departure from standard” when necessary.
Internal link: For broader cable types, see our Control Flex Cables guide.
External link: For regulatory context, visit IET’s BS 7671 guidance.
Maintenance & Troubleshooting
- Inspect sheath & braid regularly—replace if damaged or corroded.
- If intermittent signals occur, verify screen continuity and DB grounding.
- Check terminations after vibration or machinery movement.
- Clean earth connections to prevent contact resistance due to oxide build-up.
Frequently Asked Questions
1. What is CY cable used for?
CY cable is used for screened signal and control installations where EMI rejection and flexibility are essential—like robotics, CNC machines, and data control.
2. Is CY cable the same as SY cable?
No. SY cable has steel braid for mechanical protection, CY cable has copper braid for EMC. CY rejects interference; SY offers mechanical armour.
3. Can CY cable be used outside?
Only in conduit or protected enclosures. The PVC sheath isn’t UV resistant, and braid is not moisture sealed.
4. How do I terminate the braid on CY cable?
Fold braid back to the EMC gland, clamp evenly; avoid pigtailing—use brass or castle-style glands.
5. Does CY cable meet EN standards?
It often claims compliance with EN 50525, but this excludes braid.
Conclusion
CY cable is a screened, flexible multicore cable perfect for EMC‑sensitive environments. It surpasses YY where interference is present and offers better signal protection than SY in most automated systems. Always install with proper glands, earth the screen correctly, and comply with UK standards—including documenting its justified use. If you need further assistance or want to view our full range, visit Batt Cables today!
