Views: 0 Author: Site Editor Publish Time: 2026-07-13 Origin: Site
In modern industrial automation, flexible signal cables serve as the critical nervous system connecting sensors, programmable logic controllers, actuators, and communication networks across manufacturing floors. The VDE European standard LiY series has established itself as the benchmark for flexible data and control cabling, engineered specifically for industrial automation, PLC control systems, sensor networks, bus communications, and instrumentation signal transmission. These cables must perform reliably under constant vibration, bending stress, electromagnetic interference, and varying environmental conditions while maintaining signal integrity across long transmission distances.
Selecting the correct cable model from the extensive LiY series is a decision that directly impacts system reliability, signal quality, and long term operational stability. With dozens of model variants differing in insulation material, shielding architecture, twisting configuration, and sheath composition, understanding the distinctions between each type is essential for engineers, procurement specialists, and system integrators. A mismatched cable can lead to signal degradation, electromagnetic compatibility failures, premature mechanical wear, and costly system downtime in critical industrial processes.
The LiY series encompasses a full range of VDE standard flexible signal cables, including unshielded PVC models for clean indoor environments, single layer copper braid shielded control cables for general industrial use, twisted pair signal cables for multi channel differential transmission, and dual layer high frequency bus cables with PE low capacitance insulation for the most demanding high speed communication applications, each engineered to meet specific electromagnetic compatibility, mechanical flexibility, and environmental resistance requirements across the full spectrum of industrial automation scenarios.
This comprehensive guide walks through every aspect of the LiY cable series, from the fundamental coding rules that define each model to detailed technical specifications, performance comparisons, and practical selection criteria. Whether you are designing a new automation system, upgrading existing cabling infrastructure, or sourcing components for a specific industrial application, this manual provides the technical depth needed to make informed, confident cable selection decisions.
Table of Contents
The LiY series employs a standardized letter coding system in which each character represents a specific structural or material attribute of the cable, including conductor type, insulation material, shielding method, twisting configuration, grounding arrangement, and sheath composition, enabling engineers to identify cable properties precisely and select the appropriate model for any given application without ambiguity.
The LiY series is a German VDE standard flexible data and control cable family. The letter coding is fixed and universally applicable across the entire product range, serving as the core basis for distinguishing cable structure and performance characteristics. Understanding these codes is the fundamental prerequisite for proper cable selection, as each letter combination directly corresponds to specific construction elements that determine the cable suitability for particular environments and signal types.
The coding system follows a logical sequence that mirrors the physical construction of the cable from conductor outward to the outer sheath. The first letters identify the conductor stranding class, followed by insulation material designation, then structural elements such as twisting and shielding, and finally the outer sheath material. This systematic approach allows users to decode any LiY variant and immediately understand its construction, performance capabilities, and intended application scope.
The following table provides a complete breakdown of each code letter and its corresponding meaning within the LiY series naming convention:
Code | Full Term | Meaning and Function |
|---|---|---|
Li | Flexible stranded conductor | Class 5 finely stranded soft copper conductor, high flexibility, designed for mobile and bending installation scenarios |
Y | PVC insulation | Polyvinyl chloride insulation or sheath, general purpose type, cost effective and widely applicable |
2Y | PE insulation | Polyethylene insulation, low capacitance and low signal attenuation, specifically designed for high frequency and high speed signal transmission |
C | Copper braid shield | Copper wire braid shielding, typically tinned copper, protects against external electromagnetic interference for EMC compliance |
TP | Twisted Pair | Core wires arranged in twisted pairs, significantly reduces crosstalk between adjacent wire pairs |
PIMF | Pair in Metal Foil | Individual pair aluminum foil shielding combined with overall copper braid, dual layer shielding for maximum interference protection |
JZ | With grounding core | Includes green yellow bicolor grounding protection core wire |
OZ | Without grounding core | Standard structure without grounding core wire |
PUR | Polyurethane sheath | Polyurethane outer sheath, oil resistant, wear resistant, and bend resistant, suitable for drag chain mobile applications |
LSZH / H | Low Smoke Zero Halogen | Flame retardant material with low smoke and zero halogen emissions, environmentally friendly and fire safe, suitable for public buildings and enclosed spaces |
By combining these codes, the LiY series generates dozens of model variants, each tailored to a specific combination of flexibility, shielding performance, signal integrity, and environmental resistance. For example, a cable designated as Li2YCY PIMF immediately tells the engineer that it features a Class 5 flexible conductor (Li), PE low capacitance insulation (2Y), copper braid overall shielding (C), and individual pair aluminum foil plus overall braid dual layer shielding (PIMF), making it the top tier choice for high frequency bus communication in strong interference environments.
The four core models of the LiY series are LiYY, LiYCY, LiYCY TP, and Li2YCY PiMF, each representing a progressively advanced level of shielding architecture, twisting configuration, and insulation technology designed for increasingly demanding industrial signal transmission requirements, from basic indoor control wiring to high speed bus communication in severe electromagnetic environments.
These four models serve as the foundational variants from which the entire LiY product line is derived. Each model addresses a distinct tier of application complexity, and understanding their structural differences, electrical parameters, and optimal use cases is essential for making accurate cable selection decisions. The following sections provide a detailed examination of each model.
Engineers should pay particular attention to the relationship between shielding structure and electromagnetic compatibility performance, as well as the impact of insulation material on signal capacitance and transmission distance. These factors, combined with the twisting configuration, determine the overall signal integrity and reliability of the cable in real world industrial installations.
The LiYY is a multi core flexible conductor PVC insulated PVC sheathed unshielded control cable. Its construction consists of Class 5 soft copper conductors, PVC insulation, core wires stranded according to structural requirements, and a PVC outer sheath, with no shielding structure of any kind. This model is rated for 300/500V operation and exhibits relatively high capacitance values with no electromagnetic interference protection capability.
The core characteristics of the LiYY include excellent flexibility, low cost, and lightweight installation convenience. The absence of any shielding layer makes this cable unsuitable for environments with electromagnetic interference, but its simplicity also means it is easy to strip, terminate, and route within confined spaces such as control cabinet interiors. The PVC insulation and sheath provide adequate mechanical protection and electrical insulation for standard indoor applications.
The LiYY is specifically designed for indoor dry environments free from electromagnetic interference. Typical applications include control cabinet internal wiring, ordinary switching value signal transmission, office equipment connectivity, small instrument internal wiring, and short distance signal connections within enclosures. This cable should only be deployed in clean electromagnetic environments where no significant interference sources are present, as it offers no protection against external electromagnetic fields or crosstalk between adjacent cables.
The LiYCY is a multi core flexible conductor PVC insulated copper braid overall shielded PVC sheathed control cable. Its construction comprises Class 5 soft copper conductors, PVC insulation, standard core stranding, tinned copper braid overall shielding, and a PVC outer sheath. Rated at 300/500V, this model provides basic electromagnetic compatibility protection through its overall copper braid shield, which effectively defends against external electromagnetic interference.
The core features of the LiYCY include overall shielding that resists external electromagnetic interference, though it lacks any twisted pair structure and therefore offers no protection against internal crosstalk between wire pairs. The tinned copper braid provides both electromagnetic shielding and a continuous ground path when properly terminated. This makes the LiYCY a significant upgrade over the LiYY for any application where electromagnetic interference may be present, even at moderate levels.
The LiYCY is suited for general industrial environments, machine tool equipment, PLC single point signal transmission, instrumentation control lines, and applications with mild electromagnetic interference. It is compatible with RS232 serial communication, ordinary switching value signals, and single channel analog signal transmission. The overall shield effectively contains the cable internal signals while preventing external interference from corrupting transmitted data, making it the standard choice for routine industrial control and monitoring applications.
The LiYCY TP is a PVC insulated twisted pair copper braid overall shielded data cable. Its construction consists of Class 5 soft copper conductors, PVC insulation, core wires arranged in twisted pairs, wrapping tape, tinned copper overall braid shielding, and a PVC sheath. The twisted pair structure eliminates crosstalk between wire pairs, while the overall shield defends against external interference, providing comprehensive internal and external protection simultaneously.
The core advantage of the LiYCY TP lies in its dual protection architecture. The twisted pair configuration ensures that electromagnetic fields induced in one conductor are equally induced in its paired conductor, allowing differential signal receivers to reject common mode noise effectively. This is particularly important for analog signal transmission where signal integrity is critical. The overall copper braid shield adds an additional layer of defense against external electromagnetic sources such as motor drives, power lines, and radio frequency emitters.
The LiYCY TP is the preferred choice for multi channel differential signals, 4 to 20 mA analog signal transmission, servo encoder feedback, multi channel sensor networks, and short distance RS485 communication in moderate industrial interference environments. Its balanced twisted pair construction makes it especially effective for applications where multiple signal pairs must coexist within the same cable without mutual interference, ensuring clean signal transmission across all channels.
The Li2YCY PiMF is a PE insulated single pair aluminum foil individual shield plus overall copper braid dual layer shielded high speed data cable. Its construction comprises Class 5 soft copper conductors, PE low capacitance insulation, individual pair twisting, per pair aluminum foil individual shielding with drain wire, overall copper braid total shielding, and a PVC outer sheath. This represents the most advanced shielding architecture in the core LiY series.
The core advantages of the Li2YCY PiMF include extremely low signal capacitance, ultra low transmission attenuation, and dual layer full shielding that completely eliminates both internal crosstalk and external electromagnetic interference. The PE insulation material has inherently lower dielectric constant compared to PVC, resulting in significantly reduced capacitance per unit length. This allows signals to travel farther and faster without degradation, making it ideal for high frequency and long distance applications.
The Li2YCY PiMF is designed for high precision measurement instruments, Profibus bus networks, high speed RS485 communication, high frequency sensors, and industrial sites with severe electromagnetic interference. It is the dedicated cable for high end automation bus signal transmission, where signal integrity over distance and immunity to intense interference are paramount. The individual pair shielding ensures complete isolation between signal pairs, while the overall braid provides robust defense against external noise, making this cable the ultimate choice for mission critical industrial communication systems.
The four core LiY cable models differ significantly across insulation material, shielding structure, twisting configuration, capacitance characteristics, and interference protection level, with Li2YCY PiMF offering the highest performance for high speed and high interference environments, LiYCY TP providing excellent balanced protection for multi channel analog signals, LiYCY delivering basic electromagnetic compatibility shielding for general industrial use, and LiYY serving as the most economical solution for clean, low interference indoor applications.
Understanding the performance differences between these four models is critical for matching cable specifications to application requirements. The comparison below highlights the key technical distinctions that influence signal quality, transmission distance, electromagnetic compatibility, and overall system reliability. Each model occupies a specific performance tier, and selecting the appropriate tier ensures optimal cost performance balance without compromising signal integrity.
The progression from LiYY to Li2YCY PiMF represents a systematic increase in electromagnetic protection, signal transmission quality, and environmental adaptability. Each step up the ladder adds specific structural elements that address particular signal integrity challenges, from basic external interference shielding to comprehensive dual layer protection with low capacitance insulation for high frequency bus communication.
The following table provides a side by side comparison of the four core models across all critical performance dimensions:
Cable Model | Insulation Material | Shielding Structure | Twisting Configuration | Capacitance | Interference Protection | Application Scenario |
|---|---|---|---|---|---|---|
LiYY | PVC | None | Standard stranding, no twist | High | None | Indoor unshielded general control wiring |
LiYCY | PVC | Single layer copper braid overall shield | Standard stranding, no twist | High | Moderate (external interference defense) | General industrial single signal, mild interference |
LiYCY TP | PVC | Single layer copper braid overall shield | Twisted pairs | Medium | Good (external defense plus crosstalk prevention) | Multi channel analog, differential communication, moderate interference |
Li2YCY PiMF | PE low capacitance | Per pair aluminum foil plus overall braid dual shield | Individual twisted pairs | Extremely low | Top tier (full dimension shielding) | High speed bus, high precision signals, severe interference sites |
From the comparison table, several key patterns emerge. First, the insulation material transitions from PVC to PE when moving to the high frequency model, directly reducing signal capacitance and attenuation. Second, the shielding architecture evolves from none to single layer to dual layer, progressively increasing electromagnetic protection. Third, the twisting configuration advances from standard stranding to twisted pairs to individually shielded twisted pairs, systematically reducing internal crosstalk. These three dimensions of improvement work in concert to deliver the signal integrity required by increasingly demanding industrial communication protocols.
The complete LiY series comprises five major product categories encompassing unshielded PVC series for general applications, PVC insulated overall shielded series for industrial shielding, PE low capacitance high frequency shielded series for bus and high speed signals, low smoke zero halogen flame retardant series for public buildings and enclosed spaces, and high temperature resistant special series, collectively covering all mainstream industrial automation cabling scenarios.
Beyond the four core models, the LiY series includes numerous specialized variants designed for specific industrial requirements. These variants incorporate additional structural modifications such as high density braiding for enhanced shielding, PUR sheathing for drag chain compatibility, high flexibility designs for dynamic applications, and specialized materials for extreme environments. The full model directory below provides a comprehensive reference for all available LiY variants.
Each category within the LiY series serves a distinct application segment, and many models can be cross referenced to identify equivalent or upgraded alternatives when specific models are unavailable or when application requirements change. Engineers should use this directory as a reference guide when specifying cables for new projects or when seeking alternatives for existing installations.
LIYY: Standard unshielded multi core flexible control cable
LIYY TP: Unshielded twisted pair cable, twisting only, no shielding
LIYY JZ: Unshielded control cable with grounding core
LIYY OZ: Standard unshielded cable without grounding core
LIYCY: Standard overall shielded multi core cable
LIYCY TP: Twisted pair overall shielded signal cable
LIYCY JZ: Shielded cable with grounding core
LIYCY OZ: Shielded cable without grounding core
LIYCY CY: High density braid reinforced shielded cable
LIYCY PUR: PUR wear resistant sheath drag chain dedicated shielded cable
LIYCY TR: High flexibility dynamic bending drag chain dedicated cable
Li2YCY: PE insulated single layer overall shielded cable
Li2YCY TP: PE insulated twisted pair overall shielded cable
LI2YCY PIMF: Dual layer full shielded high speed bus cable
LI2YCY PIMF JZ: Dual layer shielded bus cable with grounding core
LiHCH: Low smoke zero halogen unshielded cable, alternative to LIYY
LiHCHCY: Low smoke zero halogen overall shielded cable, alternative to LIYCY
Li2HCH PIMF: Low smoke zero halogen dual layer shielded high frequency cable
SiLiYCY: Silicone rubber insulated high temperature shielded cable, designed for high temperature operating conditions
This comprehensive model directory demonstrates the breadth of the LiY series and its ability to address virtually any industrial signal transmission requirement. From the simplest unshielded indoor wiring to the most sophisticated dual shielded high frequency bus cable, the LiY series provides a complete solution matrix for industrial automation, control, and communication applications.
The LiY series shares a common set of technical specifications across all model variants, including VDE 0295 Class 5 finely stranded conductors, rated voltages of 250V for smaller cross sections and 300/500V for larger ones, DIN 47100 standard color coding, operating temperatures ranging from minus 20 degrees Celsius to plus 80 degrees Celsius, and bending radius requirements of at least 6 times the cable outer diameter for fixed installation and 15 times for dynamic movement.
All models in the LiY series utilize VDE 0295 Class 5 multi strand soft bare copper or tinned copper conductors. This conductor class ensures the high flexibility that defines the LiY series, allowing the cables to withstand repeated bending and movement without conductor fatigue or breakage. The fine stranding also improves surface area contact at termination points, ensuring reliable electrical connections.
The rated voltage varies by conductor cross section. For cables with conductor sizes from 0.14 to 0.75 mm squared, the rated voltage is 250V. For cables with conductor sizes of 1.0 mm squared and above, the rated voltage increases to 300/500V. This voltage rating system ensures appropriate insulation thickness and dielectric strength for each conductor size category.
The complete set of general technical parameters is summarized below:
Conductor specification: VDE 0295 Class 5 multi strand soft bare copper or tinned copper
Rated voltage: 250V for 0.14 to 0.75 mm squared conductors, 300/500V for 1.0 mm squared and above
Color coding standard: Strictly follows DIN 47100 European industrial core wire color standard
Operating temperature: Fixed installation from minus 20 to plus 80 degrees Celsius, occasional mobile installation from minus 5 to plus 70 degrees Celsius
Bending radius: Fixed installation at least 6 times cable outer diameter, dynamic movement at least 15 times cable outer diameter
Certifications: CE and RoHS compliant, suitable for industrial automation import and export equipment integration
The DIN 47100 color coding standard ensures consistent wire identification across the entire LiY series, simplifying installation, maintenance, and troubleshooting. The strict adherence to this standard means that any technician familiar with European industrial cabling can immediately identify wire functions without additional documentation. The CE and RoHS compliance certifications ensure that LiY cables meet European Union safety and environmental standards, making them suitable for use in equipment destined for international markets.
Selecting the right LiY cable depends primarily on the application environment and signal type: use LiYY for clean indoor wiring without interference, LiYCY for general industrial single signal transmission with mild interference, LiYCY TP for multi channel differential and analog signals, Li2YCY PiMF for high speed bus communication and strong interference environments, LiYCY PUR or LiYCY TR for drag chain and frequent movement applications, and LiHCH series for fire safety and enclosed space requirements.
The selection process should begin with a thorough assessment of the application environment, including the presence and intensity of electromagnetic interference, the type of signals being transmitted, the required transmission distance, and any mechanical or environmental constraints such as bending, movement, temperature extremes, or fire safety regulations. Each of these factors directly influences which LiY model is most appropriate for the application.
The following selection guide provides a quick reference for matching common application scenarios with the recommended LiY cable model. Engineers should use this guide as a starting point and then verify the selection against the detailed technical specifications and general parameters provided in the earlier sections of this manual.
No interference indoor wiring, ordinary power and switching signals: Select LiYY
General industrial site, single channel analog or switching signals, mild interference: Select LiYCY
Multi channel differential signals, 4 to 20 mA analog, standard RS485 communication: Select LiYCY TP
High speed bus, high precision instruments, strong interference environments, long distance communication: Select Li2YCY PiMF
Drag chains, frequently moving equipment: Select LiYCY PUR or LiYCY TR
Building fire safety, poorly ventilated enclosed spaces: Select low smoke zero halogen LiHCH series
When in doubt, always select a cable with a higher interference protection level than the minimum required. The cost difference between cable tiers is typically marginal compared to the cost of signal failures, system downtime, and troubleshooting in industrial environments.
It is also important to consider future system upgrades when selecting cables. If there is any possibility that the application may evolve to require higher speed communication or operate in a more interference intensive environment, selecting a higher tier cable such as LiYCY TP or Li2YCY PiMF from the outset can eliminate the need for costly cable replacement in the future. This forward looking approach to cable selection is a hallmark of robust industrial system design.
The VDE European standard LiY series provides a comprehensive and systematically organized solution for industrial flexible signal cabling. From the economical and straightforward LiYY for clean indoor environments to the sophisticated Li2YCY PiMF with dual-layer shielding and PE low-capacitance insulation for high-speed bus communication in severe electromagnetic environments, the series covers every tier of industrial application requirements.
Successful cable selection depends on understanding the model coding system, evaluating the specific application environment and signal characteristics, and matching these requirements to the appropriate cable model. By following the coding rules, technical specifications, comparison data, and selection guide presented in this manual, engineers and procurement professionals can confidently specify the correct LiY cable for any industrial automation, control, or communication application, ensuring reliable signal transmission and long-term system performance.
To achieve maximum mechanical longevity and reliable system connectivity on the factory floor, partnering with an experienced manufacturing pioneer makes all the difference. As a premier global supplier of high-performance transmission products, RONA engineers a complete portfolio of VDE-compliant, type-tested signal and control systems optimized to eliminate industrial EMI and survive harsh mechanical drag-chain environments.
