Glossary
Cable Terminology
| Absence of Halogen |
| Halogen-free cables are made without halogens in the composition of their plastic materials. At SAB, materials such as SABIX®, Besilen®, Polyethylene, Polypropylene, and thermoplastic elastomer compounds (TPE) are used, ensuring that they do not contain hazardous stabilizers with heavy metals or plasticizers. |
| • Flame Protection & Safety: Any flame-retardant additives used in these materials are environmentally safe. |
| • Low Toxicity in Fire: Many halogen-free SABIX® (PO-based) compounds do not release corrosive or toxic gases in the event of a fire and minimize smoke emissions. They offer excellent flame resistance and help prevent fire propagation. |
| • Testing & Standards: The absence of halogens in cable materials is tested according to IEC 60754-1 (DIN EN 60754-1, VDE 0482-754-1). This test measures the hydrohalogenic acid content, which must be less than 0.5% for a material to be classified as halogen-free under the standard. |
| Adhesive (smooth, sticky, adhesive) Low Adhesion (sliding, rough, not sticky, non-adhesive) |
| Adhesive force refers to the attraction between particles of different materials and compounds. This force acts in various situations, such as paint adhering to a wall or chalk sticking to a board. The strength of adhesion varies depending on the materials involved. |
| For example, smooth and shiny plastic surfaces can attract dust particles from the air due to their adhesive properties. In the cable chain industry, it is crucial for outer sheaths to have a matte, low-adhesion surface to allow cables to glide smoothly within energy chains, reducing friction and wear. |
| Bending Radius and Minimum Bending Radius |
| The bending radius is the minimum radius a cable can be bent without causing damage or functional deterioration. A smaller bending radius requires greater cable flexibility or specific constructional adaptations. |
| Types of Minimum Bending Radius: |
| • Unique Bend – The cable is permanently installed and remains in a fixed position (e.g., switchboard wiring). |
| • Fixed Laying – The cable or conductor is permanently installed but can be reused in another location if removed. |
| • Flexible Application – The cable or conductor is used in flexible installations where it moves without forced mechanical guidance (e.g., connection cables for control panels). |
| • Permanent Flexible Application – The cable or conductor is exposed to continuous forced movement, such as in cable chains or when guided over deflection pulleys. |
| Important Guidelines: |
| • Avoid bending cables directly after a plug or crimped connection to prevent mechanical stress. |
| • Never bend cables beyond the recommended bending radius, as this can compress or stretch the individual conductor strands, leading to breakage. |
| • Do not route cables over sharp edges, as this can cause wire breakage and insulation damage, making the cable unsafe for humans and machines. |
| Calorific Value |
| The specific calorific value (Hi) represents the amount of energy released during the complete combustion of a material. It is typically expressed in megajoules per kilogram (MJ/kg) or kilowatt-hours per kilogram (kWh/kg). |
| Approximate values for calorific value: |
| • FEP, ETFE, PFA: approx. 1-2 kWh/kg |
| • SABIX® (PO-Basis): approx. 3-5 kWh/kg |
| • Besilen®: approx. 4-5 kWh/kg |
| • PVC: approx. 5-7 kWh/kg |
| • PUR: approx. 7-9 kWh/kg |
| • PE/PP: > 12 kWh/kg |
| Corrosiveness of Conflagration Gases |
| In the event of a fire, halogenated plastic materials release corrosive gases. For example, PVC emits hydrogen chloride gas, which, when combined with moisture, forms hydrochloric acid. This acid poses severe risks to the respiratory system and, as an electrically conductive substance, can cause short circuits, metal corrosion, and equipment failure. |
| The corrosiveness of fire-generated gases from plastic materials used in the cable industry is tested according to IEC 60754-2 (DIN EN 60754-2, VDE 0482-754-2). During this test, the material is burned and washed out to determine: |
| • pH value (acidity level) |
| • Conductivity (electrical impact of the residue) |
| For a material to meet the standard, it must have: |
| • pH > 4.3 |
| • Conductivity < 10 µS/mm |
| Halogen-containing materials do not meet these requirements. |
| EX Area |
| An EX area (or “area subject to explosion hazards”) is a special category in electrical applications where the presence of flammable substances in the air—such as gases, liquids, or dust—can create an explosive mixture. If an electric spark is generated by equipment, the consequences can be catastrophic. To prevent this, various safety measures are implemented. |
| Explosion Prevention Measures Most preventive measures focus on isolating potential spark sources from the environment using: |
| • Protective gases |
| • Pressurization |
| • Additional enclosures |
| Cable Requirements in EX Areas Unlike electrical equipment, cables have limited requirements in X areas: |
| • Durability: The cable construction must be robust to prevent damage easily. |
| • Compact & Round Shape: Cables must be compact and round to withstand sealing processes. |
| • Gas-Tight Protection: If an EX area is connected to a non-hazardous area, the cable must be gas-tight to prevent flammable materials from traveling through its interior. |
| Classification of EX Areas EX areas are classified based on: |
| • The type of hazardous material (gas, liquid, or dust). |
| • The frequency of exposure (always, regularly, or only in case of failure). |
| The required protection level for equipment is determined by these classifications, though its impact on cables is indirect. |
| FRNC, LSHF, LS0H/LSZH |
| In the cable industry, various terms are used to describe cables with improved burning characteristics, particularly in terms of smoke emission and halogen content: |
| • LS0H / LSZH (Low Smoke, Zero Halogen) – Low smoke density, halogen-free |
| • LSHF (Low Smoke, Halogen-Free) – Low smoke density, halogen-free |
| • FRNC (Flame Retardant, Non-Corrosive) – Flame retardant, halogen-free |
| We strongly recommend reviewing the complete data sheet, where the specific standard requirements met by the cable are clearly indicated. |
| Halogens |
| Elements such as fluorine, chlorine, bromine, iodine, and astatine belong to the halogen group and are found in the 7th main group of the periodic table. These elements are present in various chemical compounds and plastics, such as chlorine in Polyvinyl Chloride (PVC) and fluorine in Fluoroethylene Propylene (FEP). |
| Halogens are often added to plastic materials to enhance flame retardancy. However, in the event of a fire, they can release corrosive and toxic gases, leading to significant smoke emission. When halogenated gases come into contact with extinguishing water or humidity, they can form highly corrosive acids, posing serious health risks to humans and animals. Additionally, these corrosive byproducts can cause permanent damage to machine components due to corrosion. |
| Shielding |
| Shielding is a structural feature of a cable designed to prevent external electromagnetic interference (EMI) and reduce the emission of signals from the cable itself. Various shielding techniques offer different advantages and disadvantages: |
| Types of Shielding: |
| Foil Shields: |
| • Lightweight and cost-effective material with minimal impact on cable diameter. |
| • Lower conductivity compared to other shielding methods. |
| • Provides 100% coverage, making it highly effective at high frequencies (GHz) when properly manufactured. |
| • Prone to wear under mechanical stress. |
| Metal Wire Shields (Braided Shields): |
| • Consist of counter-rotating metal wires braided around the cable using specialized machines. |
| • Offer the highest conductivity among shielding types, making them ideal for environments with high levels of interference. |
| • Less effective at high frequencies (>100 MHz) due to gaps at wire intersections. |
| • Limited torsional flexibility due to the structure of the braid. |
| Wrapped Metal Wire Shields (Half Shielding): |
| • Uses copper wires wrapped in a single direction around the cable. |
| • Less coverage compared to braided shielding, but greater flexibility for torsional applications. |
| • More prone to gaps forming under high alternating bending stress compared to traditional braiding. |
| Filler Wires or Strands: |
| • A conductor in electrical contact with the shield along the cable core. |
| • Primarily used to facilitate easier connection to the shield, especially for foil shields, which are difficult to connect using standard methods. |
| • Helps when connecting wrapping or braiding to a plug’s pin contact. |
| Other Shielding Methods: |
| • Magnetic Foil Shields (µ-Metal Foils) – Highly effective against strong magnetic fields. |
| • Metallized Non-Woven Tapes – Help reduce foil wear but have low conductivity. |
| Custom Shielding Solutions: Most of these shielding techniques can be combined to enhance performance. Additionally, construction details and production processes can be adjusted to meet specific shielding requirements and mechanical stress conditions. |
| Smoke Density |
| When cables catch fire, the resulting smoke can obstruct visibility, making evacuation and rescue efforts more difficult. To assess this risk, smoke density is tested according to IEC 61034 (DIN EN 61034, VDE 0482-1034). |
| Testing Procedure: |
| • The test is conducted in a controlled room of defined size. |
| • Cables are suspended above a tray containing burning alcohol as the ignition source. |
| • A lamp and a photocell measure light transmission through the smoke. |
| • During the test, the reduction in light transmission must not exceed the specified limit, ensuring visibility remains at an acceptable level. |
| Voltage |
| An essential parameter in cable applications is the voltage rating, but depending on the intended use, different voltage ratings apply, and they are not always interchangeable. |
| Types of Voltage Ratings: |
| 1. Effective Voltage (RMS - Root Mean Square): For standard AC voltage applications, the effective voltage (Ueff) is commonly used. Since AC voltage alternates, the effective value represents the equivalent load of a constant DC voltage. The maximum peak voltage is nearly 50% higher than the RMS value. |
| 2. Peak Operating Voltage: |
| • Used for non-periodic applications, such as data cables (analog or digital). |
| • Applicable to cables that experience short-term high loads, where RMS values or regular peak voltages are not relevant. |
| • Instead, application-specific values may be used, such as ignition voltage (e.g., for gas discharge lamp cables). |
| • Test voltage used during production to evaluate a cable’s performance capabilities. |
| • These values represent short-term loads, and with the same insulation, they are generally higher than permanent load values, such as RMS voltage or peak voltage. |
| 3. Voltage Relative to Ground and Other Conductors: |
| • Voltage measurements can be referenced to ground (earth/mass) or to another conductor. |
| • Single conductor to ground (Uo): Only one insulation layer is active. |
| • Between two conductors (U): Two insulation layers provide protection, making U typically higher than Uo. |
Three-Phase AC Systems & Voltage Relationships
| In three-phase systems, the voltage shift of 120° between conductors results in an inter-phase voltage that is √3 times higher than the voltage between a conductor and ground. |
| According to VDE 0298-3, the highest permanently allowed operating voltage (Ub,max) under load reserve considerations follows these relationships: |
| Nominal Voltage (Uo/U) [V] |
AC Conductor/ Ground [V] |
AC Conductor/ Conductor [V] |
DC Conductor/ Ground [V] |
DC Conductor/ Conductor [V] |
| 230/400 | 254 | 440 | 330 | 660 |
| 300/500 | 318 | 550 | 413 | 825 |
| 50/750 | 476 | 825 | 619 | 1238 |
| 0.6/1 | 0.7 | 1.2 | 0.9 | 1.8 |
| 1.8/3 | 2.1 | 3.6 | 2.7 | 5.4 |
| These values illustrate the different voltage indications and their relationships in various systems. | ||||
| UL voltage values always refer to the highest effective system voltage. In DC and AC systems this is Uo, in three phase current systems U. | ||||
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