FAQ - Frequently Asked Questions

  1. How to choose the cable materials?

    1)
    Sheath: polyolefin SHF1; insulation: XLPE (polyethylene with cross-links);
    IEC 60092 standard; defined also LSZH or LS0H (Low Smoke Zero Halogen).
    Suitable for application in closed environments with many people: such as airplanes, trains, ships, road tunnels, etc.
    Average price.
    Resistance to temperature: - 25°C / +80°C.
    Resistance to water: very good.
    Resistance to oils: good.
    Resistance to abrasion: good. Flexibility: poor. Elasticity: poor.
    Resistance to flame: good (IEC 60332-1).
    It is halogen free, therefore when burning it does not emit corrosive gases, low smoke emission IEC 61034, low toxicity and acidity index IEC 60754.
    2)
    Sheath: non-cross-linked polyolefin; insulation: non-cross-linked polyolefin;
    defined also LSZH or LS0H (Low Smoke Zero Halogen).

    Suitable for application in closed environments with many people: such as airplanes, trains, ships, road tunnels, etc.
    Average price.
    Resistance to temperature: - 15°C / +70°C.
    Resistance to water: very good.
    Resistance to oils: moderate.
    Resistance to abrasion: sufficient. Flexibility: good. Elasticity: sufficient.
    Resistance to flame: very good (IEC 60332-3C).
    It is halogen free, therefore when burning it does not emit corrosive gases, low smoke emission IEC 61034, low toxicity and acidity index IEC 60754.
    3)
    Sheath: halogen-free irradiated PUR (polyurethane); insulation: halogen-free PP (polypropylene).
    Used in industrial automation for welding splatter resistant connections. The cross-linking by irradiation hardens the sheath outer layer, improving mechanical characteristics and high temperature resistance.
    Average-high price.
    Resistance to temperature: - 40°C / +105°C, also with dynamic applications.
    Resistance to water: good.
    Resistance to oils: very good. It stands also the test with many different chemical agents and hydrocarbons.
    Resistance to abrasion: very good. Flexibility: very good. Elasticity: very good.
    It is halogen free, therefore when burning it does not emit corrosive gases that could damage electronic circuits and machinery, but it does not comply with low opaque smoke emission standards required for closed environments.
    4)
    Sheath: halogen-free self-extinguishing PUR (polyurethane); insulation: halogen-free PP (polypropylene);
    known also as Li9Y11Y according to an old VDE standard.
    Frequently used for high quality connections in industrial automation.
    Average-high price.
    Resistance to temperature: - 40°C / +80°C, also with dynamic applications.
    Resistance to water: good.
    Resistance to oils: very good. It stands also the test with many different chemical agents and hydrocarbons.
    Resistance to abrasion: very good. Flexibility: very good. Elasticity: very good.
    Resistance to flame: sufficient.
    It is halogen free, therefore when burning it does not emit corrosive gases that could damage electronic circuits and machinery, but it does not comply with low opaque smoke emission standards required for closed environments.
    5)
    Sheath: Polyurethane Compound.
    Used for connections in industrial automation.
    Average price.
    Characteristics depend on the used PUR and PVC percentages and qualities.
    Resistance to water: generally poor.
    Resistance to flame: better than many PUR sheath, thanks to PVC presence.
    It contains halogen, therefore when burning emits opaque smoke and corrosive gases that can damage electronic circuits and machinery or be toxic for people inside closed environments.
    6)
    Sheath: PUR (polyurethane); insulation: PVC (polyvinyl chloride);
    known also as LiY11Y or LiYY11Y according to an old VDE standard.
    Frequently used for connections in industrial automation.
    Average price.
    Resistance to temperature: min. -15°C or lower, depending on PVC type, max 80°C.
    PVC can resist very well low temperature, but it becomes much more stiff. PUR has no problems down to - 40°C.
    Resistance to water: good.
    Resistance to oils: very good. It stands also the test with many chemical agents and hydrocarbons.
    Resistance to abrasion: average or very good, depending on the PUR sheath thickness.
    Flexibility: very good. Elasticity: sufficient.
    Resistance to flame: PVC is self-extinguishing, it extinguishes quickly after the flame is removed.
    It contains halogen, therefore when burning emits opaque smoke and corrosive gases that can damage electronic circuits and machinery or be toxic for people inside closed environments.
    External PUR sheath does not stand flame resistance tests.
    7)
    Sheath: PVC; insulation: PVC (polyvinyl chloride);
    known also as LiYY according to an old VDE standard.
    Very used for connections in industrial automation, electrical equipments for buildings, plants, etc.
    Convenient price.
    Resistance to temperature: min. -15°C or lower, max 70°C or higher, depending on the type.
    PVC can resist very well low temperature, but it becomes much more stiff.
    Resistance to water: good.
    Resistance to common oils: average.
    Resistance to abrasion: limited. Flexibility: very good. Elasticity: sufficient.
    Resistance to flame: self-extinguishing, it extinguishes quickly after the flame is removed.
    It contains halogen, therefore when burning emits opaque smoke and corrosive gases that can damage electronic circuits and machinery or be toxic for people inside closed environments.
    8)
    Sheath: EM2 rubber; insulation: EI4 rubber; H05RN-F according to standard HD 22.4, EN 50525-2-21.
    Suitable for wet and dry environments, permanent indoor and outdoor use.
    Average price.
    Resistance to temperature: - 30°C / +60°C, also with dynamic applications.
    Resistance to water: good.
    Resistance to oils: good.
    Resistance to abrasion: good. Flexibility: very good. Elasticity: good.
    Resistance to flame: sufficient.
    It is halogen free, therefore when burning it does not emit corrosive gases that could damage electronic circuits and machinery, but it does not comply with low opaque smoke emission standards required for closed environments.
    9)
    Sheath: PUR (polyurethane); insulation: EI6 rubber; H05BQ-F and H07BQ-F according to standard HD 22.10, EN 50525-2-21, CEI 19-10/10.
    Suitable for wet and dry environments, permanent indoor and outdoor use even at very low temperature.
    Average price.
    Resistance to temperature: - 40°C / +80°C, also with dynamic applications.
    Resistance to water: good.
    Resistance to oils: very good. It stands also the test with many different chemical agents and hydrocarbons.
    Resistance to abrasion: very good. Flexibility: very good. Elasticity: very good.
    Resistance to flame: sufficient.
    It is halogen free, therefore when burning it does not emit corrosive gases that could damage electronic circuits and machinery, but it does not comply with low opaque smoke emission standards required for closed environments.
    10)
    Sheath: Silicon; insulation: Silicon.
    Used for static applications with very low or very high temperature.
    Average-high price.
    Resistance to temperature: - 60°C / +180°C.
    Resistance to water: good.
    Resistance to oils: moderate.
    Resistance to abrasion: poor. Cut resistance: poor. Flexibility: very good. Elasticity: poor.
    Resistance to flame: good.
    It is halogen free, therefore when burning it does not emit corrosive gases that could damage electronic circuits and machinery.
    11)
    Sheath: FEP; insulation: FEP (Fluorinated Ethylene Propylene, teflon);
    known also as Li6Y6Y according to an old VDE standard.

    Employed in the industry in critical wiring because it maintains its characteristics practically unchanged, even with almost all chemical substances, in a temperature range between -80°C and +200°C.
    High price.
    Resistance to temperature:  -100°C / + 205°C.
    Resistance to water: very good.
    Resistance to oils: very good.
    Resistance to abrasion: very good. Flexibility: good. Elasticity: sufficient.
    Resistance to flame: non flame propagating.
    It contains halogen, therefore when burning emits opaque smoke and corrosive gases that can damage electronic circuits and machinery or be toxic for people inside closed environments.

  2. Is there any international unification for the colour name abbreviation in the electric cables ?

    Yes, the norm IEC 60757 establishes a unique worldwide abbreviation for wire colours.
    See http://www.shield.net/?download/support, into the section “Norms for cables: conductor section, class and colours” for the table of Colours Abbreviation.

  3. For an electric conductor, how can be transformed AWG to mm²?

    AWG means American Wire Gauge and it is the American system to classify the electrical conductors dimension.
    See http://www.shield.net/?download/support , in the section “Norms for cables: conductor section, class and colours” for the table of Conversion from AWG to mm².

  4. What is the electrical conductor class ?

    The IEC 60228 norm classifies the conductors according to the diameter of the small filaments which they are composed of.
    See http://www.shield.net/?download/support , into the section “Norms for cables: conductor section, class and colours” for the table of Conductor Section-Class.

  5. How is the maximum current carrying capacity calculated in low power electrical cable conductors?

    There are two factors to be considered for practical calculation of cable current carrying capacity:
    - copper resistance and current increase the cable temperature and if it becomes too high it can damage the insulation.
    - copper resistance and current also generate a voltage drop on the cable and if it is too high can interfere with correct plant operation.
    See http://www.shield.net/?download/support , in the section “Maximum voltage rating and current-carrying capacity calculation” for a detailed explanation and a few tables, which facilitate the practical calculation.
    Table data are based also on IEC 60204-1 – Machinery Safety.

  6. What do shielded cable and armoured cable mean?

    A cable is shielded when it has a metal layer between conductors and external sheath. The metal layer can be made in different ways:
    - aluminium foil
    - braid of bare or fine tinned copper wires
    - spiralled copper wire
    - braided copper screen + aluminium foil
    A cable is armoured if it has a copper or steel braid outside the cable sheath.
    See http://www.shield.net/?download/support , in the section "Cable signal transmission noises and shielding" for more details about the use of shielded and armoured cables.

  7. What are the best cables for a dynamic laying application?

    For employment in dynamic applications it is preferred to use polyurethane cables and class 6 copper wires.
    Also of importance is the way the cable is laid down.
    See www.shield.net/?download/support, in the section “Mobile laying cables” for several useful hints.