Single conductors

What are single conductors?

Single conductor refers to just one conductor, i.e. a plastic-insulated conductor without an outer jacket. Single conductors are considered important components for wiring electronic assemblies in machines, devices and control cabinets. Single conductors are also known as conductor lines, installation wires, bell wires, hookup wires, control wires or wiring lines.

Incidentally: one-conductor cables, one-conductor lines, single-conductor lines or single-conductor cables are all shielded and therefore do not count as single conductors.

In this guide, you will learn how the LAPP single cores differ, where they are used and which key questions are frequently asked.

You can find special cold-resistant and heat-resistant single conductors for expanded ambient temperatures (-195°C to +700°C) under “Temperature-resistant cables.”

Why don't single conductors actually need a jacket?

The outer jacket of a cable or line is a closed wrapping which protects the components underneath from being damaged or from any other external influences. Damage can be caused by excessive mechanical loads such as abrasion, shock, pressure or bending, or by significant chemical influences such as acids, alkalis, or oils. Thermal influences such as cold and heat, as well as physical influences such as UV radiation, also mustn't be allowed to have a negative effect on the electrical conductivity of cables.

Single conductors that are fixed in protected environments and are no longer moved afterwards are not normally exposed to these influences. As a result, they can also cope without a space-consuming outer jacket.

Where are single conductors used?

Single conductors are typically used for electrical installations in buildings and industrial plants. They are used as supply and discharge lines for control cabinets, to wire circuits inside machines and to connect lights and signaling systems.

If compliance with fire protection requirements is a key focus during cabling, halogen-free materials should be chosen that emit as few toxic fumes as possible in the event of a fire. If the cabling is carried out outside of Europe, attention must be paid to the corresponding product certification for the application area (e.g. UL, CSA).

Most single conductors must not be used outside of a closed system such as a control cabinet or cable duct without additional protection (e.g. an empty pipe or protective cable conduit). They are also suitable for fixed installation on or under plaster. Green-yellow single conductors may be installed directly on cable trays, in channels and troughs, but only as a potential equalization lines with a protective conductor function.

Looking for single conductor cables that can be moved in a highly flexible manner?

What are the differences between single conductors?

The LAPP single cores are distinguished by

• different core insulation materials,
• the permissible temperature range,
• certifications for different regions,
• their permissible nominal voltage and
• their packaging type.

A few single conductors are also shielded (LiYCY and Li2YCY).

Conductor insulation

Temperature ranges

The specified temperature range always applies in the case of fixed installation of the single conductors. The permissible temperature range may vary depending on the certification.

Temperature ranges using the example of the MULTI-STANDARD SC 2.1:

• HAR/IEC: -40°C to +70°C
• UL (AWM): to +105°C
• UL (MTW): to +90°C
• CSA (TEW): to +105°C

Certifications

The HAR marking on cables and lines is of particular importance for goods transport between European countries. This is because wherever national standards are not sufficient, harmonized markings are used throughout Europe. The aim of this is to distribute standardized products based on standardized designs, assemblies and test criteria. The testing mark stands for tested safety and quality and confirms that the single core is not only based on the type standard specified in the harmonisation document (HD), but also technically corresponds 100% to the type standard and is type-certified accordingly.

To use single conductors in North America, you must look out for UL or CSA certification. Depending on the area of application, the single conductor should include a UL Recognition Mark or a UL Listing Mark, for example. 

Nominal voltage

In Europe, control cabinet single conductors are designed for the voltage classes 300/500 V or 450/750 V. Depending on the single conductor certification, the nominal voltage permitted for North America may deviate greatly from this, as different voltage classes may be required for this area of application and depend on the corresponding standard. 

Information on the nominal voltage using the example of MULTI-STANDARD SC 2.1:

• HAR / IEC: U0/U: 450/750 V
• UL (AWM): U: 600 V
• UL (MTW): U: 600 V
• CSA (TEW): U: 600 V

In the case of harmonized types with HAR markings, the permissible nominal voltage is easily legible:

Packaging type

The LAPP single cores are available as a ring (100 m or in excess lengths for our TRONIC modules), on coils (100 m, 150 m, 250 m) or, only up to a max. 6 mm² however, also in large cardboard boxes (type K up to 3000 m, type E up to 9000 m).

Type abbreviations

The essential properties of a single conductor can be found via the type abbreviation. We will provide you with a short decryption aid using the example of H05V-K 1X0.5 YE:

• H = Basic type (harmonized type)
• 05 = Nominal voltage (300/500 V)
• V = Insulating material (PVC)
• K = cable type (fine-wire for fixed laying)
• 1 = Number of conductors (1)
• 0.5 = conductor cross-section (0.5 mm²)
• YE = Conductor insulation color (yellow)
   

Conductor insulation colors

The common conductor insulation colors for single conductors are gray, white, yellow, orange, red, violet, blue, green, brown, black, green-yellow, dark blue. Some single conductors are marked with a two-color spiral that allows the cable to be identified quickly in a small space.

Conductor cross-section

Control cabinet single conductors are typically made from a fine-wire, tin-plated copper strand (according to VDE 0295 class 5). It is flexible and therefore easy to install. Harmonised single cores are available in conductor cross-sections from 0.5 mm² to 240 mm²; the LiY single cores are available from 0.14 mm².

Screening