Low-Current Cables are mostly used below 1kV in building applications.

They are employed in systems such as audio, video, telephone, alarm, data, CCTV, and security within buildings. In cable classification, low-current cables fall under the category of low-voltage cables.

Selection Criteria for Low-Current Cables

With the advancement of technology, the cables used for all devices and their selection criteria have become highly important, both for human health and for flawless transmission. Therefore, special attention must be paid to the selection criteria of low-current cables.

When selecting a cable, the following basic criteria must be considered:

1. Standards Depending on the type of circuit and the area of use, cables must comply with certain local or international standards. Likewise, compliance with specific specifications may be required. The most important stage in cable selection is determining conformity with the specified standards or specifications.
2. Selection to Application Features

Cables must possess certain physical properties depending on the area of use. These physical properties can be adjusted by cable design. When selecting a cable, it is necessary to know where it will be used and what physical features it must have. For example:

• Flexibility
  • Fixed connection cables (no movement expected after installation)
  • Occasional movement (cables for hand tools or mobile devices)
  • Continuous movement (cables designed for constant motion during operation, with designs varying by type of movement)
• Bending
  • Single direction bending (cables in moving channels)
  • Bending and twisting (cables that twist while moving, e.g., cables coiled/uncoiled in baskets, cables in wind turbines twisting with rotor orientation, or robot connection cables)
  • Flat cables suitable for elevator (lift) connections
  • Reinforced cables for conveyors or cranes (e.g., drum-wound cables or cables with tension-bearing elements like aramid fibers or steel wires)
  • Crane cables collected in baskets (must withstand twisting motion as well)

3. Selection Criteria According to Environmental Conditions

It must be specified for what purpose and in which external environment the cable will be used: underground, above ground, weather conditions, aerial suspension, building surface mounting, or environments with chemical exposure. For indoor cables, special conditions must be noted: use in communal living areas, presence of electromagnetic fields, etc. Examples:

• Cables in protective hoses or shafts
• Semi-protected cables in trays
• Directly buried cables
• Cables for unusual environments
• Extreme hot or cold conditions
• Exposure to moisture, dust, oils, or chemicals
• UV (sunlight) and other outdoor conditions
• Impact-prone environments (need for armor)
• Friction (special sheath materials like PUR, PTFE)
• Resistance to rodents, termites, bacteria, and residues
• Resistance to wastewater or seawater
• Suitability for drinking water (preventing bacteria formation, non-toxic)
• Suitability for medical devices
• Other potential threats depending on cable or environment

4. Fire Performance Options

• Halogen-free
• Low smoke density
• Flame-retardant
• Fire resistance (according to specified standards)
• Fire performance class and calorific values (EN ISO 1716, EN 50265-2-1, FPEC 20 scenarios)

5. Selection Criteria According to Application Voltage

Cables are classified by applied voltage: low, medium, high, and very high voltage.

• Low-voltage cables (most diverse group):
  • Power transmission (typically 1–5 cores, shielded or unshielded)
  • Control (multi-core, shielded or unshielded)
  • Signal transmission (twisted pairs, triplets, or quadruples)
  • RF signal transmission (coaxial cables)
  • Fiber optic signal transmission

6. Selection Criteria According to EMI Properties

Electromagnetic interference (EMI) is the field affecting cables. To reduce exposure, one or more general and/or individual shields may be required.

• Shield type: braid
• Shield type: static
• Shield type: braid + static

7. Selection Criteria for Protective Armor

• Helical wound steel wires
• Braided type
• Tape type
• Composite and other armor types

8. Selection Criteria According to Conductor Structure

• Conductor cross-section (determined by current, voltage drop, short-circuit current, and fault tolerance)
• Number of conductors (based on number of connections)
• Ground conductor required? (single or split options available)
• Composite conductors (different cross-sections), e.g., cables transmitting both power and signal with different conductor designs

Usage Considerations

Low-current cables must possess certain features depending on their application areas. In places with high human density or valuable assets—such as smart or semi-smart buildings, hospitals, cinemas, theaters, schools, shopping centers, airports, factories, tunnels, etc.—features like non-flame propagation, low smoke density, and absence of toxic or corrosive gases are critical.

Additionally, if risks such as stress, impact, or rodents exist, the correct sheath or armor must be chosen. Depending on exposure to oil, chemicals, or moisture, cables may need protective properties. If other signals in the environment could interfere with transmission, shielding may be required. The type of shielding should be determined by experts based on signal characteristics and environment. For shielding quality, attention must be paid to braid coverage ratios.