Elevator modernization projects often face one common challenge: limited cabling inside the traveling cable. For applications such as elevator CCTV, intercom, multimedia screens, or IoT devices, many integrators look to repurpose existing 2-wire conductors within the elevator cable instead of installing new Ethernet lines.
In this article, we'll explain the main types of 2-wire cables found in elevator systems, compare their strengths and weaknesses, and discuss which ones are most suitable for Ethernet or PoE transmission via Ethernet Extenders.
A “2-wire” in elevator cables refers to any twisted or untwisted pair of copper wires (typically 0.75–1.5 mm² in cross-section) used for control signals, voice communication, or alarms. With proper conversion devices such as Ethernet over 2-wire extenders, these pairs can also transmit data and power.
| Type | Description | Pros | Cons | Best Use Case |
|---|---|---|---|---|
| Control Cable Pair | Usually used for floor call signals or door commands. Often solid or stranded copper | Widely available; stable; low resistance | May be shared; interference from control system | Ethernet transmission with good EMI isolation |
| Twisted Pair (Shielded/Unshielded) | 2 wires twisted together to reduce EMI; sometimes with foil shielding | Lower crosstalk and EMI; good signal quality | May be thin (0.5mm²); varies by manufacturer | Ideal for Ethernet extender solutions |
| Speaker Wire / Audio Cable | Typically stranded copper; used for elevator speakers or emergency intercoms | Flexible, easy to crimp; 1.0–1.5mm² | Not twisted; more prone to interference | Acceptable for low-frequency applications or short-distance Ethernet |
| Alarm Signal Wire | For fire alarms or over-speed sensors; sometimes 2-core PVC cable | Consistent quality; good insulation | Often shared with other systems | Only use if spare, unoccupied cores are available |
| Old Analog Phone Line | Used in legacy emergency intercoms; flat or twisted | Already runs from cabin to control room | May degrade over time; may be in use | Upgrade path to IP intercom |
If you're planning to use 2-wire for IP network transmission, keep in mind the following:
Wire Gauge: Thicker wires (1.0–1.5 mm²) have lower resistance, better for longer distance PoE.
Shielding: Shielded twisted pairs offer better protection in noisy elevator environments.
Length: Most Ethernet extenders support 100–1000 m depending on wire quality.
Isolation: Avoid using pairs that carry power or relay control signals to prevent interference.
Before reuse, test the continuity and insulation resistance of the 2-wire cable.
Use extenders that support PoE + Ethernet over 2-wire, with OFDM modulation for best performance.
In high-rise buildings, consider multi-pair utilization and point-to-point setup for maximum stability.
If wire type is unclear, refer to the elevator traveling cable documentation or consult the elevator manufacturer.
In many elevator network retrofit projects, leveraging the existing 2-wire within the traveling cable is a cost-effective and time-saving solution. Whether you're deploying CCTV, VoIP intercoms, multimedia screens, or IoT devices, understanding the type and quality of the available 2-wire cable is key to a stable, future-proof system.
Looking for a 2-wire Ethernet transmission solution?
Ourten's Ethernet-over-2-wire extenders support PoE transmission up to 1000m — optimized for real-world elevator installations.
