Low voltage cables are designed to carry electrical signals or power below 50 volts, commonly used in applications like security systems, landscape lighting, audio/video setups, thermostat connections, and data transmission. Choosing the right type of low voltage cable is essential for safety, performance, and code compliance.
low voltage cable types
In this guide, we cover:
What low voltage cables are
The most common low voltage cable types
Their applications and specs
How to choose the right cable for your project
⚡ What Is a Low Voltage Cable?
A low voltage cable carries electricity or data at a voltage level below 50V AC or 120V DC. They are generally used in:
Class 2 and Class 3 power-limited circuits (per NEC Article 725)
Control systems
Communication wiring
Low-power lighting systems
Structured cabling for smart homes
These cables differ by gauge (AWG), conductor type (solid/stranded), insulation, shielding, and number of conductors.
📦 Common Low Voltage Cable Types
Below are the most widely used low voltage cable types with descriptions, specs, and where you’ll typically see them used:
1. Thermostat Wire (18/2, 18/5)
Voltage Rating: 24V
Conductor: Solid copper
Use Case: HVAC thermostat control, doorbells
Notes: Color-coded; 2–8 conductors
2. Speaker Wire (16/2, 14/2, 12/2)
Voltage Rating: 12V–24V audio signal
Conductor: Stranded copper (high strand count)
Use Case: Home theater, in-wall or outdoor speakers
Notes: Marked for polarity (+/-)
3. Landscape Lighting Cable
Gauge: 12 AWG, 14 AWG
Voltage: 12V AC/DC
Insulation: UV-resistant, direct burial rated
Use Case: Outdoor lighting, garden or path lights
Notes: Flat, two-conductor configuration
4. Alarm/Security Wire (22/2, 22/4)
Voltage Rating: 12V–24V
Conductor: Stranded copper
Shielding: Often shielded for EMI protection
Use Case: Motion sensors, window/door contacts, alarm panels
Notes: Low capacitance improves signal integrity
5. Communication Cable (Cat5e, Cat6, Cat6a)
Type: Twisted-pair Ethernet cable
Voltage: PoE < 48V DC
Use Case: Internet, VoIP, IP cameras, smart devices
Shielding: UTP (unshielded), STP (shielded) available
Notes: Rated by bandwidth (MHz) and data speed
6. Coaxial Cable (RG6, RG59)
Voltage Rating: <50V DC
Use Case: CCTV, satellite, cable TV
Shielding: Heavy shielding and dielectric insulation
Impedance: 75 ohms typical
Notes: RG6 used for HDTV and long-distance signals
7. Control Cable / Multi-Conductor Cable
Voltage: 300V or less
Use Case: Building automation, relay control, intercoms
Conductors: 2–20+ stranded conductors
Shielding: Often shielded with foil or braid
Insulation: PVC, XLPE, or plenum-rated available
8. Low Voltage Lighting Cable (In-Wall or Track Lighting)
Gauge: 16–12 AWG
Voltage: 12V–24V
Use Case: LED strip lighting, track lighting
Compliance: UL Listed, CL2, CL3 rated for in-wall use
9. Fire Alarm Cable (FPL, FPLR, FPLP)
Voltage: 24V–48V
Certifications: UL Listed for fire alarm systems
Use Case: Smoke detectors, annunciators, alarms
Rating: Plenum (FPLP), riser (FPLR), or general purpose (FPL)
📊 Comparison Table of Low Voltage Cable Types
| Cable Type | Typical Voltage | Common Gauge | Shielding | Key Use |
|---|---|---|---|---|
| Thermostat Wire | 24V | 18 AWG | No | HVAC, doorbells |
| Speaker Wire | 12–24V | 16–12 AWG | No | Home audio |
| Alarm Wire | 12–24V | 22 AWG | Yes/No | Security systems |
| Ethernet (Cat5e/Cat6) | 48V PoE | 24 AWG | Optional | Networking, cameras |
| Landscape Cable | 12V | 12–14 AWG | No | Outdoor lighting |
| Fire Alarm Cable | 24V | 18–16 AWG | Often Yes | Smoke detectors, alarms |
| Coaxial Cable (RG6) | <50V | N/A | Yes | Video, CCTV |
🧰 How to Choose the Right Low Voltage Cable
Ask yourself these questions:
What’s the application?
Is it control, signal, or power?
Indoor or Outdoor?
Choose UV-rated or direct burial cable for outdoors.
Need shielding?
Use shielded cable in environments with electromagnetic interference (EMI).
What distance are you running?
For long distances, use larger gauge (12 AWG) to minimize voltage drop.
Plenum or riser?
Use plenum-rated cable (CMP) in ducts or air returns.
🛡️ Shielded vs Unshielded Low Voltage Cables
| Feature | Shielded Cable | Unshielded Cable |
|---|---|---|
| Interference | Resists EMI | More prone to interference |
| Flexibility | Slightly less flexible | More flexible |
| Cost | Higher | Lower |
| Use Case | Audio, security, data | Thermostats, lighting |
🧾 Relevant Standards & Codes
UL Listed, NEC Article 725, Class 2/3 Circuits
CL2 / CL3: In-wall installation
FPL, FPLR, FPLP: Fire alarm cables
CMP/CMR: Plenum/riser ratings
RoHS, CE: International environmental compliance
❓ FAQs
Q: Can I use speaker wire for LED lighting?
A: In short distances, yes—but make sure the gauge supports the current draw and the insulation is rated for in-wall use.
Q: What’s the difference between CL2 and CL3 cable?
A: CL3 has a higher voltage rating (300V) than CL2 (150V) and is suitable for more demanding installations.
Q: Is stranded or solid better for low voltage?
A: Stranded is more flexible (good for audio and movable components); solid is better for fixed runs like thermostats.
Q: Are Ethernet cables considered low voltage?
A: Yes, especially when used for PoE (Power over Ethernet) systems, which typically deliver 48V or less.
✅ Conclusion: The Right Cable Makes All the Difference
Choosing the correct low voltage cable type ensures optimal performance, safety, and longevity for your system—whether it’s a home theater, security system, landscape lighting, or smart home setup.
🧵 Need Help Finding the Right Low Voltage Cable?
TOT Wire & Cable supplies a full range of UL-certified, cost-effective low voltage cables for:
Security and alarm systems
Home audio and smart lighting
HVAC and building automation
Landscape and LED lighting
📞 Contact us now for expert support or bulk pricing.
