Understanding electrical cable types list is essential for safe and efficient power distribution in residential, commercial, and industrial environments. This guide breaks down the most common cables by construction, voltage rating, and application so you can select the right option for each project.
Use the summary table below to compare key specifications at a glance and match cable properties to your electrical requirements.
| Cable Type | Typical Use | Voltage Rating | Key Feature |
|---|---|---|---|
| NM-B (Romex) | Residential dry locations | 600V | Plastic sheathing, easy to install |
| THHN/THWN | Commercial conduits | 600V to 2000V | Thermoplastic heat and moisture resistant |
| MC Cable | Industrial and commercial wiring | 600V to 2000V | Metal clad armor, added protection |
| UF-B Cable | Underground direct burial | 600V | Moisture resistant, no conduit needed |
| RHH/RHW-2 Cable | Wet locations and conduit | 600V to 2000V | Heat and moisture resistant |
Residential Romex and Non-Metallic Sheathed Cable
NM-B, commonly called Romex, is the backbone of modern household wiring. It consists of multiple insulated conductors wrapped in a single plastic jacket, making it quick to pull and terminate.
Key Specifications for NM-B
Voltage capacity, conductor material, and ampacity define safe use of NM-B cable. Typical ratings are suitable for general-purpose circuits, but local codes may impose additional limits.
Commercial Thermoplastic Heat Resistant Cable
THHN and THWN cables are designed for demanding environments where heat, moisture, and short circuits must be controlled. These wires feature a thermoplastic PVC jacket and nylon coatings that resist solvents and abrasion.
Conduit and Junction Box Applications
In commercial and industrial settings, THHN/THWN wires run through metal conduit or electrical trays, protecting conductors from physical damage and enabling future modifications without rewiring.
Metal Clad Cable for Industrial Wiring
MC cable combines insulated conductors with an interlocked metal armor, delivering high protection against damage, fire, and electromagnetic interference. This construction supports direct attachment to devices and enclosures using connectors.
Suitable Voltage and Grounding Options
MC cable is available in a range of voltage ratings from 600V to 2000V, with options for equipment grounding through the metal sheath, which simplifies compliance with safety standards.
Underground and Direct Burial Cable
UF-B cable is engineered for underground installations, with a solid plastic sheath that shields conductors from soil moisture, chemicals, and physical stress. It can be buried directly without conduit in most jurisdictions.
Installing UF-B in Residential Projects
When running power to detached garages, outdoor lighting, or subpanels, UF-B offers a reliable, low-maintenance solution that reduces the need for additional raceways.
Key Takeaways for Electrical Cable Selection
- Match cable voltage rating and insulation to environmental conditions and code requirements
- Use NM-B for standard indoor residential circuits and avoid wet or exposed areas
- Select THHN/THWN for commercial conduit runs with heat and moisture protection
- Specify MC cable where mechanical protection, grounding, and fire resistance are critical
- Plan underground feeds with UF-B for direct burial or THHN in conduit for service flexibility
FAQ
Reader questions
Can I use NM-B cable in an outdoor exposed location?
No, NM-B cable is intended for dry indoor use only. Exposure to moisture, sunlight, or physical damage can compromise insulation and create safety hazards.
What is the advantage of THHN over THWN in conduit installations?
THHN provides better heat resistance at higher operating temperatures, while THWN offers superior moisture resistance. Many installations specify THWN-2 for improved durability in wet locations.
Is MC cable suitable for both indoor and outdoor applications?
Yes, MC cable can be used indoors and outdoors when installed according to manufacturer specifications and local electrical codes, including proper support and sealing where needed.
How do I choose between UF-B and THHN in conduit for underground feeds?
Use UF-B for simple direct burial without conduit, and choose THHN in conduit when future access or pulling additional wires is expected. Evaluate soil conditions, load requirements, and local codes.