If you're planning an outdoor wiring project or need power to a detached building, you may have come across the term UF-B wire. But what exactly is UF-B wire, and what is it used for?
uf-b wire
In this article, we’ll break down the meaning, structure, and common applications of UF-B cable so you can make an informed choice for your next electrical installation.
📘 What Is UF-B Wire?
UF-B stands for Underground Feeder, Type B. It is a non-metallic sheathed electrical cable designed to carry power underground and in wet locations without requiring a conduit.
This type of wire features:
Solid copper conductors
Individual insulation for each conductor
A rugged PVC outer jacket
A bare copper ground wire
Unlike standard indoor cables such as NM-B (Non-Metallic), UF-B wire is specially designed to withstand moisture, corrosion, and direct burial in soil.
🔍 UF-B Wire Meaning and Construction
Let’s break down the components of a typical UF-B cable:
| Component | Description |
|---|---|
| “UF” | Underground Feeder – indicates it's rated for underground use |
| “B” | Type B – refers to the solid PVC outer jacket and heat rating |
| Conductors | Solid copper (sizes range from 14 AWG to 4 AWG) |
| Insulation | Thermoplastic PVC around each conductor |
| Jacket | Tough, sunlight- and moisture-resistant PVC |
| Ground wire | Bare copper for grounding and safety |
🛠️ What Is UF-B Wire Used For?
UF-B cable is commonly used in residential, light commercial, and agricultural settings. Its direct burial rating makes it a go-to choice for:
Outdoor lighting
Garden or farm equipment
Underground feeder lines to sheds, barns, garages
Septic systems, well pumps, and irrigation timers
Remote GFCI outlets and outdoor receptacles
It is ideal for wet, damp, or corrosive environments where standard indoor wire would fail.
⚡ UF-B Wire vs NM-B Wire: What's the Difference?
| Feature | UF-B Wire | NM-B Wire |
|---|---|---|
| Usage | Outdoor / underground | Indoor, dry areas only |
| Jacket Type | Thick, water-resistant PVC | Softer PVC jacket |
| Burial | Direct burial approved | Not suitable for burial |
| Moisture Resistance | High | Low |
✅ Benefits of UF-B Wire
Eliminates need for conduit in underground installations
Resists moisture, corrosion, and UV exposure
Complies with NEC Article 340 for underground wiring
Suitable for permanent outdoor wiring projects
Long-lasting and durable, even in harsh environments
🧠 Common UF-B Wire Sizes
| Size | Typical Use |
|---|---|
| 14/2 | Small outdoor lights, landscape circuits |
| 12/2 | Garden outlets, garage lights |
| 10/2 | Water heaters, pumps, A/C units |
| 6/3 | Subpanels for outbuildings |
| 4/3 | Heavy-load equipment, remote workshops |
📌 Conclusion
UF-B wire is an essential solution for outdoor and underground electrical wiring. Its durability, moisture resistance, and direct burial capability make it ideal for a wide range of permanent installations. Whether you're powering a backyard shed or installing a new lighting system in your garden, UF-B cable provides safe, code-compliant performance.
📞 Need Help Choosing the Right UF-B Cable?
At TOT Wire & Cable, we stock all common sizes of UF-B wire at competitive prices. Contact us for product specs, bulk pricing, or technical advice on your underground wiring project.
👉 Contact Us Now to get a quote or speak with a wire expert!
