1. What is UF-B Wire?
UF-B wire (Underground Feeder-B) is a type of electrical cable specifically designed for underground and outdoor power distribution. Its structure typically includes:
Solid copper conductors for stable current transmission
Thermoplastic insulation to prevent electrical faults
A solid, water-resistant sheath that protects the wire in wet or buried environments
Unlike indoor NM-B cables, UF-B wire is built for rugged conditions, offering both moisture resistance and UV protection, making it suitable for direct burial without conduit.
2. Common Uses of UF-B Wire
2.1 Underground Power Supply Applications
The most common use of UF-B wire is for underground power runs, such as:
Connecting a house to a detached garage, shed, or workshop
Supplying power to outdoor receptacles or lighting
Installing direct-burial cables between buildings
Popular sizes include:
uf wire 12 2 – Ideal for outdoor lighting or light-duty outlets
10 3 uf wire – Suitable for moderate-load appliances like air conditioners
8 3 uf wire – Best for heavy-duty equipment or subpanels
2.2 Outdoor Lighting and Landscape Wiring
UF-B wire is commonly used for powering garden lights, driveway lighting, and fence illumination. It eliminates exposed wiring and enhances safety.
Recommended: uf wire 12 2 is typically sufficient for most outdoor LED lighting systems.
2.3 Agricultural and Rural Applications
In rural areas, UF-B wire is ideal for extending power to remote areas on a property, such as:
Irrigation systems
Electric fences or farm equipment
Barns and greenhouses
For these applications:
10 3 uf wire works well for mid-range equipment
8 3 uf wire is recommended for high-power systems like large water pumps
3. Key Features and Advantages of UF-B Wire
UF-B wire offers several important benefits for outdoor and underground environments. First, it features a solid, water-resistant sheath, allowing for direct burial without conduit, which saves on labor and materials. It's also UV-resistant, making it suitable for outdoor exposure without degrading in sunlight. The solid copper conductors ensure consistent power delivery, even over long distances.
Additionally, UF-B wire comes in multiple gauges to suit different loads:
uf wire 12 2 is ideal for lighting and small tools
10 3 uf wire handles mid-level appliances
8 3 uf wire supports heavy-duty equipment and larger installations
Thanks to its durability, versatility, and ease of use, UF-B wire is one of the best choices for external electrical projects.
4. Installation Considerations for UF-B Wire
Proper installation of UF-B wire must comply with NEC (National Electrical Code) standards. It should be buried at least 18 inches deep, depending on soil type and location, to avoid physical damage and ensure safety. In areas where the wire may be exposed to mechanical impact, conduit is recommended even if it's not required.
Choosing the right wire gauge is essential:
uf wire 12 2 supports up to 20 amps
10 3 uf wire is good for 30-amp circuits
8 3 uf wire suits up to 40–50 amps
Also consider voltage drop over long distances. UF-B wire is not recommended for high-temperature areas or indoor exposed runs due to its rigid sheath. Always hire a licensed electrician to ensure safe, code-compliant installation.
5. How to Choose the Right UF-B Wire
When selecting UF-B wire, consider your power requirements, distance, and installation environment. Here's a quick guide:
| Model | Conductor Size | Typical Use | Ampacity |
|---|---|---|---|
| uf wire 12 2 | 2 conductors + ground, 12 AWG | Outdoor lighting, small outlets | 15–20A |
| 10 3 uf wire | 3 conductors + ground, 10 AWG | A/C units, water heaters, pumps | 30A |
| 8 3 uf wire | 3 conductors + ground, 8 AWG | Subpanels, high-power equipment | 40–50A |
Buying tips:
Always check for UL certification
Buy from trusted suppliers or hardware retailers
Avoid unbranded, uncertified wire
As a professional manufacturer of UF-B cables with UL certification, Dongguan Greater Wire & Cable Co., Ltd.has long served the electrical system construction in the United States and Canada. The cables are widely used in residential, farm, pump station and outdoor lighting projects. Our UF-B cables fully comply with UL 83 and UL 493 standards, with detailed printed traceability information, and are a compliant option recognized by electricians, contractors, and distributors in North America, Latin America, and South America.