Southwire 10/2 Solid Copper UF-B Underground Feeder Cable with Ground 250-Foot Roll – Model 13056755

The Southwire 10/2 UF-B is the residential underground feeder cable engineered specifically for 30-amp 120V outdoor branch circuits where the current capacity requires 10 AWG conductors but the application does not need 240V operation. As a 10/2 direct burial cable, this product features two insulated 10 AWG copper conductors (one hot, one neutral) plus a bare copper ground, configured for 120V single-phase circuits only. As 30 amp 120V underground wire, the Southwire 10/2 UF-B handles the outdoor electrical applications that require higher current capacity than 14/2 UF-B can deliver: RV plug installations (30A 120V is the most common RV plug configuration), heavy outdoor receptacles for large equipment, workshop 30A 120V circuits, and outdoor lighting circuits that need extra capacity or extra voltage-drop headroom on long runs. As Southwire 13056755, this specific SKU fills the important middle position in the Southwire UF-B lineup between the lighter 14/2 UF-B (15-amp 120V applications) and the heavier 10/3 UF-B (30-amp 240V applications), providing the right specification when 30-amp capacity is needed but 240V operation is not. As a UF-B 10 AWG 2 conductor cable, the Southwire 10/2 UF-B uses the same solid PVC fill construction and sunlight-resistant moisture-resistant gray jacket as the smaller and larger UF-B siblings, allowing direct burial without conduit and the labor savings that come with it. Every Southwire 10/2 UF-B 250 ft roll ships nationwide from IB Lighting with free freight. Manufacturer specifications are available at the official Southwire website.

Southwire 10/2 UF-B Key Highlights

10/2 Configuration: Two Conductors Plus Ground

The Southwire 10/2 UF-B contains three conductors total: two insulated 10 AWG conductors (one black, one white) plus a bare 10 AWG copper grounding conductor. Understanding what each conductor does helps you wire the cable correctly at both ends of the run.

The three conductors serve specific roles in 120V circuit operation:

• Black conductor: The hot conductor that carries the 120V supply current from the panel to the load equipment.
• White conductor: The neutral conductor that carries the return current from the load equipment back to the panel.
• Bare copper conductor: The equipment grounding conductor that provides the safety fault path for ground-fault current return.

This two-conductor-plus-ground configuration is identical to the Southwire 14/2 UF-B configuration, just at a larger gauge for higher current capacity. The cable operates as a standard 120V single-phase branch circuit, with the 30-amp capacity being the differentiator from the 14/2 UF-B’s 15-amp capacity.

The 10/2 UF-B does NOT include a second hot conductor (red), which is the structural difference from the 10/3 UF-B. Because there is no second hot leg, the cable cannot provide 240V operation regardless of how it is terminated. This limitation is the defining characteristic of the 10/2 configuration and is the most important point to verify before specifying this cable for any project.

10/2 vs 10/3: The Critical Voltage Difference

The most important distinction for residential outdoor wire selection is between the Southwire 10/2 UF-B (this product) and the Southwire 10/3 UF-B. These two products share the same gauge (10 AWG, 30-amp circuit capacity) but serve fundamentally different applications because of the conductor configuration.

Southwire 10/2 UF-B (this product): Two conductors plus ground (one hot, one neutral, one bare copper ground). Serves 120V single-phase circuits ONLY. Cannot power any 240V equipment regardless of termination. Right for: RV plugs (30A 120V), heavy outdoor receptacles, large workshop 120V equipment, outdoor lighting needing voltage-drop headroom.

Southwire 10/3 UF-B (sister product): Three conductors plus ground (two hots, one neutral, one bare copper ground). Serves either 120V circuits (using one hot, neutral, ground) OR 240V circuits (using both hots and ground) OR mixed 120/240V applications (using all four conductors for subpanels). Right for: hot tubs (240V/30A), detached garage subpanels, well pumps (most are 240V), pool equipment, any application requiring 240V operation.

The decision tree is simple but critical to follow correctly:

• Is the application 240V? If yes, use 10/3 UF-B. The 10/2 cannot provide 240V regardless of how it is wired.
• Is the application 120V at 30A? Use 10/2 UF-B (this product). It is appropriately sized and lower-cost than the 10/3.
• Does the application require BOTH 120V and 240V loads (typical detached subpanel)? Use 10/3 UF-B. The 10/2 cannot serve subpanels with 240V loads.
• Is the application a hot tub or spa? Use 10/3 UF-B (most residential hot tubs are 240V/30A or larger).

For projects requiring 240V capability, browse the Southwire 10/3 UF-B Direct Burial Cable 250 ft. The price premium for the 10/3 over the 10/2 reflects the additional insulated conductor and broader application capability. Specifying the 10/2 for an application that actually needs 240V means the cable will need to be replaced before the equipment can be installed, an expensive correction to avoid through correct specification at the start.

Why the Southwire 10/2 UF-B Cannot Serve 240V Applications

The single most important specification fact about the Southwire 10/2 UF-B is that it cannot serve 240V applications regardless of how the cable is terminated or what equipment it is connected to. Understanding why this is true (rather than treating it as an arbitrary specification) helps prevent expensive mistakes during project planning.

Residential 240V power in the US comes from two hot legs of the split-phase electrical service, with each leg providing 120V to ground but 240V between the two legs. To deliver 240V to outdoor equipment, the cable must contain TWO hot conductors that connect to opposite phases of the split-phase service at the panel. The 240V appears between these two hot conductors at the destination equipment.

The Southwire 10/2 UF-B contains only ONE hot conductor (the black wire) plus a neutral (white) and ground (bare copper). There is no second hot conductor available, so it is physically impossible to provide 240V from this cable. Connecting the cable to a 240V breaker at the panel would not change this; the cable would deliver 120V to ground from the single hot conductor and nothing else.

For applications that require 240V operation, the cable must contain two hot conductors. Common 240V residential applications include:

• Hot tubs and spas: Typically 240V/30A or 240V/40A. Requires 10/3 or 8/3 UF-B.
• Well pumps: Most submersible well pumps operate at 240V. Requires 10/3 or larger UF-B.
• Pool equipment: Pool pumps, heaters, and similar equipment typically operate at 240V. Requires 10/3 or larger UF-B.
• Detached garage/workshop subpanels: Subpanels serve both 120V and 240V loads. Requires 10/3 or larger UF-B.
• Electric vehicle chargers (Level 2): 240V operation. Requires appropriate gauge UF-B (typically 6/3 or larger for 48-amp chargers).

For any of these applications, the Southwire 10/2 UF-B is the WRONG specification. Verify the voltage requirement of your specific equipment before committing to the 10/2 versus 10/3 choice.

Common Applications for the Southwire 10/2 UF-B

The Southwire 10/2 UF-B serves specific residential outdoor electrical applications that require 30-amp current capacity at 120V. Understanding the right applications helps confirm the 10/2 specification matches your specific project.

The most common applications for the Southwire 10/2 UF-B in residential settings:

• RV plug installations (30A 120V): The standard residential RV plug is the TT-30 receptacle providing 30 amps at 120V, used by most travel trailers and smaller RVs. The Southwire 10/2 UF-B is the correct cable specification for the underground feeder from the house panel to the RV plug receptacle.
• Heavy outdoor receptacles: Outdoor 30A 120V receptacles for large equipment, contractor tools, food trucks, or other high-current 120V applications that exceed standard 15A or 20A receptacle capacity.
• Workshop and shed 30A 120V circuits: Dedicated 30-amp 120V circuits for large workshop equipment that operates at 120V (some compressors, large bench equipment, multiple ganged tools on one circuit).
• Outdoor lighting on long runs: Large outdoor lighting installations covering long distances where the 30-amp capacity provides voltage-drop headroom that 15-amp 14/2 UF-B could not deliver reliably.
• Pond pumps, fountains, large irrigation pumps: Some pond and water feature equipment operates at 120V with 25-30A current draw, requiring 30A circuits delivered via 10 AWG conductors.
• Festival/event temporary outdoor circuits: Some outdoor event and festival electrical installations require 30A 120V circuits for vendor stalls, food preparation equipment, or other high-current 120V loads.
• Detached structure dedicated equipment circuits: Specific dedicated equipment circuits at small detached structures where 30A 120V is the right capacity for the specific equipment without needing a full subpanel.

For 240V applications (hot tubs, well pumps, pool equipment, detached subpanels), the Southwire 10/2 UF-B is NOT the right specification regardless of the matching current capacity. Use the Southwire 10/3 UF-B for any application requiring 240V operation.

RV Plug and 30A 120V Receptacle Circuits

RV plug installations are one of the most common applications for the Southwire 10/2 UF-B in residential settings. Understanding RV plug specifications helps clarify why the 10/2 is the right cable for this application specifically.

The standard residential RV plug receptacle is the NEMA TT-30R (Travel Trailer 30-amp receptacle), which provides 30 amps at 120V. This is the most common RV plug configuration used by smaller travel trailers, pop-up campers, and many fifth-wheels. The TT-30 plug has three blades: one hot, one neutral, one ground, all at 120V single-phase.

For a TT-30 RV plug installation, the Southwire 10/2 UF-B is the correct cable specification because:

• 30-amp current capacity: The 10 AWG conductors handle the 30-amp continuous load capacity required for the TT-30 receptacle.
• 120V single-phase: The two-conductor (hot + neutral) configuration matches the TT-30 plug specification.
• Underground routing: RV plug locations are typically in driveways, parking areas, or pads located some distance from the house, requiring underground feeder routing.

For larger RVs that require 50A service (typical for larger Class A motorhomes and large fifth-wheels), the NEMA 14-50R receptacle is used instead, which provides 50 amps at 240V (with the trailer using either side of the 240V for 120V loads internally). The 14-50R requires a 6/3 UF-B cable, which is significantly larger and more expensive than the 10/2. Verify the RV’s specific plug requirement before committing to the cable specification: 30A 120V uses 10/2 UF-B, 50A 240V uses 6/3 UF-B.

For other 30A 120V outdoor receptacle applications (heavy equipment plugs, contractor tool receptacles, food truck connections), the Southwire 10/2 UF-B handles the cable run from the panel to the outdoor receptacle box. The receptacle itself, the weatherproof enclosure, and any required disconnect hardware are separate purchases.

Voltage Drop Advantage on Long 120V Runs

One of the most important practical advantages of the Southwire 10/2 UF-B over the smaller 14/2 UF-B is the meaningfully lower voltage drop on long underground runs. Understanding voltage drop helps clarify when the 10/2 specification is needed versus when 14/2 would be adequate.

Voltage drop occurs because every cable has electrical resistance proportional to its length. As current flows through the cable, some voltage is “lost” overcoming this resistance, with the result that the voltage delivered at the far end of the cable is lower than the voltage at the panel end. For long runs, the voltage drop can become significant enough to affect equipment operation.

Typical voltage drop characteristics for 120V circuits:

• 14 AWG at 15A over 100 feet: Approximately 4.5 volts drop (3.75%). At the upper edge of acceptable for sensitive equipment.
• 14 AWG at 15A over 200 feet: Approximately 9 volts drop (7.5%). Exceeds NEC recommendations.
• 14 AWG at 15A over 300 feet: Approximately 13.5 volts drop (11.25%). Likely problematic for equipment operation.
• 10 AWG at 30A over 100 feet: Approximately 3.5 volts drop (2.9%). Comfortably within recommendations.
• 10 AWG at 30A over 200 feet: Approximately 7 volts drop (5.8%). Still acceptable for most equipment.
• 10 AWG at 30A over 300 feet: Approximately 10.5 volts drop (8.75%). Approaching the edge of acceptable.

For 120V outdoor circuits where the run distance is long (typically over 100 feet from the panel to the destination), the Southwire 10/2 UF-B provides meaningful voltage-drop headroom over equivalent 14/2 UF-B even when the current draw is lower than the cable’s 30-amp rating. Some installers specifically choose 10/2 for long outdoor lighting runs at 15A actual current draw because the voltage drop performance is much better than 14/2 would deliver at the same current.

NEC voltage drop guidelines: branch circuit voltage drop should generally be limited to 3% (3.6 volts on a 120V circuit), with combined feeder plus branch circuit voltage drop limited to 5% (6 volts on 120V). These are recommendations rather than absolute requirements, but they help guide the cable gauge selection for long runs.

Heavy Outdoor Lighting Installations

Large outdoor lighting installations are a meaningful application for the Southwire 10/2 UF-B, particularly when the installation involves long cable runs or large total wattage that benefits from the 30-amp circuit capacity.

Typical landscape lighting installations use a step-down transformer at a strategic yard location, with the 120V line-voltage cable from the panel feeding the transformer, and 12V low-voltage cable distributing power from the transformer to individual landscape lights. For most residential installations, the 14/2 UF-B handles the 120V portion adequately because the transformer typically draws under 15 amps. For larger landscape lighting installations with multiple transformers or a single very large transformer, the 30-amp capacity of the Southwire 10/2 UF-B becomes the right specification.

Line-voltage outdoor lighting installations (no step-down transformer; individual 120V outdoor fixtures direct-wired to the circuit) frequently benefit from the 10/2 UF-B specification when the installation includes many fixtures or when the run length is significant. A typical 100-watt outdoor light draws under 1 amp, so a 30-amp 120V circuit can serve approximately 25 such fixtures (with appropriate margin for code compliance and starting current). For installations needing this many outdoor lights distributed across a large property, the 10/2 UF-B handles the load with comfortable margin.

The voltage drop advantage of 10/2 UF-B becomes particularly important for outdoor lighting installations on large properties where the cable run from the panel to the lighting area may be 200+ feet. At these distances, the voltage drop on 14/2 UF-B would cause noticeable dimming on the lights at the far end of the circuit. The 10/2 UF-B maintains acceptable voltage at the far end even over long distances.

For typical small landscape lighting projects (single transformer, under 100 feet of line-voltage cable, modest total wattage), the smaller Southwire 14/2 UF-B is more appropriately sized and more affordable. The 10/2 UF-B specifically targets the larger installations where the additional cable cost is justified by the capacity and voltage-drop performance.

Direct Burial Code Requirements

The Southwire 10/2 UF-B is approved for direct burial underground without conduit protection in residential applications, the same as the other UF-B gauges. The same NEC depth requirements apply to all UF-B cables regardless of gauge.

NEC Article 300.5 depth requirements (apply to all UF-B gauges including the 10/2):

• Direct burial without conduit: Minimum 24 inches of cover.
• Direct burial under residential driveways: Minimum 18 inches plus 4 inches of concrete or equivalent above the cable.
• Direct burial under concrete slabs: Minimum 18 inches.
• Underground installation in PVC conduit: Minimum 18 inches of cover.
• Underground installation in rigid metal conduit: Minimum 6 inches of cover.

For typical residential 30-amp 120V outdoor circuit installations using the Southwire 10/2 UF-B, the 24-inch depth requirement governs the trench excavation. In cold climates, bury below the local frost line (which often exceeds 24 inches in northern US regions) to prevent ground heaving damage from winter freeze-thaw cycles.

The 10/2 UF-B is somewhat larger in diameter than the 14/2 UF-B, but smaller than the 10/3 UF-B (which contains an additional insulated conductor). Trench width and depth requirements are based on cable depth not diameter, so the same standard residential trench dimensions handle all UF-B gauges identically.

GFCI Protection for Outdoor 30-Amp Circuits

Outdoor circuits served by the Southwire 10/2 UF-B typically require GFCI protection per NEC Article 210.8 (outdoor receptacle circuits) and other applicable code sections. Understanding the GFCI requirement helps you plan the complete code-compliant installation.

For 30-amp 120V circuits served by the Southwire 10/2 UF-B, GFCI protection is typically provided by:

• 120V GFCI breaker at the main panel: A 30-amp 120V GFCI breaker installed in the panel protects the entire downstream circuit. This is the most common approach for outdoor 30A circuits.
• GFCI receptacle at the destination: A 30-amp GFCI receptacle at the outdoor location provides GFCI protection at the receptacle itself. Less common for 30A applications because 30A GFCI receptacles are less universally available than standard 15A or 20A GFCI receptacles.

One specific RV plug consideration: the TT-30 RV receptacle is required to be GFCI-protected per current NEC. The most practical approach is a 30-amp 120V GFCI breaker at the panel feeding the Southwire 10/2 UF-B underground feeder. Some installers use a dedicated GFCI loadcenter or auxiliary panel at the RV plug location, which adds materials cost but provides GFCI protection at the destination rather than at the main panel.

For 30-amp 120V circuits serving non-receptacle loads (direct-wired equipment, lighting installations without receptacles), GFCI protection may or may not be required depending on the specific application and current NEC adoption. Verify the specific GFCI requirement for your installation with current NEC or your local electrical inspector.

Southwire 10/2 UF-B Specifications

Southwire 10/2 UF-B FAQs

Who the Southwire 10/2 UF-B Is Built For

The Southwire 10/2 UF-B serves four clear buyer types in residential outdoor electrical work. The first is homeowners installing 30A RV plugs on their property for travel trailers and smaller RVs. For these buyers, the Southwire 10/2 UF-B is the correct specification for the standard residential TT-30R RV plug installation, and the 250-foot roll matches typical RV plug feeder run consumption.

The second buyer is electrical contractors handling heavy outdoor receptacle installations for food trucks, contractor equipment plugs, festival electrical setups, and similar applications requiring 30A 120V capacity. For these contractors, the Southwire 10/2 UF-B handles the underground feeder portion of these installations efficiently.

The third buyer is outdoor lighting installers running large landscape lighting installations on bigger properties where the 30-amp capacity and voltage-drop headroom of 10/2 UF-B is needed. For these installers, the cable handles long-distance line-voltage feeds to transformer locations or directly to multiple-fixture lighting installations.

The fourth buyer is the workshop and detached structure electrician installing dedicated 30A 120V equipment circuits to small outbuildings, sheds, or detached structures that need higher current capacity than 14/2 UF-B but do not require 240V operation. For these projects, the Southwire 10/2 UF-B is the right specification at lower cost than the 10/3 alternative. Browse the broader IB Lighting electrical wire collection for related products.

Southwire 10/2 UF-B vs 14/2 UF-B: When the Heavier Gauge Wins

The choice between the Southwire 10/2 UF-B (this product) and the smaller Southwire 14/2 UF-B is driven by current capacity requirements and run distance. Both serve 120V single-phase outdoor circuits, but at different capacity levels.

Choose the Southwire 10/2 UF-B (this product) when: the circuit requires 30-amp capacity (RV plugs, heavy outdoor receptacles, workshop 30A equipment), the run distance exceeds 100 feet and voltage drop on 14/2 would be problematic, the installation includes many outdoor lighting fixtures or high total wattage that approaches 14/2 limits, or the application specifically calls for 10 AWG conductors per code or equipment specification.

Choose the Southwire 14/2 UF-B when: the circuit is a standard 15-amp branch (landscape lighting, small outdoor receptacles, small detached shed feeders), the run distance is moderate (under 100 feet typically) so voltage drop is not a concern, the total current draw is well within 15-amp limits, and budget considerations favor the lower-cost 14/2 specification.

The price difference is meaningful: the 14/2 UF-B at $120 for 250 feet ($0.48/ft) versus the 10/2 UF-B at $325 for 250 feet ($1.30/ft) reflects the larger conductor diameter. The 10/2 is approximately 2.7 times the cost per foot of 14/2, justified only when the application genuinely needs the higher current capacity or voltage-drop performance.

Installation Best Practices for the Southwire 10/2 UF-B

Installing the Southwire 10/2 UF-B for 30-amp 120V outdoor circuits follows the same general practices as smaller UF-B installations, with considerations specific to the higher current capacity and somewhat thicker cable diameter.

Plan the GFCI protection: Outdoor 30-amp 120V circuits typically require a 30-amp 120V GFCI breaker at the main panel. Identify the correct GFCI breaker brand and configuration for your specific panel before starting work. GFCI breakers are more expensive than standard breakers and may require specific availability checks.

Trench depth and routing: The 24-inch minimum depth applies to all UF-B installations. The slightly larger 10 AWG cable diameter does not change the trench depth requirement. Plan the route to minimize landscape impact and verify depth compliance before backfill.

Use appropriately sized terminations: The 10 AWG conductors require larger wire-nut, lug, or device terminations than smaller gauge conductors. Standard 15-amp residential terminations may not be rated for 10 AWG conductor diameter. Use appropriately sized terminations throughout the installation.

Box fill considerations: The thicker 10 AWG conductors increase the volume fill at electrical boxes. Standard residential boxes that handle 14/2 UF-B may not have adequate volume for 10/2 UF-B terminations, especially when combined with devices and switches. Use appropriately sized boxes throughout.

Voltage drop calculations for long runs: For runs over 100 feet at 30A, voltage drop should be calculated to verify acceptable performance at the destination. Standard rule-of-thumb: keep voltage drop under 3% for branch circuits, which becomes the practical limit on 10/2 UF-B at 30A for runs of approximately 100 feet. Longer runs may require larger gauge cable or reduced current loading.

Transition properly at above-grade terminations: Where the Southwire 10/2 UF-B emerges from the ground at the destination receptacle or equipment location, transition the cable into rigid metal conduit or equivalent physical protection. The transition typically extends from below grade to at least 8 feet above grade or into the protective enclosure.

Test before final backfill: Verify circuit operation including GFCI function before final backfill. Once the trench is backfilled, repairs become significantly more expensive. The test step adds minimal time and prevents many post-install issues.

Browse the complete IB Lighting electrical wire and cable collection, step up to Southwire 10/3 UF-B for 240V applications, step down to Southwire 14/2 UF-B for 15-amp outdoor circuits, explore other Southwire products, consider a Generac standby generator for backup power that keeps outdoor circuits running during outages, or visit our customer FAQ hub. Manufacturer technical sheets are available at the official Southwire website.