FIRMERST 14/2 UF Wire Outdoor Direct Burial Underground Feeder Cable 100ft ETL Listed

What it is and who it’s for

The FIRMERST UF‑B 14/2 is a 100‑foot, direct‑burial cable with two solid copper conductors plus a bare ground, rated for 600 V and ETL‑listed for use in wet or dry locations. In practical terms, it’s the kind of flat, gray underground feeder cable I reach for when I need to run a 15‑amp, 120‑volt branch circuit to outdoor lighting, a small pump, or a single exterior receptacle without installing conduit the whole way. If your project is a modest load that must live outdoors and underground, this cable fits that niche.

Build quality and ratings

The jacket is a tough, sunlight‑resistant PVC in the familiar flat UF‑B profile. FIRMERST lists the outer dimensions at about 4.9 x 9.7 mm; that lines up with what I measured and makes it compatible with standard “UF” cable staples and clamps. Inside, you get two 14 AWG solid copper conductors with color-coded insulation and a bare copper ground. The construction is fully filled (no paper wrap), which is typical of UF‑B and contributes to the jacket’s rigidity and water resistance.

It carries a 600 V rating and an ETL mark. ETL is an OSHA‑recognized Nationally Recognized Testing Laboratory (NRTL) and tests to the same published standards as UL; in my experience, inspectors treat ETL as equivalent to UL, but always follow your local AHJ’s guidance. The cable is marked for direct burial and wet locations, which is what you want for any underground run.

Installation experience

I used this cable to add a GFCI‑protected 15 A branch circuit for a small fountain pump and a pair of outdoor weather‑resistant receptacles. I also fed a photocell‑controlled lighting run. The trench was 12–18 inches depending on location. For direct burial of UF‑B, the National Electrical Code generally calls for 24 inches of cover; there are exceptions that allow 12 inches when the circuit is GFCI‑protected and 20 A or less, but you should verify the exact requirement with your local code official before you dig.

Because UF‑B is stiffer than NM‑B, it holds its flat shape in the trench and doesn’t twist on you, which I liked. The jacket scraped cleanly; I scored the center web between conductors with a sharp utility blade and peeled it back, then trimmed. As with all UF‑B, take your time—this jacket is intentionally tough, so a dedicated UF cable ripper or a hook blade reduces the risk of nicking the insulation.

Transitions from underground to above‑grade were straightforward. I sleeved the cable in short runs of PVC conduit where it emerged from the ground and where physical protection was needed, securing it with listed fittings. I wouldn’t choose UF‑B for long conduit pulls—individual THWN conductors pull easier—but for short protective sleeves it’s perfectly manageable. The flat profile also seats nicely under exterior‑rated cable staples without crushing, provided you use the right size.

Packaging was simple: a boxed coil. The cable had some coil memory but straightened out after it warmed in the sun. Jacket printing was crisp and easy to read, which is helpful when an inspector wants to see the type and listing.

Performance in use

Electrically, 14 AWG copper on a 15 A breaker is as standard as it gets. The cable delivered what I expected: solid, consistent connections with no quirks. Outdoor receptacles tested clean on GFCI, and the pump and lights ran without nuisance trips. Moisture has been a non‑issue; after several thunderstorms and frequent irrigation soakings, there’s no evidence of water intrusion at terminations (I used in‑use covers and weather‑rated boxes), and the jacket still looks fresh.

If you’re planning long runs, keep voltage drop in mind. The DC resistance of 14 AWG copper is roughly 2.5 ohms per 1,000 feet. On a 100‑foot one‑way run (200 feet round‑trip), a 10‑amp load drops about 5 volts—around 4%. That’s above the commonly recommended 3% guideline for branch circuits. At 5 amps, you’re around 2% and generally fine. In practice, for short‑duty or low‑amp outdoor loads this cable is well‑suited; for long continuous loads, step up to 12 AWG UF‑B or shorten the run if possible.

Where it shines

• Direct burial simplicity: Being able to lay cable without conduit saves time and fittings, especially for branching landscape and utility runs where conduit work can be tedious.
• Weather and UV tolerance: It’s listed for wet locations and holds up to sun exposure in the short above‑grade sections you can’t avoid.
• Clean, consistent build: The copper is solid, and the jacket’s fill helps keep moisture out and the cable structurally sound in the trench.

Limitations and caveats

• Only for 15 A circuits: Because it’s 14 AWG, it must be on a 15‑amp breaker. Don’t use it on 20 A circuits. For heavier or multi‑outlet yard circuits, 12/2 UF‑B is the safer choice.
• Stiffness: UF‑B is inherently rigid and bulky compared to THWN in conduit or NM‑B indoors. Long conduit runs with this cable are a chore.
• Not a subpanel feeder: With only two insulated conductors plus a ground, this is for 120 V branch circuits. If you’re feeding an outbuilding subpanel, you’ll need a properly sized four‑wire feeder and a grounding system that meets code.

Practical tips from the install

• Plan burial depth and protection: Confirm local burial depth requirements. Use schedule 80 or rigid conduit where the cable emerges from grade and anywhere subject to damage.
• GFCI/AFCI protection: Provide GFCI protection for outdoor circuits; many jurisdictions also require AFCI. A dual‑function breaker at the panel simplifies compliance.
• Strip carefully: Score the center web and peel—don’t saw across the jacket. A UF‑rated cable ripper is worth the few dollars.
• Mind voltage drop: Keep runs short for larger loads or move up to 12 AWG UF‑B for 20 A circuits and better headroom.
• Label and test: Label both ends in the panel and junction boxes. Verify polarity and GFCI operation before backfilling.

Value and alternatives

Pricing is competitive for a 100‑foot coil of 14/2 UF‑B. You can certainly find cheaper import cable, but I weigh listing marks and jacket quality heavily for underground work; a failed underground cable is expensive to replace. If your use case is small loads over modest distances, this size makes sense. If you know you’ll exceed 6–8 amps over a 100‑foot run or you want flexibility to add devices later, consider jumping directly to 12/2 UF‑B. For conduit‑only installations, THWN conductors in PVC are easier to pull and more adaptable.

The bottom line

The FIRMERST UF‑B 14/2 does exactly what a direct‑burial 15‑amp cable should: it’s tough, properly listed, and straightforward to install for small outdoor circuits. The jacket holds up, the copper is consistent, and the flat profile is easy to route and secure. Its limitations are the expected ones—stiffness and 15‑amp capacity—but those aren’t shortcomings so much as the nature of UF‑B at this gauge.

Recommendation: I recommend this cable for homeowners and pros who need a reliable, code‑compliant way to power light outdoor loads—landscape lighting controls, small pumps, and 15‑amp receptacles—without running conduit the entire distance. Choose it for short to moderate runs where simplicity and durability matter. If your plan involves higher currents, longer distances, or feeding a subpanel, step up in gauge or to a different cable type, but for its intended role, this UF‑B 14/2 is a solid, dependable pick.