Kimbluth 14/3 Metal Clad (MC) Cable with Ground 50ft, 14 Gauge Electric Wire with Aluminum Armor, Solid Bare Copper Conductors for Indoor Outdoor Underground Embedded Installation

Why I reached for this cable

I needed a rugged 15A branch circuit to feed exterior lighting and a couple of weatherproof receptacles on a detached shed. The run included a short exterior surface segment, a transition into buried conduit, and a clean termination inside a small sub‑junction box. I wanted something more durable than NM‑B and less fussy than building a conduit system for the entire route. The 14/3 MC cable from Kimbluth fit the bill on paper: interlocked aluminum armor, three insulated 14 AWG copper conductors plus a grounding conductor, 600V, 90°C rating, and UL listings for MC construction.

After a full install—cutting, bending, terminating, strapping, and testing—I came away impressed with the build quality, with a few caveats around code use and expectations for “underground” applications.

Build and materials

• Jacket and armor: The interlocked aluminum armor is consistent and tightly wound, with a clean seam that resists snagging on sharp box edges. Aluminum armor is inherently corrosion resistant and completely indifferent to sunlight, which is helpful for exterior runs.
• Conductors: Inside are three insulated 14 AWG copper conductors and a grounding conductor. The insulation feels like standard thermoplastic suitable for 90°C applications. The copper is solid (as is common for 14 AWG in MC), which makes devices and screw terminals straightforward, if a bit stiffer in tight boxes than stranded.
• Dimensions: The cable measures about 11.9 mm (roughly 0.47 in) in outside diameter. That’s compact for MC, and it fits common 3/8 in MC connectors nicely. Minimum bend radius for interlocked MC is typically 7× OD; for this cable that’s about 3.3 inches, which is achievable without kinking.
• Markings: The print on the armor is legible, carrying the pertinent UL references. I didn’t see smeared or inconsistent printing—helpful when inspectors want to read it in place.

The cable arrived in a tidy coil with a pair of straps. It uncoiled cleanly with minimal memory; I was able to get straight runs along siding using spaced clamps without fighting it.

Installation experience

I laid out a typical path: meter/main to exterior LB, surface‑run up the wall under a drip edge, then into PVC conduit for the underground portion. From there, the cable re‑emerged into a shed junction box for distribution to a GFCI, a photo‑controlled lighting circuit, and a switch loop.

• Cutting and prep: A dedicated MC cutter (Roto‑Split style) made quick, clean cuts without scoring the insulation. A hacksaw works in a pinch, but you risk nicking conductors. I recommend anti‑short bushings at terminations even when not strictly required—cheap insurance against abrasion where the armor ends.
• Connectors and fittings: Standard 3/8 in MC connectors gripped the armor securely. Bonding screws bit reliably, and the armor didn’t “walk” under clamp pressure. I used listed transition fittings to enter conduit where needed; anytime you’re mixing wiring methods, make sure each transition is mechanically secure and electrically continuous.
• Bending and routing: The cable is flexible enough to navigate modest offsets and back‑to‑back boxes without wrinkling the armor. Compared to EMT, it’s faster to route on irregular exterior surfaces; compared to NM‑B, it’s far more tolerant of the knocks and scrapes that happen outside.
• Strapping: Rubber‑cushioned 1/2 in clamps held the 0.47 in OD snugly and looked tidy on the exterior wall. If you want a tighter visual line, use continuous strap for long runs.

Terminations at devices felt familiar: solid 14 AWG seats well under captive screws, and the color coding made multi‑wire terminations easy to keep straight. The grounding conductor gives you a direct bond path; I still bonded the armor via listed fittings at metal enclosures for completeness.

Code and use context

A key point that deserves attention: “underground” does not always mean “direct burial.” This MC cable’s construction and listings support use in dry and many wet locations, but typical aluminum‑armored MC is not listed for direct burial in soil by itself. If you plan any below‑grade segment, the best practice is to transition into a raceway (PVC or similar) that is rated for burial, with correct depth and backfill per code. That’s the approach I took: MC above grade, conduit below grade.

Outdoors, the armor shrugs off UV and offers good mechanical protection. For corrosive environments (coastal salt spray, chemical plants), aluminum armor is often fine, but verify compatibility with your specific environment and fittings. For true marine or shipboard use, different listings usually apply; I wouldn’t spec this for ABYC/USCG applications without documentation to match.

As always, check local amendments to the NEC, and match the circuit’s ampacity to the weakest link. Even with 90°C conductors, a 14 AWG copper branch circuit is still a 15A circuit under 240.4(D).

Performance and electrical characteristics

On a 120V, 15A lighting and receptacle branch, voltage drop was a non‑issue across the short run. For reference, 14 AWG copper is about 2.5 ohms per 1000 feet. Over 50 feet one‑way (100 feet round trip), that’s roughly 0.25 ohms. At a 10A load, the drop is about 2.5V—just a touch over 2%—well within acceptable limits for most residential and light commercial circuits. If you’re pushing longer distances or sensitive loads, plan your run lengths and loads accordingly.

Insulation resistance tested clean with a megohmmeter prior to energizing, and continuity was solid. Once in service, the circuit remained quiet on a clamp meter with no evidence of nuisance tripping or heating at terminations.

Mechanical protection is what you pay for here. The armor takes incidental impacts and resists rodent chewing far better than nonmetallic sheaths. On the exterior wall, I was comfortable not adding extra guard plates where the run was fully exposed and out of foot traffic.

Where it shines

• Exterior surface runs on wood or masonry where conduit would be slow and NM‑B isn’t permitted
• Short transitions between equipment where you want built‑in mechanical protection
• Temporary or semi‑permanent power distribution around a workshop, farm outbuildings, or jobsite (with proper fittings and support)
• Any 15A multi‑wire branch circuit where three current‑carrying conductors plus ground simplifies switching or shared neutrals

The 50‑foot length is practical. It’s long enough for many small projects and spares you from buying a large reel and cutting wastefully.

Limitations and considerations

• Not for direct burial: Plan on conduit for underground segments unless you have documentation explicitly listing the cable for direct burial.
• Stiffer than NM‑B: Fishing through finished walls is harder. For remodel work inside finished spaces, NM‑B or flexible conduit with THHN/THWN conductors can be easier.
• Solid conductors: Solid 14 AWG is standard here, but in tight or vibration‑prone terminations, stranded can be more forgiving. This is more a preference than a defect.
• Box fill: Check cubic inch capacity, especially if you’re using all three current‑carrying conductors. MC doesn’t give you a free pass on box fill math.

Value and quality

At this length and gauge, the cable hits a sensible sweet spot: purpose‑built protection without over‑buying. The armor is clean, the conductors are true copper, and the overall assembly feels consistent and reliable. Importantly, the dimensional stability makes fittings predictable—connectors seat square, clamps hold, and you don’t fight misshapen ends.

Practical tips

• Use a proper MC cutter and anti‑short bushings at every termination.
• Pre‑plan transitions between wiring methods, especially at grade changes.
• Strap generously; the run looks cleaner and resists oscillation in wind.
• Mark the neutral and shared circuits clearly if you build a multi‑wire branch circuit.

Recommendation

I recommend the Kimbluth 14/3 MC cable for 15A branch circuits that need durable mechanical protection, especially on exterior surfaces and in utility spaces where conduit would be overkill. It installs cleanly, mates well with standard 3/8 in MC connectors, and the aluminum armor provides real‑world toughness without undue weight. Just be mindful that “underground” should be accomplished in a listed raceway unless the cable is specifically marked for direct burial. Within those constraints, it’s a dependable, code‑compliant way to harden light‑duty circuits and keep them looking tidy and professional.