The Two Approaches Defined
Armored cable (MC/AC/BX) is a factory-assembled wiring method: conductors are insulated, cabled together, and enclosed in a metal armor (interlocked aluminum or steel) in a single product. You pull it, terminate it, done.
Conduit with conductors means installing empty tubing (EMT, IMC, RMC, PVC) first, then pulling individual conductors (typically THHN) through it after. Two separate steps, two materials.
Head-to-Head Comparison
| Factor | Armored Cable (MC) | Conduit + THHN |
|---|---|---|
| Install speed | Faster (one step) | Slower (two steps) |
| Material cost | Higher per foot | Lower per foot |
| Future rewire flexibility | Low (must replace whole section) | High (pull new conductors) |
| Mechanical protection | Good (armor protects) | Excellent (rigid conduit) |
| Wet locations | Requires MCWP or liquid-tight type | RMC/IMC rated for wet |
| Exposed hazardous areas | Requires ATEX/IECEx-rated type | RMC with approved fittings |
| Renovation/retrofit | Ideal (easy to route) | Harder in tight spaces |
| Multiple circuit changes | Expensive long-term | Cost-effective long-term |
NEC Code Guidance
NEC Article 330 covers Metal-Clad Cable (MC). Key permitted uses and restrictions:
- Allowed in dry and damp locations (wet requires listed type)
- Permitted in concrete if listed for that use
- Not permitted to be used as a service entrance conductor
- Requires anti-short bushings at every termination
- Maximum 6 ft of unsupported length at luminaire connections (NEC 330.30)
When Armored Cable Wins
- Renovation projects — Routing individual conduit through finished walls is impractical; MC cable snakes through existing cavities
- Short branch circuit runs — Under 50 ft where future circuit changes are unlikely
- Exposed installations requiring some mechanical protection — Warehouses, commercial kitchens where conduit would be over-engineered
- Above suspended ceilings — MC cable is NEC-permitted in accessible ceiling spaces
When Conduit + THHN Wins
- Industrial plants with frequent process changes — Conduit lets you pull new circuits without demolition
- Exposed outdoor installations — RMC/IMC provides superior UV and impact resistance
- High-voltage circuits (over 600V) — Conduit with listed conductors is the standard approach
- Long runs (>100 ft) — Conductor-only cost per foot is significantly lower; labor savings switch in favor of conduit
- Data centers and critical facilities — Conduit provides EMI containment and future bandwidth upgrades
Total Installed Cost: A Real Example
For a 75 ft, 20A, 120V branch circuit in a commercial office renovation:
- MC Cable (12/2 with ground): ~$0.85/ft material + $28/hr labor = ~$127 material + 1.5 hrs labor = ~$169 total
- ½" EMT + 12 AWG THHN: ~$1.10/ft conduit + $0.18/ft wire × 3 conductors + $28/hr labor = ~$137 material + 2.5 hrs labor = ~$207 total
In this scenario MC cable wins on total installed cost. But for a 200 ft industrial run with 6 future circuit changes planned, conduit wins easily due to conductor-only replacement costs.
Need Armored or Industrial Cable Factory-Direct?
Shanghai Unicorn supplies MC cable, armored industrial cable, and THHN building wire direct from our Shanghai factory. Custom lengths, gauge sizes, and UL/CSA listings. Volume pricing for distributors and contractors.