In electrical wiring projects, a single decision - choosing between MC Cable (Metal-Clad Cable) and AC Cable (Armored Cable) - can directly impact safety, reliability, and cost.
Have you ever wondered why some projects specify MC Cable while others insist on AC Cable?
This article will walk you through their fundamental differences, applications, and selection strategies - and at the end, show you why Dongguan Greater Wire & Cable Co., Ltd. is your trusted partner for quality, compliance, and service excellence.
What Are AC Cable and MC Cable?
What Is AC Cable (Armored Cable / BX Cable)?
- Definition & Standards
AC Cable, often referred to as BX Cable, is a type of metal-armored electrical cable where the conductors and insulation are protected by an interlocked metallic sheath. It is defined under NEC Article 320.
- Structure Features
Conductors + Insulation: Usually copper or aluminum conductors with thermoplastic insulation.
Armor Layer: A spiral or interlocked metal tape that provides mechanical protection.
Grounding: AC Cable does not contain a separate grounding conductor. Instead, it uses a bare aluminum bonding strip combined with the metal sheath as the grounding path.
- Application Environments
AC Cable is generally used indoors and in dry locations. It is not recommended for wet, outdoor, or direct-burial applications because standard AC cables lack moisture resistance or outer protective jackets.
What Is MC Cable (Metal-Clad Cable)?
- Definition & Standards
MC Cable, regulated under NEC Article 330, represents a more modern and flexible evolution of armored wiring, designed for broader use and improved grounding reliability.
- Structure Features
Conductors + Insulation: High-quality thermoplastic insulation such as polypropylene or Mylar tape.
Armor Layer: Interlocked aluminum or steel metallic sheath.
Independent Grounding Conductor: MC Cable includes a dedicated bare or green insulated grounding wire, making the system safer and more versatile.
Optional Protective Jacket: For outdoor, damp, or direct-burial use, MC Cable can include a PVC or polyvinyl chloride outer jacket for additional protection.
- Application Environments
MC Cable is suitable for indoor, outdoor, wet, and even direct-burial environments when properly rated and jacketed.
Key Differences Between MC and AC Cable
The following comparison table helps you clearly understand the essential distinctions:
| Feature | AC Cable (Armored Cable / BX) | MC Cable (Metal-Clad Cable) |
|---|---|---|
| Grounding | Uses a bare aluminum bonding strip and metal sheath as grounding path | Includes a full-size grounding conductor (bare or green wire) inside the cable |
| Armor Type | Interlocked metallic tape or tube | Interlocked metal sheath, optionally with outer jacket |
| Protective Jacket | Not available on standard AC Cable | Optional PVC jacket for wet or outdoor use |
| Application Environment | Indoor, dry only | Indoor, outdoor, wet, or direct burial (if rated) |
| NEC Standard | Article 320 | Article 330 |
| Installation Flexibility | Less flexible; limited bending radius | More flexible; easier for complex routing |
| Support Spacing | Typically every 4.5 ft (1.37 m) | Can be extended to 6 ft (1.83 m) between supports |
| Cost | Lower initial cost | Slightly higher cost, but greater versatility |
| Ground Continuity | Relies on armor; may be interrupted if improperly installed | Reliable, independent grounding path |
| Outdoor / Wet Use | Not suitable | Suitable when properly jacketed and rated |
👉 In short: MC Cable is a more advanced, flexible, and safer option for modern installations, especially in demanding or exposed environments.
Typical Application Scenarios
Where MC Cable Excels
- Industrial Facilities & Manufacturing Plants
Ideal for environments with vibration, moisture, and potential mechanical impact. MC Cable ensures long-term reliability and consistent grounding.
- Commercial Buildings & High-Rises
In office towers, hospitals, and shopping centers with complex electrical layouts, MC Cable simplifies installation while enhancing safety.
- Outdoor & Exposed Wiring
For outdoor conduit, cable trays, and partial direct-burial routes, MC Cable with protective jackets is the superior choice.
- Retrofit or Expansion Projects
Flexible and adaptable, MC Cable performs well in renovation projects requiring rerouting through existing structures.
Where AC Cable Fits Best
- Residential and Light Commercial Interiors
Perfect for dry indoor walls and ceilings where flexibility and low cost are priorities.
- Ceiling Trays and Concealed Runs
Suitable for controlled environments with stable temperature and humidity.
- Budget-Sensitive Projects
AC Cable offers cost-effective wiring for smaller jobs when conditions are dry and straightforward.
✅ Summary:
- Use AC Cable for simple, dry indoor runs where budget matters.
- Choose MC Cable for safety-critical, complex, or outdoor environments.
How to Choose the Right Cable Type (with Case Studies)
Choosing between MC and AC Cable requires balancing environment, code compliance, installation convenience, and long-term maintenance.
Case 1: High-Rise Office Building - "Balancing Cost & Safety"
Background:
A 30-story office tower project needed multiple power distribution circuits per floor. Most wiring was routed through ceiling trays and wall cavities.
Analysis:
- Environment: mostly dry and controlled - AC Cable could reduce material cost.
- However, main feeders and shafts required robust grounding and occasional exposure to humidity.
- Future modifications were expected.
Recommendation:
Use AC Cable for dry, enclosed runs, and MC Cable (with jacket) for risers, basements, and semi-exposed areas.
→ Balanced solution combining cost efficiency and safety compliance.
Case 2: Municipal Wastewater Treatment Plant - "Harsh Conditions, Zero Compromise"
Background:
The facility required cabling across multiple zones - wet rooms, pump houses, outdoor trays, and chemical dosing areas.
Analysis:
- High humidity, corrosive atmosphere, and outdoor exposure.
- Safety and grounding reliability were top priorities.
- Maintenance access was limited.
Recommendation:
Adopt PVC-jacketed MC Cable throughout the site. Its dedicated grounding wire, corrosion resistance, and water protection ensured long-term reliability.
→ MC Cable became the only practical solution for performance and compliance.
Why Choose Dongguan Greater Wire & Cable Co., Ltd.?
Now that you know how MC and AC Cable differ, here's why we are your ideal partner for sourcing premium electrical cables.
Comprehensive Product Range & Certified Quality
- Full portfolio of MC Cable, AC Cable, and custom variants for all voltage classes and environments.
- Manufactured under strict quality control, compliant with UL, NEC, ISO, and IEC standards.
- Stable supply chain ensures consistent quality and on-time delivery.
Expert Technical & After-Sales Support
- Our technical team helps you evaluate environments, load requirements, and standards to select the right cable type.
- Support through every phase - design, order, installation, and maintenance.
- After-sales service available for troubleshooting, warranty, and training.
Flexible Production for Projects of Any Size
- Capable of handling both large-scale industrial projects and small custom orders.
- Services include cut-to-length, labeling, and custom packaging.
- Fast production turnaround to meet urgent deadlines.
Competitive Pricing & Reliable Lead Time
- Large-scale manufacturing enables high quality at competitive prices.
- Strong logistics and warehouse capacity ensure consistent delivery performance.
Contact Us Today
If you're planning an electrical project and need guidance on MC vs. AC Cable selection, grounding safety, or compliance issues, our experts are ready to assist.
- Dongguan Greater Wire & Cable Co., Ltd.
- Tel / WhatsApp / WeChat: +86 135 1078 4550 / +86 136 6257 9592
- Email: manager01@greaterwire.com
Whether your project is large or small, we deliver professional products, technical expertise, and reliable service - helping you build safer, smarter, and more efficient power systems.