If diamonds are a girl’s best friend, then metal clad (MC) cable might just be an electrician’s partner of choice.
Metal clad cables can be found in many locations, including indoors, outside, and even underground. This cable is durable and flexible, making it an excellent choice for service, feeder, and branch circuits and across commercial, industrial, and residential applications.
Type MC cables work well in Class I, Division I hazardous locations (these are called MC-HL cables), healthcare facilities, theaters, assembly plants, and power and lighting control. Despite its aluminum armor, it can also be used in wet locations but needs to have a PVC jacket for protection. A list of potential applications is outlined in National Electrical Code (NEC) Article 330.
For most applications, the typical MC cable will range from #14 to #10 AWG but can be as large as 2,000 MCM in some cases.
According to the NEC, a metal clad cable is “a cable in which the conductors are enclosed in a corrugated metal sheath or interlocking metal tape, insulated, and the entire cable is put together at the factory.”
It can include one or more insulated conductors, including one full-size ground wire, and features one of several types of armor sheathing.
Once you’ve selected your armor type, you’ll also have to determine what voltage the application will require. Manufacturers use different jacket colors to differentiate MC cables from one another, including:
Metal clad cable is durable, flexible, and ready to use as soon as it reaches the job site. As a result, it’s an excellent choice for electricians who want to save time and reduce labor hours.
The armored cable has a flexible casing, making it easier to bend around corners and fit into tight or concealed spaces. It also protects internal conductors from fire, prevents damage due to abrasion or impact, provides environmental protection from wildlife and weather, and can block out some electromagnetic interference.
Another reason MC cable is so popular with electricians is that it doesn’t need a conduit. Unlike cables that need to be lubricated and pulled through winding conduit pathways, metal clad cable only needs to be supported every few feet. This can be done using a cable tray or staples, cable ties, straps, or hangers. Without conduit to worry about, installers save tons of time running MC cable because it essentially does the same thing.
Remember, metal clad cables can only be used with metal electrical boxes! Other box types like fiberglass or plastic won’t work because they aren’t designed for that use and will fail an electrical inspection. According to NEC guidelines, the reason is that there is no way to maintain the electrical continuity of the effective ground-fault current path.
With a naked eye, it’s tough to tell the difference between a metal clad cable and a standard armored cable. However, as my mother always tells me, “It’s what’s on the inside that counts.”
The standard AC cable includes:
A standard MC cable includes:
When everything is contained within one cable, it makes sense why electricians choose to work with MC cable when they have the chance.
It’s a cost-effective, time-saving product that works in multiple locations and doesn’t have the same limitations associated with products that need to be pulled through conduit. Thanks to its flexibility, it can bend easier than conduit installations and fit into tight spots and concealed areas more safely.
For crews, that means less time spent pulling wire, fewer workers needed to get the job done, and cleaner installations.