MC Cable is manufactured with THHN Wire conductors and a THHN wire ground as well. It has a Metal Clad aluminum jacket that allows for easy installation indoors without conduit. It's approved to be used indoors, outdoors and in conduit. MC Cable is NOT approved for direct burial but we do have UFB Cable and Tray Cable if you need it to be buried directly underground.
Our MC Cable is UL approved and manufactured to the Mil Spec AA59544.
MC cable is a standard type of electrical wire used indoors, outdoors, in conduit, directly underground and even buried in concrete if needed. The first type is an MC, metal clad, cable manufactured with THHN wire and an aluminum metal clad armor as a jacket. This type of electrical cable can not be used underground or in concrete but anywhere else is not a problem.
The second type of MC cable is called MC cable with PVC jacket. This is manufactured the same as the first cable with an additional PVC jacket that keeps the cable water and moisture tight. This cable is so strong it can be buried underground or in concrete for many years without a single problem.
MC cable and Romex® wire are both made with THHN conductors which commonly brings up the question: Why can't Romex® be used outdoors? The answer is that Romex® has a bare copper ground wire instead on a green THHN ground wire in the MC cable. THNN is now dual rated with THWN which allows it to be used outdoors and in conduit because it resists moisture, gas, oil and solvents.