MEGA MC Cable Installation & Application Guide - Southwire

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When designing applications with paralleled Type MC cables, the equipment grounding conductor
size should be specified large enough to meet the requirements of NEC ® 250.122. see neC ® table t
250.122 Minimum size equipment grounding Conductors for grounding Raceway and
equipment on page 4. Southwire has special constructions available to meet these requirements
for high ampacity paralleled circuits.
NOTE: An external equipment ground cannot be used for paralleled circuits using MC cables.
• MC Cable RepaiR
Proper working practices will minimize installation damage to MC cable. When cable damage does
occur, replacement is recommended. When replacing the cable is not an option, follow the suggestions
below for repair.
(1) Examine the cable to ensure the conductors under the armor have not been damaged
(2) It’s best to obtain approvals for repairs on MC cable before making the repair. Inform
the authority with jurisdiction and the owner’s representative of the need for repair.
(3) Obtain repair kits and materials from distributors who service industrial accounts
(4) Follow the manufacturer’s instructions provided with the repair materials.
When repairing jacketed cable:
(1) Before the repair, protect the damaged cable against the ingress of water.
(2) Make the repair watertight. Use a shrinkable covering or electrical tape.
Always maintain or re-establish the electrical continuity and physical protection afforded by the armor prior to
the damage. To re-establish the electrical continuity of the armor, use bonding straps with constant tension
springs. Provide mechanical protection for the underlying conductors.
• neC ® CoMplianCe
neC ® uses permitted—NEC ® Section 330.10 allows MC cable in indoor and outdoor applications
including: exposed or concealed services, feeders and branch circuits, power, lighting, control and
signal circuits. When properly jacketed and listed, MC can be used in wet or dry locations, direct
buried, embedded in concrete, installed in cable trays and raceways, and hung from a messenger as
aerial cable. MC is also permitted in many hazardous location applications.
The list of permitted uses in Section 330.10 is not all-inclusive. The code language is intended to provide
guidance on where and how the cable may be used. see neC ® 330.10 uses permitted page 23.
neC ® uses not permitted—Section 330.12 of the NEC ® specifies uses of Type MC that are not
permitted. As with permitted uses, this list is not all-inclusive. In particular, note that the introductory
sentence contains the phrase, “unless the metallic sheath is suitable for the conditions or is protected
by material suitable for the conditions.” This is the clause that allows jacketed MC to be used in
direct burial, embedded in concrete, and in corrosive environments. Type MC cable used in these
applications will typically have a nonmetallic covering, such as a PVC jacket, over the metallic armor.
see neC ® 300.12 uses not permitted page 23.
Southwire MC inStallation Guide section 3. Mc cAble ApplicAtion And desiGn GUide