SERVICE-ENTRANCE CABLE

70-233 337-4. Bends. Bends in Type SNM cable shall be so made as not to damage the cable or its covering. The radius of the inner edge shall not be less than five times the cable diameter. 337-5. Handling. Type SNM cable shall be handled in such a manner as not to damage the cable or its covering. 337-6. Fittings. Fittings for connecting Type SNM cable to enclosures or equipment shall be identified for this use. 337-7. Bonding. The wire shield shall be bonded to the frame or enclosure of the utilization equipment and to the ground bus or connection at the power supply point. This bonding shall be accomplished using fittings (Section 337-6) or by other approved bonding methods [Section 501-16(a)]. 337-8. Construction. The conductors of Type SNM cable shall be Type TFN, TFFN, THHN, or THWN in sizes No. 18 through No. 2 copper and No. 12 through No. 2 in aluminum or copper-clad aluminum. Conductor sizes shall be permitted to be mixed in individual cables. The flat overlap- I ping metal tapes shall be spiraled with a long lay. The shield wires shall have a total cross-sectional area as required by Article 250 and not less than the largest circuit conductor in the cable. The outer jacket shall be water-, oil-, flame-, corrosion-, fungus-, and sunlight-resistant, and suitable for installation in cable trays. 337-9. Marking. Type SNM cable shall have a distinctive marking on its exterior surface for its entire length indicating its type and maximum operating temperature. It shall comply with the general marking requirements of Section 310-11. Cables that are flame-retardant and have limited-smoke characteristics shall be permitted to be identified with the suffix LS. The conductors shall each be numbered for identification from each other by durable marking on two sides 180 degrees apart every 6 inches (152 mm) of length, with alternate legends inverted to facilitate reading from both sides.