AnsweredAssumed Answered

LFMC

Question asked by Mitch Miller on Jul 7, 2016

Archives have minimal comments starting @ 1993 some history
1965 NEC 351-2 there is no references to “not used”
1968 NEC 351-2(b)(3)- Under conditions such that its temperature, with or without enclosed conductor carrying current , is above 60C (140F)

1971 NEC 351-2(b)(2)- Where any combination of ambient and/or conductor temperature will produce an operating temperature in excess of that for which the material is approved

1993 NEC 351-2(b)(2)- Where any combination of ambient and conductor temperature will produce an operating temperature in excess of that for which the material is approved

2104 NEC 350.12(2) - Where any combination of ambient and conductor temperature produces an operating temperature in excess of that for which the material is approved

So, If I get the jest of the section
LFMC @ 60 C on a ambient temp roof of 35 C with the placed on the surface (Adjustment 33 C) could not be used.
& if the adjustment was 14C > 12” above the surface then the conductor draw would be limited to 11 C. or 8# thwn = 90C @ 55A --- 11 C @ ? or 11 C/ 90 C = ? / 55 a --     ? = 6.7 amps max load on the circuit.

Is this a proper interpretation & if not please be specific.

Outcomes