CFR /  Title 46  /  Part 111  /  Sec. 111.60-4 Minimum cable conductor size.

Each cable conductor must be 18 AWG (0.82 mm\2\) or larger except--

(a) Each power and lighting cable conductor must be 14 AWG (2.10 mm\2\) or larger; and

(b) Each thermocouple, pyrometer, or instrumentation cable conductor must be 22 AWG (0.33 mm\2\) or larger. [CGD 94-108, 61 FR 28280, June 4, 1996]