46 C.F.R. § 111.60-4

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.