Final answer:
The maximum current for a #12 THHN copper conductor at 122°F ambient temperature with six conductors in the conduit requires temperature correction and conductor derating; exact values need the NEC tables.
Step-by-step explanation:
The maximum current allowed on a #12 THHN copper conductor in an ambient temperature of 122°F with a total of six current-carrying conductors in the conduit can be determined by referring to the National Electric Code (NEC). However, without the NEC tables and the temperature correction and adjustment factors provided within, a specific number can't be accurately given in this response. Typically, the ampacity of the conductor is reduced due to higher ambient temperatures and more than three current-carrying conductors in a conduit. The initial ampacity rating for a #12 THHN copper wire is 30 amperes at 30°C (86°F), but it must be derated for the conditions described. The National Electrical Code (NEC) provides guidelines for ampacity ratings based on various factors, including conductor size, ambient temperature, and the number of current-carrying conductors in the same conduit.