2/0 AWG THHN/THWN Copper Conductor Ampacity

What is the maximum amps of current that a 2/0 AWG THHN/THWN copper conductor can carry inside a panelboard and connected to a breaker?

The maximum amps of current that a 2/0 AWG THHN/THWN copper conductor can carry inside a panelboard and connected to a breaker is:

a) 200 A
b) 225 A
c) 250 A
d) 275 A
Final answer: A

A 2/0 AWG THHN/THWN copper conductor is rated for 195 amps of continuous current under the NEC (National Electrical Code). However, with certain conditions and adjustments, it might handle up to 225 amps.

Explanation:

When a 2/0 AWG THHN/THWN copper conductor is inside a panelboard and connected to a breaker, it can carry 195 amps of current continuously under the NEC. However, if the question refers to the allowable ampacity for such a conductor under certain conditions like being part of a service or feeder in free air, and based on standard temperature ratings of insulation, it could be higher.

For instance, based on the 75°C insulation rating, a 2/0 copper wire can carry up to 175 amps, but when adjusted properly it might handle up to 225 amps, albeit with specific conditions applied. This could potentially align with option b) 225 A, but it also might require derating factors or adjustments based on the actual installation environment.