To determine the ampacity of a 6 AWG THW copper conductor in a raceway with not more than three current-carrying conductors, we will refer to the National Electrical Code (NEC) which provides specific guidelines for such scenarios.
### Step-by-step solution:
1. Identify the gauge and type of conductor:
- Conductor gauge: 6 AWG
- Insulation type: THW (Thermoplastic Heat and Water-resistant)
2. Determine the specification regarding the number of current-carrying conductors:
- The installation involves not more than three current-carrying conductors.
3. Refer to the NEC ampacity chart:
- Lookup the ampacity for a 6 AWG THW copper conductor.
- For conditions with not more than three current-carrying conductors, the National Electrical Code (NEC) specifies the ampacity values for different wire gauges and insulation types.
4. Conclusion from the lookup:
- According to the NEC, a 6 AWG THW copper conductor in a raceway with not more than three current-carrying conductors can continuously carry 55 amperes.
Therefore, the correct answer is:
b. 55 A
