For a raceway containing 30 current carrying conductors, what percentage is the ampacity of each conductor reduced to?

When a raceway contains a large number of current-carrying conductors, the ampacity, or current-carrying capacity, of each conductor must be reduced due to the increased heat generated by the combined currents. The National Electrical Code (NEC) provides guidelines for these adjustments in ampacity.

For 30 current-carrying conductors, the NEC specifies that conductors must have their ampacity derated significantly. According to NEC guidelines, when there are more than 24 conductors installed in a raceway or cable, the ampacity of each conductor is reduced to 45%. This derating is necessary to prevent overheating and ensure safe electrical operation.

In this case, since there are exactly 30 conductors involved, this falls into the category where the appropriate derating factor is applied, leading to a conclusion that the ampacity of each conductor is reduced to 45%. This helps in maintaining system reliability and safety.