What is the maximum allowable overcurrent protection for four 14/2 NM cables in contact with thermal insulation without maintaining spacing?

The maximum allowable overcurrent protection for four 14/2 NM cables in contact with thermal insulation, without maintaining required spacing, is 15 amperes. This is based on the National Electrical Code (NEC) guidelines which specify that if conductors are in contact with thermal insulation and do not have sufficient spacing or separation to allow for heat dissipation, the overcurrent protection must be limited to reduce the risk of overheating and potential fire hazards.

In general, 14-gauge wire is rated for a maximum current of 15 amps under normal conditions. However, the NEC emphasizes safety by further reducing this limit when the wires are subjected to conditions that could lead to excess heat, such as being in contact with insulating materials without proper air circulation. This is to ensure that the cables do not exceed their temperature rating, which could lead to insulation failure and increased fire risk.

The other options represent higher amperage ratings, which would not comply with the NEC requirements under these specific conditions of thermal insulation contact. Thus, 15 amperes is the correct choice, reflecting a conservative approach to electrical safety by accepting the limitations imposed by the presence of insulation.