In the [NEC](https://www.nfpa.org/codes-and-standards/all-codes-and-standards/list-of-codes-and-standards/detail?code=70), the use of 3-#10's as a substitute for a single #8 is not explicitly prohibited. However, there are several sections of the code that could be interpreted to prohibit this practice. 310.15(B)(7) requires that neutral conductors have an ampacity that is at least equal to the ampacity of the ungrounded conductors. 310.15(B)(8) requires that where multiple neutral conductors are used, they must be bundled together and treated as a single neutral conductor.* 250.24(A)(5) requires that the equipment grounding conductor be sized in accordance with Table 250.122. Table 250.122 requires that the equipment grounding conductor for a 3-phase, 4-wire system be sized using the ampacity of the phase conductors.Based on these sections of the code, it could be argued that the use of 3-#10's as a substitute for a single #8 is not permitted. However, there is no specific section of the code that explicitly prohibits this practice.In general, it is not recommended to use 3-#10's as a substitute for a single #8. This practice can create a safety hazard by reducing the ampacity of the neutral conductor and increasing the risk of electrical fires. Flag for review