A new section will require a disconnecting means for most transformers.

450.14 Disconnecting Means. For transformers other than Class 2 and Class 3, a means is required to disconnect all transformer ungrounded primary conductors. The disconnecting means must be located within sight of the transformer unless the location of the disconnect is field-marked on the transformer and the disconnect is lockable. (click here to see Fig. 17)

Analysis: Although many Code users have believed that this requirement already existed, in previous NEC editions transformers were one of the only pieces of equipment that didn’t require a disconnecting means. Although there were no documented injuries to warrant this change, it’s hard to argue that this requirement doesn’t enhance safety.