Q. What are the NEC rules for sizing transformer secondary conductors?
A. A set of conductors supplying single or separate loads is permitted to be connected to a transformer secondary without overcurrent protection in accordance with 240.21(C)(1) through (6). Note: The permission of the “next size up” protection rule when the conductor ampacity doesn’t correspond with the standard size overcurrent protection device of 240.4(B) doesn’t apply t