Final answer:
The smallest branch circuit rating for a 20-ampere non-motor operated continuous load, based on safety regulations, is 25 amperes.
Step-by-step explanation:
The smallest branch circuit rating for a continuously loaded utilization equipment rated at 20 amperes that is non-motor operated and where the branch circuit overcurrent device is not tested for continuous loading is, per safety regulation, 25 amperes. Safety regulations limit continuous use to 80% of the breaker current capacity to allow for a safety margin and to prevent overheating which could lead to damage or fire. Therefore, for a 20-ampere continuous load, the breaker should be rated at least 25 amperes to handle the load safely.