Article 300 covers wiring that is factory installed in which of the following?

Article 300 of the National Electrical Code (NEC) provides guidelines for the installation of conductors, cables, raceways, and related wiring methods. This article primarily applies to wiring installations in general and does not specifically cover wiring that is factory installed in appliances or equipment.

In the context of refrigeration condenser units, water heaters, and air-handlers, these appliances typically come equipped with their own factory-installed wiring that adheres to the manufacturer's specifications and does not fall under the general installation guidelines set forth by Article 300. Instead, these factory-installed wirings are considered as part of the equipment and subject to different rules and standards applicable to appliances.

Therefore, the correct answer highlights that Article 300 does not apply to the wiring in the specified equipment, as this wiring is governed under different provisions and regulations. This understanding is essential for maintaining compliance with the NEC and ensuring the safety and efficiency of electrical installations when dealing with equipment and appliances.