Many people use the name Romex® when referring to type-NM cable. Romex® is a trademarked name that has come into common usage for referring to plastic-covered wires, but type-NM just means "non-metallic" and also applies to other cable styles.

This is often seen by the home inspector as the supply conduit to outside installations, such as air-conditioning compressors.

Wire types for North American wiring practices are defined by standards issued by Underwriters Laboratories, the Canadian Standards Association, the American Society for Testing and Materials, the National Electrical Manufacturers Association and the Insulated Cable Engineers Association.

Remote Distribution Panels

Although this topic is covered in other areas, because the emphasis is on safety, it's important to review.

The purpose of bonding is to ensure the electrical continuity of the fault current path, provide the capacity and ability to conduct safely any fault current likely to be imposed, and to aid in the operation of the over-current protection device.

What Is Grounding?

Generally speaking, the difference between grounding and bonding is: Grounding is a direct connection to the earth to aid in removing damaging transient over-voltages due to lightning. The purpose of bonding is to ensure the electrical continuity of the fault current path, to provide the capacity and ability to conduct safely any fault current likely to be imposed, and to aid in the operation of the over-current protection device. Properly bonding all metal parts within an electrical system helps ensure a low-impedance fault current path.

Service Drop

The service drop is the overhead service conductors located between the utility electric supply system and the service point.

The service-entrance cable SEC (blue arrow) is a line of service conductors (white arrows) located between the terminals of the service equipment (main disconnect) and a point usually outside the building, clear of building walls, where they are joined by a tap or splice (orange arrows) to the service drop or overhead service conductors (red arrows).

Valleys are weak spots in roofing systems. They have a lesser slope than the adjacent roof planes. They erode faster because water is directed into them. Inspectors must look not only at visible flashing, but also at the adjacent roof covering, at least a couple of feet on either side.