The URD component used to isolate, test, and ground is:

• A. Grounding elbow
• B. Molded underground splice
• C. Portable feed-through bushing
• D. Disconnect switch

Answer: (C)

Isolating a section of URD cable and ensuring it can be safely tested and grounded is a common maintenance task. The portable feed-through bushing is designed for this purpose. It provides an insulated, removable connection point that you can install on the end of a live feeder to create an isolated stub. With the bushing in place, you can attach a test lead to verify that the section is de-energized and, if needed, connect a temporary grounding conductor to discharge any stored energy. Its portability lets you move it along the underground run as you work.

Other URD components serve different roles: a grounding elbow provides a fixed ground connection at terminations, a molded underground splice is a joint used to connect cables, and a disconnect switch is used to open a circuit. None of these offer the same convenient combination of isolation, testing access, and grounding that the portable feed-through bushing provides.