Manholes are generally vented to relieve pressure and are designed to provide access to which components?

• A. Primary cables only
• B. Secondary cables only
• C. Street lighting circuits
• D. Primary and secondary cables

Answer: (D)

Manholes are vented and built to provide safe access to the components that make up underground distribution, specifically both the primary (high-voltage) feeders and the secondary (lower-voltage) cables. This dual access is essential because a single underground path often carries high-voltage power coming in and lower-voltage power going out to customers, with splices, terminations, and transitions between the two happening inside. The venting helps relieve any pressure or gas buildup that can occur from heat, arcing, or faults, reducing hazards for technicians working inside. Street lighting circuits may run through the system as part of the distribution network, but the primary purpose of a manhole is to provide access to both primary and secondary cables and the equipment connecting them.