In what scenario would rear access be mandatory for enclosed electrical equipment?

The correct answer revolves around the need for rear access being tied specifically to the maintenance of nonelectrical parts. In scenarios where equipment has enclosed electrical components, the design sometimes requires rear access to facilitate servicing or maintaining those non-electrical elements, which could include cooling systems, structural components, or safety mechanisms housed within the enclosure.

This consideration ensures that technicians can perform required maintenance without disrupting the electrical parts of the equipment, as accessing only from the front may not allow for adequate servicing of the entire unit. Therefore, if maintenance is planned for elements that don't deal directly with electrical connections, having rear access is essential to ensure a thorough and safe procedure.

Options that mention merely the height of the space or the nature of the work (like working on electrical connections) do not encapsulate this specific requirement for maintenance. Access for installation and maintenance must take into account both electrical and non-electrical components, highlighting why the focus on nonelectrical parts in option C is pivotal in determining the need for rear access in enclosed electrical equipment.