Unground

Unground is a term used to describe the act or state of being without a ground connection. As a verb, unground means to remove a ground connection from equipment or a circuit. As an adjective (ungrounded), it describes devices or systems that are not connected to earth or a defined reference potential. In electrical engineering, a system can be described as ungrounded or floating when there is no direct earth path for fault currents; this contrasts with a grounded system that uses protective earth conductors and fault-clearing paths.

In practical terms, ungrounded outlets or circuits are common in older buildings or in specific industrial contexts. A device connected to an ungrounded outlet lacks a protective earth, so the risk of electric shock from metal housings can be higher if insulation fails. Some equipment is designed to be double-insulated or uses isolation to avoid the need for a ground. Modern electrical codes typically require grounding or the use of ground-fault circuit interrupters (GFCIs) in many areas to reduce shock hazards.

In power systems, ungrounded or floating neutrals are used in certain distribution schemes and in aircraft or shipboard electrical systems, where an earth fault may be less disruptive to operation. Fault detection and protection in such configurations require different strategies. Relative to grounded systems, ungrounded configurations have both advantages and drawbacks: they may reduce the severity of a single-point fault but complicate insulation monitoring and fault isolation.