Grounding Transformers

Grounding transformers create an artificial neutral point in ungrounded three-phase power systems, enabling effective system grounding and ground fault protection. Their kVA rating is determined by the system line-to-neutral voltage, the required ground fault current, and the specified fault duration, typically ranging from a few seconds to several minutes.

During a line-to-ground fault, grounding transformers provide a controlled return path for the fault current, limiting transient overvoltages and enabling reliable operation of protective relays and circuit breakers.

Grounding transformers are designed to withstand the specified ground fault current until the protection system clears the fault. Accordingly, they are manufactured with short-time thermal ratings. Hilkar offers oil-immersed, hermetically sealed, and dry-type grounding transformers for a wide range of industrial and utility applications.