What is the main purpose of a ground fault relay?

The main purpose of a ground fault relay is to detect unintended paths to ground. These relays are essential safety devices that monitor electrical systems for ground faults, which occur when there is an unintentional connection between an energized conductor and a ground or grounded surface. When such a fault occurs, it can lead to equipment damage, increased risk of electrical shock, fire hazards, and operational disruptions.

By identifying these faults, ground fault relays protect personnel and equipment by providing timely alerts. They can initiate protective actions, such as shutting down the equipment or issuing alarms to prevent further problems. This effectiveness in spotting ground faults makes the operation of electrical systems safer and more reliable.

The other options presented do not align with the primary function of a ground fault relay. Measuring current flow is typically handled by current transformers or ammeters. Interrupting power to prevent equipment damage does occur as a secondary action but is not the relay's primary purpose. Balancing electrical loads pertains to management techniques in electrical distribution systems rather than the detection of ground faults.