Rotor Ground Fault Protection for Motors and Generators

Promote Safety and Uptime with Continuous Ground Fault Monitoring

ACCU 660 MW generator rotor monitoring systemAccumetrics’ Ground Fault Detection Systems provide reliable, continuous, wireless detection of insulation faults on the field windings of brushless generators and motors. Advanced ground fault measurement techniques, combined with the latest innovations in digital telemetry, detect field ground faults before a catastrophic failure occurs. This will reduce the risk of unscheduled outages and allow predictive maintenance procedures to be performed.

Electrical insulation materials on the rotor field windings of generators or synchronous motors can degrade over time, leading to field ground faults. Rotor field ground faults - also referred to as earth faults - can occur on generators and motors without warning, causing severe damage to rotors and forcing costly, extended outages. These faults occur on the rotor, making them difficult to detect, particularly on units with brushless excitation systems.

Often power plant operators assume protective relays will either shut down the machine or initiate ground fault alarms at the start of an event. In truth, many generators either have no protection installed or systems primitive in function with potentially unreliable relays. On the other hand, a modern ground fault detection system provides operators with a valuable tool for early detection of faults.

Accumetrics provides a new class of field ground detectors that were developed to meet customer needs and are installed around the globe. Accumetrics monitoring goes beyond the classical function of providing a field ground fault protective relay. These systems employ digital telemetry technology, along with sophisticated insulation resistance measurement techniques, allowing for continuous insulation fault resistance monitoring. In addition, Model AT-8000 and AT-8300 Systems provide condition based monitoring, allowing users to monitor machines for significant changes indicative of a ground fault. With Ground Fault Detection Systems from Accumetrics, plant operators can feel confident about performing maintenance during a scheduled outage when demand is low and avoid emergency shutdowns.

Whether a motor or generator is operating or at standstill, Accumetrics’ systems are continuously monitoring for faults. Operators have the assurance that a ground fault is not causing hidden damage that could lead to an unexpected and costly long-term outage.

View details on our complete line of Ground Fault Detection Systems on our  Ground Fault Protection webpage or  compare our products.