Customer:
Homer Electric Association (HEA), Alaska’s fifth rural electric cooperative, was established in 1945 and now serves 25,900 member-owners across 2,542 miles of energized line, covering 3,166 square miles on the Southern Kenai Peninsula.
One of HEA’s primary generation assets—a hydroelectric plant at Bradley Lake—can only be accessed by daily two-seat aircraft, making service, maintenance, and troubleshooting uniquely challenging.
Challenge:
For more than two years, HEA’s hydro facility had been reporting a persistent DC ground fault indicated by one of the station battery chargers. It was difficult to locate due to:
- The plant’s extreme remoteness,
- The age and configuration of the DC system, and
- Limited resources available onsite,
After exhausting internal troubleshooting efforts, HEA contacted its long-time representative, McKaig Evergreen, who escalated the issue to Eagle Eye Power Solutions for advanced diagnostics and onsite technical support.
Initial Assessment & Key Questions:
During the onsite training and consultation session, Eagle Eye instructors reviewed the system configuration and worked with HEA to reconstruct the DC system’s operating history. The following details emerged:
- Facility age: 34 years
- Battery chargers: replaced 2 years prior
- Charger type: dual SCR chargers
- Charger location: both feeding the same 400A DC bus
- Fault first detected: ~18–24 months earlier
- Charger output behavior: outputs did not match—one charger was showing signs of leakage, raising suspicion of an internal fault or a bus-level distribution issue
These findings indicated the likely source was not the battery string but rather a DC distribution or charger-related leakage path, requiring direct inspection of the bus.
Implementation Plan:
Review of the as-built drawings confirmed that the only way to verify the suspected issue was to:
- Wear full PPE
- Open the DC distribution cabinet
- Temporarily isolate one of the chargers
Because this required taking part of the system offline, HEA elected to wait for its next scheduled plant outage in February 2025, ensuring the diagnostic work could be performed safely without impacting operations.
Diagnostic Method:
During the outage, the HEA maintenance team used the Eagle Eye GFL-1000 Ground Fault Locator, following the procedures covered in the onsite training. The GFL-1000 allowed them to:
- Isolate the exact circuit causing the unwanted ground reference
- Trace leakage paths on the DC bus
- Compare potential fault points between the two SCR chargers
Results:
Within minutes, the HEA team positively identified the source of the two-year ground fault—something the station had been unable to locate through traditional troubleshooting and metering.
Outcome Highlights:
- Ground fault located safely during the first outage window
- Diagnostic time reduced from years to minutes
- HEA staff now trained to identify and prevent similar issues
- Confidence restored in the DC system supporting the hydro facility
Eagle Eye’s combination of onsite training, technical troubleshooting, and the GFL-1000 provided the utility with the clarity and tools needed to resolve the longstanding issue efficiently.
