Solutions Field Services

Visual inspection by Renowned Generator Specialists

Targeted visual inspection is a vital element of generator condition assessment, as many failure mechanisms can be identified in their early stages through careful observation. Components such as stator and rotor windings, insulation systems, stator cores, frames, brushgear, and sliprings often show early signs of wear or damage that, if detected promptly, can prevent costly outages and extend equipment life. The effectiveness of visual inspection depends heavily on the expertise of those conducting it. Our generator specialists—recognized leaders in the industry with extensive experience—know exactly what to look for and where to look. Their inspections are thorough and precise, and when combined with electrical testing, provide a comprehensive assessment of your generator’s condition.

On-site Diagnostic Tests

Our generator specialists draw on a full range of standard and non-standard diagnostic tests, applying their deep expertise to select and execute the most appropriate methods based on the specific condition or issue at hand—ensuring a thorough and accurate evaluation of your generator’s health. Below is a list of on-site diagnostic tests in our toolbox.

• Off-line and on-line partial discharge (PD) test (IEEE 1434)
• Visible corona on end-windings (IEEE 1799)
• Corona (TVA) probe test (IEEE 1434)
• Dissipation factor and tip-up test (IEEE 286)
• DC ramp and step test (IEEE 95)
• Insulation resistance and polarization index (IEEE 43)
• AC and DC hipot (IEEE 95, IEEE 62.2)
• Winding resistance (IEEE 62.2)
• Stator core evaluation by EL-CID (IEEE 62.2, IEEE 1719)
• Stator wedge tightness test (IEEE 62.2)
• Pole drop test (IEEE 115)
• Non-destructive testing/examination (NDT/NDE)

Stator Winding Insulation Lab

Powertech is a recognized leader in performing qualification and acceptance testing for stator bars and coils from a diverse range of OEMs and utilities. Our Stator Winding Insulation Laboratory offers independent, third-party assessments to verify the insulation quality and performance of these components. Qualification tests and services include:

• Voltage endurance test (IEEE 1043/1553)
• Thermal cycling test (IEEE 1310)
• Partial discharge (IEEE 2465)
• Dissipation factor and tip-up (IEEE 286)
• Turn-to-turn surge/impulse (IEEE 522)
• Blackout and corona scope (IEEE 1799)
• Insulation resistance/polarization index (IEEE 43)
• DC ramp and step test (IEEE 95)
• AC/DC withstand and breakdown test
• Dissection and microscopic examination
• Insulation material analysis (glass transition temperature and organic binder)

Failure Analysis

In addition to our field services, we leverage our state-of-the-art insulation lab, non-destructive testing expertise, and materials engineering knowledge to provide comprehensive failure analysis. This integrated approach allows us to get to the bottom of failures in generators and other critical components of hydroelectric utilities.