Transformer Testing & Repair
Protecting Your Most Critical—and Costly—Assets
Transformers are the backbone of your company's power system and one of the most expensive assets. Failure leads to highly disruptive downtime, extreme replacement costs, and significant safety risk.
Untested oil contamination or overheating often leads to catastrophic failure. To solve this issue, you need Transformer Testing and Repair.
Blue Runner Switchgear provides specialized diagnostics and hands-on repair to predict problems, significantly reducing the risk of fire, outages, and catastrophic failure. By doing transformer preventative maintenance, you are making the responsible choice, reducing your costs and risks. Make sure your business is in order by requesting a diagnostic and repair consultation.
When to Implement Electrical Transformer Testing & Repair
Regular, NETA Certified testing is the only way to track the internal health of the transformer and maximize its lifespan. The best way to know when you need it is
- Annual Maintenance Cycles: Recommended for all mission-critical dry and oil-filled transformers to monitor health trends.
- Suspected Issues: Anytime overheating, oil contamination, unusual noise, or tripping is suspected.
- Compliance & Insurance: Required for routine regulatory audits and often mandated by property insurance carriers to maintain coverage.
Advanced Transformer Liquid Analysis Services
Oil provides both cooling and insulation, making its condition the primary indicator of internal health and thermal stress. Therefore, having an advanced transformer liquid analysis is the first line of defense in transformer testing services. With this service, we also provide:
Dissolved Gas Analysis (DGA):
By detecting internal faults, such as overheating, arcing, or partial discharge, DGA is a critical test that analyzes gases in the oil before they become catastrophic. During this test, the key gases analyzed include hydrogen, methane, ethane, ethylene, and acetylene.
Karl Fischer Water Testing:
Measures moisture content (water-in-oil, typically in parts per million - ppm). Moisture severely degrades insulating capability by lowering the dielectric strength and accelerates the aging of the solid insulation. High moisture content significantly increases the risk of bubble formation and flashover under high-temperature or high-stress conditions.
Dielectric Testing:
Measures the oil's ability to resist electrical stress (its insulating strength), quantified by the voltage at which a spark jumps across a specified gap in the oil. Low dielectric strength indicates contamination (e.g., moisture, conducting particles) or severe degradation, meaning the oil is less effective in preventing internal arcing and short circuits.
Neutralization Number:
Indicates the acid content in the oil, typically expressed as milligrams of KOH per gram of oil (mg KOH/g). A rising acid number is a sign of oil degradation (oxidation) and is a precursor to sludge formation. Sludge is highly detrimental as it coats the windings, impedes oil circulation, and drastically reduces the transformer's cooling efficiency.
Power Factor & Furan Analysis: These two tests together measure the overall condition of the entire insulation system (liquid and solid).
- Oil Power Factor (or Dissipation Factor): Measures the dielectric losses in the oil. A high-power factor indicates contamination or polar degradation byproducts, suggesting the oil is becoming a less efficient insulator and heating up under voltage stress.
- Furan Analysis (or Furanic Compounds Test):
This is the primary indicator of the aging of solid insulation. When cellulose paper insulation breaks down due to heat and time, it produces furanic compounds, such as 2-furfural (2-FAL), which dissolve in the oil. Measuring the concentration of these compounds allows technicians to approximate the Remaining Life of the paper insulation, which is crucial since the paper cannot be easily replaced.
Certified Electrical Testing and Power Transformer Testing & Repair
Diagnostics must be paired with hands-on testing and repair to ensure mechanical integrity. Therefore, we provide these additional services that help with electrical tests and maintenance:
Turns Ratio Testing:
To confirm that the transformer is wired correctly and detecting internal problems, such as shorted turns, open circuits, or incorrect tap changer positioning, this test compares the number of turns between the primary and secondary windings. This test uses an AC voltage source to compare the voltage ratio with the nameplate value. Significant deviations indicate core or winding failure.
Insulation Resistance Testing:
Measures the integrity and overall condition of the insulation system (winding-to-ground and winding-to-winding) by applying a high DC voltage. The resulting resistance value, measured in megohms, helps predict potential winding failure, identify severe moisture ingress, or pinpoint contamination before it leads to breakdown.
Winding Resistance Measurement:
Used to check for loose connections, high resistance at terminals or splices, or broken strands in the windings. This service is a highly sensitive DC resistance measurement. When you have unacceptable resistance imbalances between phases, it can indicate thermal stresses, faulty connections, or issues within the tap changer.
Preventative Maintenance
Leak Repair and Dehydration/Degassing
On-site services are critical for maintaining the dielectric strength of the insulating oil.
- Leak Repair: Mitigates oil loss, prevents ingress of moisture and oxygen, and avoids environmental contamination.
- Dehydration/Degassing: During a specialized process, it discards moisture (dehydration) and harmful dissolved gases (degassing) from the oil. These processes are essential for restoring the oil's insulating and cooling properties, especially after prolonged exposure or fault conditions.
Tap Changer Maintenance
Essential mechanical maintenance and electrical testing of the tap changing mechanism to ensure proper voltage regulation, including checking mechanical alignment, inspecting contacts for wear or carbon buildup, and replacing or conditioning oil in the LTC compartment, as it often degrades faster due to switching arcs.
Field Inspections
Involving visual and mechanical inspection of critical external components, a vital, non-invasive component of preventative maintenance occurs, including:
- Bushings: Checking for cracks, oil leaks, or contamination.
- Cooling System: Verifying the proper function of fans, pumps, and radiators.
- Gauges: Confirming correct readings for oil level, temperature, and pressure.
- Grounding Systems: Ensuring the integrity of the grounding connections for safety and fault protection.
Transformer Testing & Repair Deliverables from Your Power Transformer Repair Company
When you work with our team at Blue Runner Switchgear, we provide NETA-certified reports that include detailed information, raw results, and expert interpretations. Logs and data, required for regulatory bodies and insurance audits, are included with our compliance documentation. Following that, we provide actionable recommendations that include clear, prioritized steps for repair, replacement, or continued monitoring.
Our team offers on-site maintenance, allowing us to perform necessary power transformer repair. Blue Runner Switchgear offers specialized, NETA-certified Electrical Transformer Maintenance Services nationwide from our central base. We protect your highest-value assets.
Schedule your transformer diagnostics today.
