Every transformer is tested prior to shipping using state-of-the-art equipment in accordance with customer specifications and the requirements of: IEEE/ANSI, CEI/IEC, CAN/CSA.

Large Power Testing Capability Features:

• Test area able to accommodate extra-large power transformers and autotransformers
• Maximum Rating: 900 MVA 3Ø and 300 MVA 1Ø
• HV Maximum Voltage: 765 kV
• Maximum BIL: 2050 kV
• Maximum Applied Potential: 500 kV 5A
• In House oil testing: DGA, Moisture, PF, DBDV, IT, Acid.

Factory Acceptance Tests

Routine Tests:

• Preliminary
• Losses
• Dielectrics
• Control wiring and CT’s
• Operation of devices

Design / other Tests:

• Temperature Rise
• Audible Sound Level
• Single Phase Excitation

Special Tests:

• Sweep Frequency Response
• Overload Test
• Overvoltage Test
• Leakage Reactance
• 1/3 Octave Band

Insulating Oil Analysis:

• Moisture content
• Neutralization Number
• Interfacial Tension
• Color
• Power Factor
• Dielectric Breakdown
• Dissolved gases in oil

Test Categories:

• Preliminary Tests
• Insulation Resistance of Windings
• Magnetic Circuit
• Insulation Power Factor and Capacitance on
• Windings
• Bushings
• Voltage-Turns Ratio
• Winding DC Resistance

Losses:

• No Load Loss
• Excitation Current
• Load Loss
• Impedance Voltage
• Zero Sequence Impedance

Dielectrics:

• Lightning Impulse
• Switching Impulse
• Applied Voltage
• Induced Voltage with Partial Discharge measurement

Standards
IEEE C.57 12 00, IEEE C.57 12 90
IEC 60076-01, IEC 60076-02, IEC 60076-03, IEC 60076-10

MEDIUM POWER TESTING CAPABILITIES

Routine tests as per IEEE C57.12.90-2015 performed on All Transformers

1. Transformation Ratio or Voltage Ratio
2. Verification of the vector group by turn ratio meter
3. Winding resistances up to 50A
4. Insulation Resistance up to 10kV Meggar
5. Insulation Resistance to Ground for Core (up to 10kV DC)
6. Capacitance and Tan delta as per Doble method up to 10kV AC Voltage
7. Lightning Impulse Withstand Test up to 550kV
8. Applied voltage tests up to 300kV
9. Short-circuit Impedance and Short-circuit losses
10. No Load Loss and No Load Current
11. Induced Voltage withstand tests
12. Partial discharge at 1.58x of Rated for 1 hour with Corona detection (Class II Transformer)
13. Control Function & wiring
14. Dissolved Gas Analysis

Special/Type/Optional Tests may be performed when requested as per IEEE C57.12.90-2015

1. Temperature Rise test
2. Overload Temperature Rise test
3. Infra-Red Thermal Image
4. Zero-Sequence Impedance on Three-Phase Transformers
5. Switching Surge Impulse Test up to 550kV class
6. Acoustic noise level
7. Harmonics of the No-Load Current
8. Sweep Frequency Response Analysis (SFRA)Doble5400
9. Oil Breakdown Voltage
10. PPM (Water Content in the oil)
11. Dew Point (only “routine” for transformers shipped without oil)

All of our plant’s keep records of all tests results, and certified test reports are provided to the customer for every transformer shipped.

WITNESS TESTING OF TRANSFORMERS

VTC welcomes hundreds of customers and consultants to our plants every year who personally witness the testing of their units. Customer rooms with wifi are available to work and relax during test transitions and employee breaks. Experienced test engineers and application engineers are available to walk customers through the plants explaining our processes and manufacturing equipment.