What are the equipment used for transformer testing?

Routine Tests
1.1 Insulation Resistance Test
Purpose: Verify insulation integrity between windings and ground.
Instrument: Insulation Resistance Tester 
Test Voltage:
LV Winding: 500V–1000V DC
HV Winding: 2500V–5000V DC
1.2 Transformer Turns Ratio (TTR) Test
Purpose: Validate turns ratio between primary and secondary windings.
Instrument: Transformer Turns Ratio Tester
Acceptable Deviation: ±0.5% of rated ratio
1.3 Winding Resistance Test
Purpose: Detect loose connections or winding damage.
Instrument: Micro-Ohmmeter / DC Resistance Tester
Test Current: 1A–10A DC
1.4 Vector Group Test
Purpose: Confirm phase relationship and vector group.
Instrument: Phase Angle Meter + TTR Tester
1.5 No-Load Loss & Current Test
Purpose: Measure core losses at rated voltage.
Instrument: Power Analyzer + Voltmeter/Ammeter
1.6 Load Loss & Impedance Test
Purpose: Determine copper losses and impedance voltage.
Instrument: Power Analyzer + High-Voltage Source
1.7 Oil Dielectric Strength Test
Purpose: Assess insulation quality of transformer oil.
Instrument: Breakdown Voltage (BDV) Tester
Standard: New oil: ≥30 kV
1.8 Magnetic Balance Test
Purpose: Verify uniform flux distribution in 3-phase transformers.
Instrument: Multimeter + Variable Voltage Supply (Variac)
Type Tests (Sampled per Batch)
2.1 Short-Circuit Withstand Test
Purpose: Evaluate transformer's fault tolerance.
Instrument: High-Power Short-Circuit Test System
2.2 Lightning Impulse Test
Purpose: Simulate lightning strikes to assess dielectric strength.
Instrument: Impulse Voltage Generator + Oscilloscope
2.3 Temperature Rise Test
Purpose: Measure winding/oil temperature under full load.
Instrument: Thermocouples + IR Thermal Camera
Special Tests (Upon Request)
3.1 Partial Discharge Test
Purpose: Detect internal insulation defects.
Instrument: Partial Discharge Detector
3.2 Sweep Frequency Response Analysis (SFRA)
Purpose: Diagnose winding displacement or deformation.
Instrument: SFRA Analyzer
3.3 Frequency Response Analysis (FRA)
Purpose: Assess mechanical integrity of windings.
Instrument: Frequency Response Analyzer