1. Routine Tests (Standard for Every Transformer)

Insulation Resistance Test (Megger Test): Checks the insulation resistance between windings and between windings and the ground.

Turns Ratio Test (TTR Test): Ensures the correct ratio between primary and secondary windings.

Polarity and Phase Relationship Test: Ensures the correct phase sequence and polarity.

Winding Resistance Test: Measures the resistance of transformer windings using a DC current to detect loose connections or damage.

No-Load Loss and Current Test: Measures core losses when the transformer operates without a load.

Load Loss and Impedance Voltage Test: Determines copper losses in the windings under load conditions.

2. Type Tests (For New or Modified Transformers)

Temperature Rise Test: Evaluates how the transformer heats up under load to ensure proper cooling and thermal stability.

Lightning Impulse Test: Simulates high-voltage lightning surges to check insulation performance.

Short-Circuit Test: Determines how the transformer withstands short-circuit conditions.

3. Special Tests (For Performance & Reliability)

Dielectric Tests (High Voltage Test): Assesses the insulation system’s ability to withstand voltage surges.

Partial Discharge Test: Detects insulation deterioration by measuring partial discharges in the transformer.

Sweep Frequency Response Analysis (SFRA): Checks the mechanical integrity of transformer windings.

Dissolved Gas Analysis (DGA): Monitors gases in transformer oil to detect faults before failure.