Which test detects breakdown of insulators or conductors in transformer windings?

Which test detects breakdown of insulators or conductors in transformer windings?

• A. Resistance Testing
• B. Dielectric Testing
• C. Insulation Maintenance
• D. Continuity Testing

Answer: (A)

Dielectric testing is the test used to detect breakdown of insulators or conductors in transformer windings. By applying a voltage higher than normal operating levels, it checks the insulation’s ability to withstand voltage. If the insulation has weak spots, moisture, contamination, or aging, it will reveal breakdown or leakage paths under this high-voltage stress. This directly targets the integrity of the insulation between windings and to ground or between turns, which is what would fail when insulators or conductor insulation break down. Resistance testing measures winding resistance to spot issues like poor connections or shorted turns, but it doesn’t reveal insulation breakdown. Continuity testing only confirms a complete electrical path, not the insulation’s strength. Insulation maintenance isn’t a test itself.

Dielectric testing is the test used to detect breakdown of insulators or conductors in transformer windings. By applying a voltage higher than normal operating levels, it checks the insulation’s ability to withstand voltage. If the insulation has weak spots, moisture, contamination, or aging, it will reveal breakdown or leakage paths under this high-voltage stress. This directly targets the integrity of the insulation between windings and to ground or between turns, which is what would fail when insulators or conductor insulation break down.

Resistance testing measures winding resistance to spot issues like poor connections or shorted turns, but it doesn’t reveal insulation breakdown. Continuity testing only confirms a complete electrical path, not the insulation’s strength. Insulation maintenance isn’t a test itself.