Is It Safe to Cycle a De-Energized Tap Changer?

Electrical Testing Talk Apparatus Testing
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Is it safe to cycle an LTC on a de-energized xfmr with the oil drained from the tank? What about testing u.der those conditions?

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It is generally safe to cycle the LTC with the oil drained. This is how you perform an internal mechanical inspection. You can run certain tests under these conditions, usually low-current DLRO or other small measurements, not HV insulation testing as this would require the oil. Here are some videos of a LTC operation:

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You are fine cycling the DETC(LTC) tap changer with the oil drained. We build and rebuild Transformers here and after rewires and such Ill test to verify connectivity and resistance. Just no high power tests and certain tests such as, Power Factor, Insulation Resistance. You can still run TTR, Winding Resistance(stick to low amps) but there will be no oil temp correction needed since its empty.

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