Transformer Testing with H0-X0 Link

I am curious is how what tests you can perform on this padmount transformer, since H0-X0 is linked.

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Testing of transformer is limited if Pri and Sec winding are interconnected. Usually, the manufacturer of the transformer installed a manhole on the top cover wherein you could access the connection of the link (removable)- 2 to 3 inches below the oil level. Some uses ground strap on Xo bushing for isolation of Sec to Pri Winding -internally grounded.

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Recently had this issue and contacted Doble for Power Factor and this is there response:

Basically use 2-winding template with note describing the winding having common neutral and only one test line #1 in Overall test plan can be performed with reduced test voltage to 0.5kV.

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You can perform Winding Resistance, Demag, Transformer Turns Ratio, Excitation Current, but for Power Factor the only test you can perform with a bonded HO XO is a GST-gR (grounded specimen test guarding out the red measuring lead). If you want to run a full Power Factor you will need to unlink the H0/X0 coupling.

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