Noisy Tranformer - Bad core laminations? 4

[Chapmeister]

Hey all,
I have a 300kVA Marcus brand transformer with an excessively high sound output. The sound output has been metered at ~85dB, which is well over the rated 65dB. The transformer was only purchased and install a little over 1 year ago. It was physically inspected and is clean as a whistle. Runs very cool.

Here are the tranformer specs:
Brand Marcus
Model MK300A7-13-F
Power Rating 300kVA
High Voltage 600?347V
Low Voltage 416Y240V
Impedance 3.3%
Temp. Rise 115ºC
K-Factor K13

We had some test equipment install for approx 24 hours, which showed low power factor ~0.5, and elevated current harmonics %THD consistantly over 25% (between 27.5% and 30%). What should I make of these results?? I was told it could be bad core lamination. Any advice/comments are appreciated!

 

[waross]

"I didn't think the pf on the switchgear bus and the transformer primary would be different considering they're directly connected."

Another point;
The power factor is a phase shift between the voltage and the current. If there are any other loads on the switchgear bus, then the phase angle of the switchgear current will be the vector sum of all the load currents. This current and the resulting phase angle and power factor may easily be different than the current, current phase angle and the power factor in the transformer.
respectfully