Gj, the transformer "repairman" told me that most transformers are extra noisy when the vibration dampers are too thin. Even if the bolts are backed off, the transformer still presses down through the thin pad and transfers some of the vibration to the enclosure. I'm still waiting to see what the final "solution" will be for the transformer we took in for him to investigate.
Thanks for the link and clarification Nick! I suppose that the quieter the transformer is, the less scary it is to put on line. The usual dry type 150 KVA transformers can sound a lot like a large arcing fault during start-up! Gives me the creaps being around them for that first energization.
