Hello All, just writing to get some input from others. I have a 75kVA 3 phase transformer and it is pretty loud. I looked to make sure the that the shipping bolts were out, that it was on rubber mounts, and that all the wires going in were in flex. Besides doing that I don't think that there is anything I could do except change a transformer. That would cost a bunch and it's in a room that nobody works near anyway. Is loud transformer noise a sign of an imminent failure? or Will the transformer continue to work for a long time and just be loud? Any suggestions?
I think it's not a problem with the transformer, as much as one of acoustics. Given the right conditions, the right-angled hard surfaces we tend to make our electric rooms of can actually act as an amplifier.
I'd consider placing some softer, acoustic material on three opposing sides of the area - say, the ceiling, and two adjacent walls. This might interrupt the way the sound waves can reinforce each other.
How old is it? I've seen a lot of transformers get loud as the resin hardens up over time. It's not a danger or anything, just the nature of the beast, considering that transformer is essentially a giant 75,000 Watts speaker coil, and if it gets a little room to vibrate, it will. It's a wonder they don't all hum as loud as a jet engine.
It's it's too disruptive, replacing it is about all you can do.
How old is it is the key question. Have it tested by a real testing company, they gets these calls all the time. A DAR and PI test will be key info for evaluating the condition of the insulation. They will also inspect all connections, grounding, and other things that can "Rattle" at that B flat note.
Room Acoustics affect the sound emitted from a Transformer greatly. Square shaped rooms are the worst (equal length walls on all four sides). Rectangular shaped rooms are a bit better; and rooms with one "iregular" shaped wall are best.
Hollow wall cavity, framed with steel studs, are easilly vibrated by Transformers. Dampening the walls surrounding a Transformer is an effective way to reduce the transmitted vibrations. Dampen with typical Building Insulation or Sound Battings.
Other things which add to the noise are:
* Reflective Flooring Materials - such as hard VCT, or sealed - bare Concrete floors,
* Setting a Transformer in a corner, where one side of the Transformer is less than 6 feet from one wall, and the front is also less than 6 feet from another wall,
* Non-Flexible Conduit connections to the Transformer,
* Transformers set back - to - back (one facing forward on one side of a hollow wall, another facing backwards on the opposite side of the same wall),
* Setting Transformers against, or near Concrete walls (Tilt-Up Panels),
* Not isolating the frame from floors via dampening materials,
Try re-levelling it. I'm not sure if levelling it helps, or if its the jarring of picking up and dropping the corners when you try to adjust the way it sits.
Think of it another way: How embarrassing would it be to buy a new transformer and have someone bump the old transformer while moving the new transformer into place, and have the old transformer quit buzzing? You would never get another service call without being told to take Joe, the fork lift driver to give you a hand.