Noisy isolation transformer

[pwfarnell]

There are plenty of threads in here about the humming from Multiplus inverters, they use the dame type of toroidal transformer. A lot depends on how it is mounted, rigidly to a 4mm steel bulkhead between the engine bay and your pillow at night is a recipe for noise. Here is a link to one thread, use search to find others.

MultiPlus II - toroidal transformer humming

Dear community, I have a MultiPlus II 5000 48 in a small DESS system in our house. Located in the basement, wall-mounted, separated by a door. Under some conditions, and that’s not only high loads, humming of the toroidal transformer is very intensive. That intensive, that you can hear it even one floor above in a solid brick build house. After a few days observing, I had to take countermeasures to avoid getting in trouble with the rest of the family. It’s just too loud for an inhouse installa…