In article , wrote:

Actually, transformer cores do "wear out".

Care to elaborate?

These large capacity transformers typically last 10-30
years and fail for many reasons (other than overload).
Some of the issues:

* Ingress of air and water. This changes the dielectric
properties of the core and can, of course, lead to
corrosion problems.

* Problems related to the coolant (typically oil). The
oil can break down, there can be ionization, production
of gasses and more.

* Laminated cores can delaminate.

* Insulation can break down over time.

* The magnetic properties of the core change over time
making the transformer less efficient leading to the
production of more heat.

Often what starts out as a minor problem creates a hot
spot within the core. This deteriorates further leading
to a more catastrophic (and spectacular) failure of the
device.



--
|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~|
| Malcolm Hoar "The more I practice, the luckier I get". |
| Gary Player. |
| http://www.malch.com/ Shpx gur PQN. |
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