[R-390] Coming: Real In-rush Protection / > Step Start

[Drew P.]

Tisha wrote:

"Sometimes you can extend the life of a transformer by re-insulating the
core, vacuum epoxy bonding or refreshing/replacing the core supporting
materials (paraffin and waxes). If this is done (if it can be done), there
is no reason on why a transformer cannot last for another 50 years. Usually
by the time we find out that the transformer is shorted or opened up it is
too late."

It would seem that the same might be accomplished through "reflowing" potting compounds where used.  I tried just that in order to quiet the loudly humming transformer in my '67 EAC. I removed the small "chassis" and connectors from the transformer and then baked the transformer at a couple hundred degrees for a few hours.  A very small amount of tar leakage, post baking, that had not been present before baking confirmed that the tar potting had reflowed.  However, upon reassembly and retest, the transformer hummed as loudly as it had before.

Maybe my transformer is low on tar and needs topping up.

Drew