In article , Phil Allison wrote:

"Don Klipstein"

Then again, I doubt a voltage spike lasting long enough to burn out a
transformer will be absorbed by a 1 uF cap across a 120V AC line.

** You missed the point entirely.

A voltage spike ( or a series of them) can easily cause insulation failure
in the enamel winding wire of the primary - then the energy to explode
the lead in and lead out wires comes from the 120 volt AC supply.

Is the O.P. having other things in his house blowing from voltage spikes
severe enough to blow transformer primary winding insulation?

I have seen lots of things blow from line voltage surges, but no
transformers indoors blowing when line voltage spikes blow other things.

My experience is that usual 120V-primary step-down transformers can
produce pulses of 2 kilovolts when used on pulses in reverse. In fact, I
have done that with about 8 different transformers dozens of times each,
and none of them lost their ability to do that. (I am aware of line
voltage spikes being noted to get even higher.)

There is also the issue of line voltage surges not easily being loaded
down by capacitors for whatever reason. I have experience with them
blowing things that had capacitors, including a CFL that had probably a 22
or 47 uF capacitor across the output of its internal bridge rectifier as
they usually do. No transformer failures in the same house from the same
event, though there were electronics failures.

The usual solutions to absorb line voltage spikes are MOVs and other
devices that absorb voltage surges by becoming conductive in response to
excessive voltage.

--
- Don Klipstein )