I have been connected to the electric grid for only about five years.
Before that my electric power came from photo-voltaic panels and a
back-up generator. I could play my Duo-Art anytime with no risk of
surges or blackouts.

Since being connected I have had two major surge incidents when my 6,000
volt feeder line contacted a 60,000 volt transmission line due to "snow
unloading".  (This is how the local utility turns bad engineering into an
"Act of God.")  This ten-times over-voltage was enough to melt receptacle
contacts and just about anything that was plugged in at the time.  The
utility did pay for damages and corrected the power pole problem (but
when they changed poles a year later they put it back to the way it was).

My policy now is to unplug anything that is not in use whenever I leave
the house.  I have also installed a whole-house surge protector, for
whatever that is worth.  For the Duo-Art I have done the following in
hopes of protecting it during a surge:  I measured the current draw of
the motor and installed a medium-fast-acting fuse which handles just a
trifle more current.  This may involve some experimenting.  I then
connected a bunch of MOVs across the line after the fuse and before the
piano.  The hope is that the voltage-clamping action of the MOVs will
blow the fuse before anything happens.  What do the engineers of the
group think about this wishful thinking?

 [ That's exactly the right way to get the best protection with varistors:
 [ precede them with a carefully-sized fuse.  -- Robbie

I must say, however, that the safest route is to stay off the grid alto-
gether.  None of my solar-powered neighbors has had power-line related
problems.  For a solar installation, don't forget to ground the panel
mount and negative lead as protection against lightening.  "Home Power"
magazine can give much helpful information regarding this and other solar
power topics.  They have a web page (probably homepower.com).

There are some electronics that do not run well from certain inverters,
but the new "pure sine wave" high efficiency inverters will power just
about anything.  With the older "modified sine wave" (read "modified
square wave") inverters, induction motors can run a little warmer and
it is a good idea to clean, lubricate and check the insulation an your
1920 motor before running it for an extended period.  I would even add
a thermal protector if this is a permanent installation.

Spencer Chase

 [ Editors comment:
 [
 [ My employer shipped a big computer, with engineer, to a trade show
 [ in Paris.  The engineer was quite fatigued after the long flight
 [ from California, and he forgot to change the computer power wiring
 [ from 120-volts to 220-volts.  When he flipped on the main circuit-
 [ breaker something exploded within the computer console, and all the
 [ power on the floor at the convention center went off!
 [
 [ I quickly received a panic call from France: the hard-epoxy case
 [ of the varistor "surge protecter" blew apart, denting the console.
 [ (The MOV was almost as big as your fist!)  I advised the engineer to
 [ disconnect the MOV and try again, after he corrected the voltage-
 [ connection error. ... The computer was okay!!
 [
 [ The trade show electricians reported that the 100-ampere mains fuse
 [ blew out, but the MOV did it's job:  it prevented the over-voltage
 [ from reaching the computer while the fuse was still conducting the
 [ current.
 [
 [ Robbie Rhodes