About power:  Computers and other modern electronic devices have
integrated circuits, transistors, processors and other such
semiconductor parts inside.  These parts are especially susceptible to
power spikes, surges and the like.  As such these devices do need to be
protected; particularly if you live in an area with bad power.  It only
takes a few milliseconds to turn an ultra-modern piece of equipment
into a hunk of useless junk.  This is one of the tradeoffs for the
convenience of living in our microprocessor controlled modern world.

However, back in the days of the player piano, power issues were simply
not an issue -- power was particularly "dirty" back then: dips, spikes
and surges and the occasional brief power failure (the lights
flickering off and on) were all quite normal.  Occasionally you might
notice the lights going bright to dim or blinking bright for a second
or two.  People were happy to have electric power at all.

Back in those days most of what was run on electric power was lights,
electric heaters, electric fans and perhaps a toaster.  These were all
devices that were quite tolerant of power that wasn't "pristine"; these
were devices that could easily withstand short power surges without any
damage what so ever.

Now think about it:  The electrical parts on player piano would be just
the pump motor, or on a nickelodeon perhaps a roll motor, some lights.
These are very much the same kinds of devices (although in different
forms) that you would find in an early 20th century home; these being
mostly lights, and motors (such as electric fans).

Realistically, to cause any damage to a player piano motor, it would
have to be exposed to an over voltage long enough for the motor to
overheat.  Depending of the size and length in time of the over-voltage,
damage from overheating could take anywhere from 3 or 4 minutes to over
a half an hour.  The short power glitches that you are likely to see
from modern electric power are usually in the millisecond range -- far
to fast to get anything in a player piano to burn up.

About surge protectors and MOVs: These devices are designed to absorb
over-voltage but for only a few hundred milliseconds at a time (for
about 1/10 of a second maximum).  After that the surge-protecting
device simply stops protecting and without warning.  Plugging a player
piano into a surge protector or using MOVs won't hurt anything but is
won't help either.  Being that any damage to the player piano motor
would happen in the order of minutes and the surge protector or MOV
would fry itself in order of seconds, if the player piano were to
suffer any real damage, the surge protector or MOV would have given up
long before hand.

However, one item in some player pianos that could be damaged by bad
power is the electronic speed control used in after-market vacuum pumps
(like the particle board box vacuum pump that Player Piano Co. sells).
Although the speed control is _very_ durable, electrically speaking, it
could be damaged by a power spike on the power line.

Overall modern power is _much_ better than is was at the turn of the
previous century.  If player pianos weren't in any real danger back then,
then for the most part they aren't today.

About fuses:  "Motor Rated" (or 'slow blow') fuses are a good idea.
In fact, fuses are _always_ a good idea, but the fuse is only going to
protect the motor against "catastrophic" failure such as an internal
short or long term overheating, hopefully preventing a fire.  The fuses
will do nothing to protect against short power glitches, nor are they
supposed to.

Putting MOVs on all three legs of the incoming power is a technique
that is used to protect sensitive electronic equipment, but again it
will do nothing for the motor in a player piano.  In fact player pianos
originally never had the third leg.  However, putting the MOVs _after_
the fuse may gain some protection, sometimes.  If the MOV absorbs
enough power to blow the up-stream fuse, then the player piano would be
effectively cut off.  But this assumes that the MOV is rated to absorb
a fair amount of power for the 1/2 second or so it is going to take for
the "motor rated" fuse to blow.  More than likely the MOV would fry
first.

Ray Finch
Albuquerque, New Mexico

 [ The protection scheme described by Spencer Chase in 060115 MMDigest
 [ is much the same as that recommended by Littelfuse, wherein the MOV
 [ is selected to absorb the energy surge until the fuse opens.  See
 [ http://www.littelfuse.com/data/en/Application_Notes/ec608.pdf
 [ Has anybody else installed this protection method in a player piano
 [ or orchestrion?  -- Robbie