[ Spencer Chase wrote in 060115 MMDigest:
> Each piano has a "motor rated" fuse, with a MOV (metal oxide
> varistor) connected between all legs of the hot, neutral and ground
> lines on either side of the fuse.  The idea is to interrupt the fuse
> when the voltage goes high and also absorb as much of the high
> voltage surge as possible.

The fuse probably won't do you a lot of good because it won't act
quickly enough, but it's a reasonable precaution anyway.  Check those
MOV's and make sure that they don't heat up.  Also, check them
occasionally to make sure they're actually still there: sometimes
they'll quietly do their job and die in the process, leaving you with
two wires and a bit of powder.

If you can find something suitable, get a whole-house surge protector.
This usually takes the form of a main breaker with extra stuff on it,
though the one I have from Erico mounts on the side of the breaker box.

If you're really concerned, you can run your most sensitive equipment
from an uninterruptible power supply, a.k.a. UPS.  These devices will,
in effect, power your equipment from a big old battery.  The battery is
kept continually charged by a separate circuit from your home's power
line.  But if something strange happens to that power line, the damage
will occur to the UPS, not the device it is powering.

I don't think that a player piano motor is big enough or sensitive
enough that it couldn't be run by a standard computer UPS, but I'm not
altogether sure of this.

In general, the rules for power surges -- lightning and other
over-voltages -- are (1) Keep your files backed up, (2) Keep your fire
insurance paid up.

Mark Kinsler