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Electrical Protection for the Player Piano
By Spencer Chase

I live in a rural setting with incredibly bad electrical power
distribution.  Hopefully this will change for the better as I have
finally convinced PG&E (the electrical utility provider) to make
some obviously needed improvements to the distribution system.

We have had power surges that caused major damage to computers,
appliances, etc., so I have taken every precaution possible,
especially with the pianos.  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.

Motor rated fuses are available in a variety of sizes, chosen to
match the run and start requirements of common motors.  They have a
time-current rating that allows for starting current but also protects
the motor with the smallest fuse rating possible.  Initially I bought
all the different values available in the horsepower range of the piano
motors and used the smallest fuse that would not blow on starting.

Best regards,
Spencer Chase
Garberville, Calif.
http://www.spencerserolls.com/

 [ Spencer wrote in 1997.01.10 MMDigest: "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."  More at
 [ http://mmd.foxtail.com/archives/Digests/199701/1997.01.10.09.html
 [ -- Robbie


(Message sent Sun 15 Jan 2006, 04:33:06 GMT, from time zone GMT-0800.)

Key Words in Subject:  Electrical, Piano, Player, Protection
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