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Player Piano Motor Case Temperature
By Paul Rumpf

Dave Krall asks about motor case temperatures.  The lowest temperature
insulation class is Class A which is rated at 105 degree C. [221 F.].
This allows a 65 degree C. temperature rise at an ambient temperature
of 40 degrees C.  It is not unusual for a motor to be too hot to touch.

Obviously, cooler running is better.  The effectiveness of cooling fans
is proportional to the cube of the speed.  For 6- or 8-pole motors
[1150 or 860 rpm], shaft mounted fan blades can be practically useless.

It is most unlikely that a split phase motor will even turn if there
is a short-circuited turn in the winding.  The local heat generated in
a short-circuited turn will rapidly progress to the shorting of the
whole winding.

Hope this helps.

Paul Rumpf
Melbourne, Australia



(Message sent Fri, 13 Sep 2013 10:39:58 +1000 , from time zone +1000.)

Key Words in Subject:  Case, Motor, Piano, Player, Temperature