Fire Hazard in Grand Players
By Craig Brougher
|Regarding the fire which John Tuttle experienced in a Lauter:
>>The Headline read, "Player piano burns but house is spared".
The incident caused by conductive neoprene tubing being used as "insulation" has probably been repeated a number of times, but I had another very close call of a different nature.
I was in a customer's home in another city, making repairs to a Duo-Art. I put on a roll and switched it on, and it began playing, but I heard a kind of "splutt" sound when the start winding of the motor kicked out. So while the piece was playing I casually drug my bones back under the piano and looked up in time to see flames licking the soundboard and flattening themselves all over the board in a one-foot area above the motor, growing hotter by the second. That was scary. I took the motor to a rewinder who rewound it and repaired the start switch.
The point is this: The start winding probably had a shorted turn, or partially shorted turn which generated too much heat and caused a high power spark from the start switch, just as soon as that switch opened. A combination of oily dirt ignited, and the high heat already in the motor super-heated the tars, which then turned it into a torch as the inductance demanded increasing current (I sq. X R) to counter the increasing resistance. The fire was totally silent and would not be heard by anyone until it was just too late.
If your grand reproducer motor runs hot to the degree that you can smell it after it has been running for 30 minutes to an hour, I suggest you drop it and take it to a small motor shop for a checkover before something like this happens to you, too. There is also a solid state replacement for the start switch, in case it has distorted or burned up over the years. And a shorted start winding will finish the start switch for you in short order.
(Message sent Sat 10 Aug 1996, 15:06:57 GMT, from time zone GMT.)