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Wed 12 Oct, 2005 05:00 pm
Two days ago at my high school we had a fire alarm. It turned out to be because an electric motor or fan burned out, and put off smoke, so someone hit the fire alarm. When everyone came back inside afterwards, about 5 classrooms had free-standing, battery-powered clocks(the old-fashioned kind, not digital) were going extremely fast(the second hand would make a revolution once about every 5-10 seconds). Also, some clocks in the janitors office had stopped working completely. There are about 100 classrooms in the school. On a map of the school, the classrooms affected seem to be in a line, though they are not next to each other. Also, 2 of the rooms affected were in portables, not one of the main buildings of the school. My teacher says that the clocks all stopped at the same time, exactly an hour before they caught back up to the actual time, meaning they had gone either 11 or 23 hours ahead.
*This actually happened, and none of the teachers know why, so I don't know if anyone will be able to answer it. One offered extra credit for a reasonable answer with reasonable proof.
Wow that's crazy. I think voodoo is the only reasonable explanation. Or maybe someone in the future was trying to travel back in time and something went horribly awry.
upsrick,
I suspect that the fan motor that burned out was a 440v 3 phase motor.
When it burned out then the 120v single phase current for the clocks was transformed into three phase (voltage unknown), a fortituous set of circumstances occurred that allowed the clocks to run fast. Theoretically they would run three times as fast (due to the phase change) but with probable voltage changes they would be unpredictable.
A practicing industrial electrician could probably supply complete details but occasionally lightning striking a supply transformer changing 440v to 120v or 240v (or vice versa) ruins a few motors in our local paper mills.
Proof would be if----
1- The motor was indeed 440v (rather common in industrial applications)
2- The clocks were supplied by one leg of the 440. (Shouldn't be done that way but occasionally accidentally is)
3- Two coils of the motor were shorted probably through a resistance to ground or possibly to the third coil on the motor.
I find most voodoo is simply undetected physics or mechanics, working on overly active human imaginations. :wink:
PS,
You may have noticed that I doubt that the clocks were free standing. I have never been in a school where each room had its own time. There is probably a master clock somewhere as the disorder that would ensue with a few minutes error would rapidly result in a huge disiplinary problem.
(pre atomic clock days
)
I've seen this in Australia 3 times over 20 years! It's wierd to see, sometimes a reset fixes this.
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