Rick Christopherson said:
Alex said:
A 110v or 230v current won't do that either. Those currents are also too 'soft'. [cool]
It isn't the voltage that does the damage; it is the current in the arc flash. Same principle as an arc welder or plasma cutter.
With the house wiring's copper having a resistance less than an ohm (1.8 ohm/1000 ft) and a supply of 120 volts, the amperage during a dead-short can exceed 200 amps for a fraction of a second. I have experienced a dead short with a high enough instantaneous amperage to trip my main 200 amp breaker before it tripped the 20 amp branch circuit breaker.
That is true, I have experienced this myself too once. Arcs with a high amperage can exist for a fraction of a second. But lets stick to this particular situation where we're not just talking about a possible arc, but also about a fast moving blade. First off, actual arcing is rare in the case of a short circuit. Most of the time there is no arcing at all because there's metal on metal contact. An arc only comes to life when it suddenly decides it wants to travel through air and the metal is close enough.
But for an arc to do damage to a metal is has to strike a spot and make that spot so hot that a structural failure at that spot becomes reality. That means it has to make it so hot that it either melts or becomes weak enough to be ripped apart by the force of the collision. But, in this particular case of a blade that's spinning with a rate of a good 5000 rpm even a fraction of a second means the electric arc is spread over an area and not just one spot. The TS55 is rated at 2000-5200 rpm which in the lower case means it makes a good 30 revolutions per second and in the higher case around 85 revolutions per second.
If you've used the standard 48 tooth this means that per second 85 x 48 = 4080 teeth pass a fixed spot. So in the rare case of an actual arc existing it has exactly 1/4080th of a second to make the metal so hot that it will somehow fail. And then take in consideration that we're not talking about standard construction steel but about especially hardened steel of the blade, superior HM steel in the teeth, and a superior weld that holds blade and teeth together, then we're talking about a minute chance on actual damage. A chance that's in the order of getting hit by plane on your way home or something exceptional like that. It does happen sometimes, but it's one of those rarities you can't take into serious consideration.