turn on light, bulb blows, circuit breaker trips - what caused what?

[The Crazy Swede]

Regarding th wrence on the battery terminal thing...let's say, if the melting point of the wrench (probably chromoly) is 3 times the melting point of lead, and the contact area of each battery terminal to wrench is 4 times that of the circular dimention of the wrench handle, the wrench will melt if the battery has the availability to deliver enough current to raise the chromoly above it's melting temperature.

 

[stavangerfisherman@gmail.]

circuit breaker operating on bulb failure

This is fact and not fallacy in our case. Over the last few years we have had this happen at least a dozen times and on two separate circuits./
WE have noted that is ALWAYS the back reflector type 3 inch spot lamps with the knob end pins for special bayonet fittings that blow the fuses. It is ALWAYS very cheap or GE manufacture that does this. It never happens to normal bayonet or screw bulbs.
It could be that these are the worst enemies but coupled with an extremely low cut out setting.
I do remember way back when commissioning industrial fans, we used to ensure they werent set too low and kicking out all the time.
Who is to blame the cheap bulbs or the electrical contractor.

 

[KeepItSimpleStupid]

Ignore this arc thing for a while. The filiment shorts. Try explaining blinking headlights in a car. ABout every 30 seconds. Happened to me. I'll wait.

I've seen 120 V halogens get really bright. They didn't blow becuse they were operated on 120 DC and current limited. Why? I'll wait.

 

[Mark_R]

2008 thread