Arcing Under Magnetic Field

External magnetic fields and the arc field itself will induce a force on the arc plasma column. The effect has been known for a long time and is quite useful in many modern applications.

Here is one old example.

www.shermco.com/100_breaker.pdf

Google searches on "magnetic arc blowout" or similar terms should get you the information you seek.

Thank you very much for giving me this link. I am aware of Fleming's left hand, right hand rules, Lorentz's force etc etc. From Google I got tons of information on electron motion in a magnetic field etc etc.

Something is cooking up in my mind - as I felt that such a well known phenomena for over a century has not been implemented in a particular area - that has puzzled me a bit WHY- I wish I knew the answer. ("Let your imagination drive your vision." -- Susan Clampitt"

Hence this posting. The reference you have given is certainly interesting - using magnetic field to quench the arc fast However it is a DC Circuit breaker. What about AC (50 & 60 Hz) breakers- is it allowed to die down in 8 to 10 msec? Has the world come up with nay other better alternative today?

Thank you.

Hi,

"What about AC (50 & 60 Hz) breakers- is it allowed to die down in 8 to 10 msec?"

This is too simplified to be answered with yes or no:

1. The source of the arc has an inductance: fast switch-off will retrigger an arc by Lenz' law.

2. The air (or other material) where the arc has burned is hot and partially ionised. This will help to reestablish the arc.

To combat the inductance you will need a sparc-gap voltage-limiter that will fire and absorb te energy from the inductance. Or an active short-circuit. (This is established in power-supplies from Advanced Energy - used for Plasma applications.)

To combat the effects of heat you need a strong blow for cooling and renewal of material.

These two effects limit the switch-off time. The ions in a plasma have a much shorter lifetime. (There are ample electrons to neutralise the ions again - generating heat with maybe problems).

RHABE