allscott
Member
- Join Date
- Jul 2004
- Posts
- 1,332
I am most definately not a PLC expert and bow to those on the site that are experts but when something intersects my area of expertise I will throw in my thoughts.
There is no "minimum" voltage rating for a fuse. A fuse has a certain resistance associated with it and will melt with a certain amount of current through it (I^2R). Voltage you will notice is not in this equation.
The voltage rating of a fuse has to do with the ability of said fuse to interupt (extinguish the arc) once the element of the fuse has melted. If the arc can not be succesfully extinguished bad things happen (explosions, fire etc......) Higher voltage fuses are longer for a reason (and sometimes filled with a dielectric material).
THE MOST IMPORTANT AND MOST OFTEN OVERLOOKED RATING OF A FUSE IS THE INTERUPTING CAPACITY OF THE FUSE (NORMALY RATED IN KaIR). When a fault occurs the amount of current available to feed it is determined by the size of the transformer ahead of it. Proper coordination of the protection in your electrical system will determine what kAir rating of fuse you will require.
If you don't know what I am talking about, find someone who does. I say this not to sound superior to anyone in this forum (I still haven't wrapped my head around indirect addressing) but I continue to see people with "programming" experience develop electrical control sytems and it worries me. Fuse holders and circuit breakers can explode (I've seen it happen) if not applied properly.
Sorry for the rant, I'm done.
There is no "minimum" voltage rating for a fuse. A fuse has a certain resistance associated with it and will melt with a certain amount of current through it (I^2R). Voltage you will notice is not in this equation.
The voltage rating of a fuse has to do with the ability of said fuse to interupt (extinguish the arc) once the element of the fuse has melted. If the arc can not be succesfully extinguished bad things happen (explosions, fire etc......) Higher voltage fuses are longer for a reason (and sometimes filled with a dielectric material).
THE MOST IMPORTANT AND MOST OFTEN OVERLOOKED RATING OF A FUSE IS THE INTERUPTING CAPACITY OF THE FUSE (NORMALY RATED IN KaIR). When a fault occurs the amount of current available to feed it is determined by the size of the transformer ahead of it. Proper coordination of the protection in your electrical system will determine what kAir rating of fuse you will require.
If you don't know what I am talking about, find someone who does. I say this not to sound superior to anyone in this forum (I still haven't wrapped my head around indirect addressing) but I continue to see people with "programming" experience develop electrical control sytems and it worries me. Fuse holders and circuit breakers can explode (I've seen it happen) if not applied properly.
Sorry for the rant, I'm done.
