bsaint
Well-known member
I forgot how to calculate the amp rating if you go above the rated voltage of a fuse. Like if its 10 amps at 250 vac, then what would it be at 280 vac?
Fuse amp rating question
- Thread starter bsaint
- Start date
rlitman
Well-known member
nehog
Well-known member
The fuse will have a maximum voltage (typically 32 or 240 are what you see, higher voltages require special fuses.)
Voltage rating of the fuse must be greater than or equal to what would become the open circuit voltage. For example, a glass tube fuse rated at 32 volts would not reliably interrupt current from a voltage of 120 or 230 V. If a 32 V fuse attempts to interrupt the 120 or 230 V source, an internal arc may result. The resulting plasma inside that glass tube fuse may continue to conduct current until current eventually so diminishes that plasma reverts to an insulating gas. Rated voltage should be larger than the maximum voltage it would have to disconnect. Rated voltage remains same for any one fuse, even when similar fuses are connected in series. Connecting fuses in series does not increase the rated voltage of the combination (nor of any one fuse). Medium-voltage fuses rated for a few thousand volts are never used on low voltage circuits, because of their cost and because they cannot properly clear the circuit when operating at very low voltages.
(see http://en.wikipedia.org/wiki/Fuse_(electrical)#Rated_voltage)
Voltage rating of the fuse must be greater than or equal to what would become the open circuit voltage. For example, a glass tube fuse rated at 32 volts would not reliably interrupt current from a voltage of 120 or 230 V. If a 32 V fuse attempts to interrupt the 120 or 230 V source, an internal arc may result. The resulting plasma inside that glass tube fuse may continue to conduct current until current eventually so diminishes that plasma reverts to an insulating gas. Rated voltage should be larger than the maximum voltage it would have to disconnect. Rated voltage remains same for any one fuse, even when similar fuses are connected in series. Connecting fuses in series does not increase the rated voltage of the combination (nor of any one fuse). Medium-voltage fuses rated for a few thousand volts are never used on low voltage circuits, because of their cost and because they cannot properly clear the circuit when operating at very low voltages.
(see http://en.wikipedia.org/wiki/Fuse_(electrical)#Rated_voltage)