The relationship between Fuse and voltage

[hameeds01]

Hey!
I want to know that is there any relationship of FUSE with voltage.
According to my view FUSE is independent of voltage am I right?
On some Fuses it is written 5A, 125V & on some other Fuses it is written 5A, 250V.
Is there any difference in between them?

 

[dfullmer]

Re: Fuse Specification

I have wondered this myself over the years. The only real conclusion I have come to is this. As the fuse blows there is an arc as the fuse burns and melts away. A plasma for a period of time is developed. At a higher voltage for the same gap width of the arc it is likely that the arc would be maintained perhaps longer and at even higher voltages would not hold off the arc completly and defeat the idea of a fuse. So in my thinking the arc distance and creapage distance is what differs in fuse voltage ratings.

Just a though never seen it talked about anywhere.......

dfullmer

 

[shwoo]

Re: Fuse Specification

Yes, you are rigtht.
Fuse is dependent on the current flow, and it is the I^2*R that generates the
heat to melt the fuse element.
Supppose you need a fuse to block 10KV, and the fuse must have a large
gap to prevent arcing.
S. H. Woo

 

[IanP]

Re: Fuse Specification

Voltage Rating
The voltage rating of a fuse must be equal to or greater than the voltage of the circuit in which the fuse is applied. This voltage rating is the ability of the fuse to quickly extinguish the arc current after the fuse element has melted, and to prevent the system open circuit voltage from restriking across the opened fuse element. The fuse voltage rating is not a measure of its ability to withstand a specified voltage while carrying current. A fuse should never be applied where the system voltage exceeds the fuse voltage rating. However, for power systems of 600 Volts or less, fuses of a higher voltage rating can be applied on circuits of a lower system voltage. For example, a 600 Volt fuse can be used on a 208 Volt system. Standard fuse voltage ratings are 600 Volts, 300 Volts, 250 Volts, and 125 Volts.

Cited from:
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Regards,
IanP