Fuse AIC Rating

[Grouch1980]

Hi,
Quick simple question...

In the link to this Eaton fuse:
https://www.eaton.com/us/en-us/skuPage.KRP-C-800SP.html

The short circuit rating mentions 300kAIC at 600 Vac. Does this mean even at 208 or 240 volt systems, the rating is still 300kAIC as well?

 

[infinity]

I believe that the rating is any voltage up to 600 volts. If you're looking to use them on a lower voltage system they probably won't fit in the fuse gap in the switch if the switch isn't rated for 600 volts.

 

[Grouch1980]

I believe that the rating is any voltage up to 600 volts. If you're looking to use them on a lower voltage system they probably won't fit in the fuse gap in the switch.

You mean use a 600 volt rated switch instead of 240 volt rated?

 

[kwired]

You mean use a 600 volt rated switch instead of 240 volt rated?

Yes. You can use 600 volt fuse on 240 volt application.

For the most part there is no standard 480 volt fuses and we use 600 volt fuses for most 480 volt applications.

The interrupt rating of the switch must also be considered. They usually will say what the rating is with a particular fuse type if more than one type can fit.

Also remember 100kA @ 240 volts is less overall energy than @ 600 volts

 

[infinity]

You mean use a 600 volt rated switch instead of 240 volt rated?

Yes if you want the 600 volt fuse to fit in the fuse gap of the switch. With the different voltage ratings those two fuses types are not physically interchangeable.

 

[Grouch1980]

Thanks everyone.

 

[Jraef]

Thanks everyone.

You’re welcome. I contributed nothing here but you did say everyone…

Interrupt ratings generally go up as voltage goes down, because they are based on potential energy in the circuit when there is a fault. Fuses generally only give the interrupt rating for their max. rated voltage because of this issue of being more difficult to use at lower voltages. But on circuit breakers you will see the values for different voltages, that’s where you can see the ratings increase. That said, it’s unlikely that a fuse with a 300kAIC rating at 600V will have higher than that at 240V, because there would be little practical reason to test it any higher than that.

 

[Grouch1980]

You’re welcome. I contributed nothing here but you did say everyone…

Can't argue against that