Ultra Fast Fuses

[almero]

We are in a senario where we need ultra fast blowing fuses, but our suppliers only supplies us with fast blowing fuses indicating that they are ultra fast. I am urgently looking for information to identify a ultra fast blow fuse. If anybody can help me I would greatly appreciate it.
Thanks
Almero

 

[itsmoked]

Check the fuse makers web site?

 

[ScottyUK]

Bussman and Ferraz-Shawmut both make ultra-fast fuses. International rectifier used to sell them too, although they are probably one of the above brands with a different badge. Check their websites.



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If we learn from our mistakes,
I'm getting a great education!

 

[Mike2468]

If you google on i2t fuse, you will find plenty of information. I2T fuses are ultra fast so they will open when still well within a half sinewave, such as about 2msec. They are used frequently to protect devices that are SCR based such as drives, scr power controls, etc.

I2T fuses are somewhat expensive and hard to locate on a moment's notice. If your application has high inrush, the correct I2T fuse might be larger than you expect. The Bussman or Ferraz charts offer guidance in these areas.

 

[itsmoked]

Commonly called "semiconductor fuses".

 

[peetey]

Can these fuses be used to go line to load in a meter can to find phase to ground and phase to phase faults and blow the fuse before it can start the fault? Do they have these in the 200 amp range? What is the cost of these fuses? We have no good way to figure out if there is a fault to occur when we set meters. We can with our Wiggy tell if there is a load on a leg but not if there is a fault pending. I figure a fault will go to a high current value then destroy the conductor and anything else. What is the typical current on a fault and how many cycles will it go before it clears?

--peetey

 

[itsmoked]

peetey; others will have lots to say about this.

Semiconductor fuses come in sizes up to about 1,000A and 700V.

1,000A @ 500V = $360
100A @ 250V = $50

These are out of Grainger.