[Amps] Fuses

[James R Carr]

Ask Bussman for their cataloge. They build current limiting fuses that will 
clear a fault of several thousand amps in less than 1/2 cycle
----- Original Message ----- 
From: "Ian White GM3SEK" <gm3sek at ifwtech.co.uk>
To: <amps at contesting.com>
Sent: Saturday, January 08, 2011 12:34 AM
Subject: Re: [Amps] Fuses


> James R Carr wrote:
>>Where pray tell do you get a hydraulic breaker? I have installed
>>several thousand over the years but have yet to see one filled with
>>oil. As for current limiting devices, the fastest breaker will hold in
>>for three to seven full cycles. To be current limiting, a fuse has to
>>clear in less
>>than 1/2 cycle.
>
> A fuse provides NO current limiting until it blows; and a breaker
> provides NO current limiting until it breaks.
>
> A lot of damage can be done in those first few milliseconds, which is
> why the fuse/breaker is only PART of the solution.
>
> We always need a surge limiting resistor in the B+ as well, to provide
> instantaneous current limiting until the fuse/breaker takes over and
> finally breaks the circuit.
>
>
> -- 
>
> 73 from Ian GM3SEK
> http://www.ifwtech.co.uk/g3sek
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