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Terry K Terry K is offline
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First recorded activity by BoatBanter: Apr 2007
Posts: 95
Default Circuit breakers/fuses in parallel

On Jun 26, 4:03 pm, Herodotus wrote:
On Thu, 26 Jun 2008 07:44:39 -0700 (PDT), Terry K

wrote:

It'll be OK. I won a bet 30 years ago amongst my peers, 20
electronics techs, did a demonstration, all that.


What tiny problem arises is with the timing. Two 10 Amp fuses in
parallel pop a little sooner than one 20 Amp.


Terry K


Hi Terry,

Will the "little sooner" be much of a problem practically?

Peter



No. Thermal effect equalize the current sharing. If one fuze carries
a little more, it gets warmer and it's resistance increases, balancing
the load.

Without hi speed photography, I cannot say they fused at exactly the
same time, but it looked close, and niether blew until it seemed a
fuse rated at the sum of all fuses must pop.

Terry K