TenTec
[Top] [All Lists]

Re: [TenTec] Answer to "which is faster"...fuse or breaker...

To: tentec@contesting.com
Subject: Re: [TenTec] Answer to "which is faster"...fuse or breaker...
From: "Dr. Gerald N. Johnson" <geraldj@storm.weather.net>
Reply-to: geraldj@storm.weather.net,Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Wed, 06 Sep 2006 18:55:10 -0500
List-post: <mailto:tentec@contesting.com>
On Wed, 2006-08-30 at 10:32 -0400, john.brewer@us.schneider-electric.com
wrote:
> Due to some creative wiring while redoing the shack, I tested (inadvertently) 
> the "which is
> faster, fuse or breaker" question....twice.
> 
> This particular bench has a Astron 20A supply fed into a TenTec breaker (I 
> forget the number,
> but the one spec'd for an Omni VI).  On the downside of the breaker is a 
> small terminal strip
> branch, for small accessories (keyers,  LED lighting, etc.) which is fused at 
> 3A.
> 
> I inadvertently shorted the 3A strip (twice!) and the breaker opened twice, 
> protecting the gear
> AND the 3 amp fuse installed in the low-current 12V branch.
> 
> Those magnetic breakers are fast and reliable. They open  up fast enough to 
> protect a 3A  3AG
> fuse from the available current of a crowbarred 20A supply.
> 
> John
> 
The crowbar has no effect on the short circuit capability of the power
supply. It only comes into effect when the output voltage rises beyond a
reasonable level, probably about 15 volts. Then the crowbar circuit
drops a crowbar across the supply and shuts it down rapidly letting the
supply's internal current protection protect the rectifiers and
transformer.
-- 
73, Jerry, K0CQ,
All content copyright Dr. Gerald N. Johnson, electrical engineer

_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec

<Prev in Thread] Current Thread [Next in Thread>
  • Re: [TenTec] Answer to "which is faster"...fuse or breaker..., Dr. Gerald N. Johnson <=