[Elecraft] Need a Fuse on the K3's Power Line?

[Don Wilhelm]

Paul,

An in-line fuse close to the power source is always a good safety 
precaution.
You are protecting the wire against a fault as well as the equipment on 
the far end of that wire.
A 12 gauge wire will safely handle 25 amps - but it will not safely 
handle the full 70 amp output of your wower supply without vaporizing 
and possibly spewing molten copper all over your hamshack, and can 
present a fire possibility.

#10 wire can safely handle 40 amps, but again, not the full output of 
your 70 am supply.

I encourage you to fuse near the power supply for the wire size that you 
use for connections from that supply.

The rigrunner is a nice device allowing you to fuse the input for the 
wire size that you have connected to the supply and also fuse the branch 
circuits according to the needs of the devices being powered.

I fuse #12 wire at 25 amps and #16 at 10 amps.  #18 gets a 5 amp fuse.

73,
Don W3FPR

Fuse it according to the wire size.

On 6/13/2013 8:46 PM, PGrig wrote:
> I was just looking at my new K3's (#7489) power cable, and see that it is not protected by a fuse (although I think I saw an instruction to use an in-line fuse if I connect it to battery power).
>
> I see what looks like a 20a fuse (or breaker) on the back of my K3/100, although I believe I read that it draws 25a  continuous duty.
>
> I was thinking of connecting my radio either directly to a 70a Astron p.s. (which will also handle my 50w 2m mobile rig and a variety of other smaller loads) or through a 25a fused receptacle on a RigRunner, itself connected to the Astron.
>
> To fuse or not to fuse--that is the question, and what is peoples' experience with the RigRunner?
>
>