[Johnson] ranger fuse

[John Lawson]

On Thu, 16 Feb 2006, SBJohnston at aol.com wrote:

>
>> But still, one of them is in the neutral side. Why?
>
> I hesitate to get into this controversy again  -grin-   but the question of
> whether to fuse in just the hot lead or both is certainly open to debate.  I


   So - you're willing to bet your life, or the lives of others in your 
shack, on the premise that the as-installed ground bonding in your wiring 
is up-to-code, and is still 'robust' after years of time and possible 
'modifications' by persons not completely familiar with the NEC...

   And the "be sure your xmtr chassis is firmly grounded" stuff is rather 
specious, too...

   IMHO, and according to residential codes in all well-developed western 
countries, the Overcurrent Interrupting Device belongs in the "hot" lead 
of the mains supply. That's the BLACK (or Brown) wire in 120V 1ph service, 
and BOTH wires in 240V 1ph service.  In 120V, Neutral WHITE (or Blue) goes 
to the neutral bar in the distro panel, and Ground (GREEN) goes to the 
ground-bond point in the distro - and there are firm and well-documented 
reasons for this.

    Thus it is impossible for a transformer primary fault in your rig to 
blow the Neutral fuse and still leave the windings energized.  Of if a 
line-filter cap breaks down, but does not short, and the Neutral fuse is 
blown, you can have substantial currents on the chassis, even though 
nothing works.

   No one's yet touched on the operational aspects of good gounding - 
well-planned gounds and mains distribution in the shack go a long way to 
smoothing out those little RF Gremlins and odd hums, wierd SWR, etc etc. 
I'm lucky enough at KB6SCO to have a flower-bed just on the other side of 
the wall from the shack, and there's an 8' copper rod in it, with only 4' 
of #6 copper wire to a drilled and tapped bussbar behind my Stuff. 
Everything homeruns to that, and all seems Happy.


   Please recall:

    It's not 'voltage' that kills, it's the voltage DROP across the body, 
thus the CURRENT flowing in the affected organs, and especially the chest 
cavity, that is deadly.  In the case of a 'hot' ungrounded chassis, you're 
just playing Russian roulette with Georg S. Ohm.

  And he's dead, too....


   Cheers

John  KB6SCO