[Johnson] ranger fuse

[Gary Schafer]

Fusing both legs is ok but may be a hazard when someone goes to work on the
equipment. A blown fuse on most all equipment means power is dead to the
whole thing. If the neutral fuse blows that leaves the hot leg still
energized throughout the equipment that an unsuspecting trouble shooter may
not realize. It can also leave the chassis hot if there is any short or
leakage to ground from the hot side.

You might think that the green ground wire will protect against a hot
chassis and in most cases it will. 

But consider that if the outlet power is so questionable that you are
worried about the possibility of a reversed polarity outlet (the only reason
to have a second fuse in the neutral lead) that the ground circuit to the
outlet might not be proper either. If the ground is not proper the neutral
fuse could be your demise. 

Fusing only the hot lead is safer just from the standpoint that it is common
practice.

73
Gary  K4FMX


> -----Original Message-----
> From: johnson-bounces at mailman.qth.net [mailto:johnson-
> bounces at mailman.qth.net] On Behalf Of w5htw
> Sent: Friday, February 17, 2006 10:55 AM
> To: johnson at mailman.qth.net
> Subject: Re: [Johnson] ranger fuse
> 
> Thank about it.  Using a three-wire cord, with the 'green' direct to
> chassis, and a fuse in each leg,  it doesn't matter what goes wrong.
> Reversed polarity, shorted bypass capacitor, (if after the fuse, as it
> should be)  bad wiring in the house.  It doesn't matter.  The chassis
> cannot get "hot" (unless you put a 40 amp fuse in there!.)  If the
> transformer primary shorts, the fuse blows.  There's nothing wrong with
> fusing the neutral, and I advise to do it.  Reversed polarity somewhere
> - and you don't know what some electricial did in your fuse box or wall
> outlet years ago, especially in an older home - will not be unsafe, and
> won't matter to the operation of the radio.  It will still work, it
> won't be "hot" and if anything goes wrong, a fuse blows.   I can't
> imagine NOT fusing both sides of the line, using a three-wire cord with
> hard-grounded GROUND.
> 
> There is one caveat, though.  That ground, that green wire, MUST go to a
> real ground.  That can be your ground prong on the wall outlet,
> certainly, IF that prong is really ground.  Easy to check.  Or it can be
> a solid earth ground, good strap to a rod deep into the ground outside
> your window.  Or both (though there is some fear of creating ground
> loops for RF if you do both, but it can be done.)
> 
> Go for it.  Fuse both sides of the AC line, but make SURE that ground is
> really ground.
> 
> Ed, W5HTW
> 
> >
> >
> 
> 
> 
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