[R-390] R3 GFCI clarification

[w9ya at arrl.net]

Hey Joe and the gang;

> When I wrote that safety section I considered the
> situation as Perry has stated here.  We have to stop
> somewhere or we'll be re-wiring the whole house!  I
> had to assume that the house wiring was correct and up
> to date,.... not a good thing to assume as I have torn
> out some very scary wiring in houses where the owner
> should have known better!
>
> I suggest leaving it as written, the radio "should" be
> TESTED on a GFCI protected circuit, if it holds fine,
> if not then look at the filter and start
> troubleshooting from there.  That's all I was saying,
> that's what I wrote.  Reading the safety section as a

Um...not fine at all. If the (stock) filter does not trip the GFCI circuit
then you do NOT have a good ground hooked up to the radio. This is to be
considered unsafe in certain instances. i.e. It can kill you.

If you got nothing else out of the exchanges so far on this topic,
understand at least this.

AND....fix your grounding situation for sure.

Now I will go crawl back into my hole.

Vy 73;

Bob
w9ya


> whole you'll see that it was considering an unknown
> radio, that is, what to do first.  It also expects
> some knowledge of electricity and electronics, if that
> isn't there then maybe the reader should get some more
> experienced help.
>
> This radio and this entire subject isn't for the
> beginner nor is this manual to be considered a basic
> primer to the subject.
>
> No, it should have been written purposely confusing to
> someone who doesn't know the basics to encourage
> primary study elsewhere.  Like having the GFCI trip
> out and not explaning why.
>
> Leave it like it is.
>
> Joe
>
>
>
>
> --- Perry Sandeen <sandeenpa at yahoo.com> wrote:
>
>> Wrote:  OK, my biggest beef with the Y2K manual is
>> the big bold safety warning on the first couple
>> pages that says "It should also be connected to a
>> Ground Fault Circuit Interrupter.  If the radio
>> continually trips the GFCI check the line filter.".
>> The second sentence is extremely misleading
>> and potentially dangerous.<snipped>
>>
>> This is a good point well taken.  This is being
>> added to the safety section.  This was my line of
>> work for 25 years so it is learned facts, not an
>> opinion.
>>
>> Additional Safety Section
>> Here becomes the first of problems you will face.  A
>> properly grounded R390 with the originally
>> installed line filter that is perfectly functional
>> will trip the standard USA GFCI protected
>> circuit.  It does this as the filter design passes a
>> little more than 5 Ma. to ground and the GFCI
>> trip current is 4 Ma.  GFCI protected circuits are a
>> NFPA mandatory electrical code requirement in
>> new or remodeled construction for a number of years
>> now in the USA. In most areas requiring
>> electrical inspection, it is law.  If the receiver
>> is operated on 220 volts, the current leakage
>> doubles.
>>
>> You have several choices.  One is to use an
>> isolation transformer.  A second is to remove the
>> original filter.  This is not a particularly good
>> plan as the original filter provided EMI
>> protection.  The third choice, which most chose, is
>> to use a modern computer power supply filter
>> or an equivalent type low leakage filter mounted
>> inside the chassis.
>>
>> Danger: Under no circumstances should you operate
>> the  receiver without a proven good ground wire
>> attached properly to the frame GND terminal 16.
>>
>>  "Electrocution" is a bit of a misnomer that isn’t
>> self explanatory.  In most cases is actually
>> death caused by the heart rhythm being interrupted
>> by 60 cycle current.  This is called
>> ventricular fibrillation.  The heart is still
>> beating but the four chambers are not in
>> synchronization so blood is not pumped through the
>> body.  You may still be breathing more or less
>> normally.  In this process you black out and in 3 to
>> 4 minutes your brain dies due to lack of
>> oxygen.
>>
>> Depending on the moisture of your hands, the quality
>> of the alternative ground circuit, the
>> leakage through an ungrounded R390A with its
>> original filter going in one hand and out through
>> the
>> other (worst case scenario) has a very reasonable
>> chance of killing you without blowing a fuse or
>> circuit breaker.
>>
>> Danger: A variac is an adjustable auto-transformer
>> and does not provide any current leakage
>> isolation.
>>
>> Proven ground.  This is beyond scope of this manual.
>>  Check with published references such as NFPA
>> or equivalent standards.
>>
>> Regards, Perrier
>>
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