buffalobill wrote:
On Jan 5, 10:49 pm, Nate Nagel wrote:
Hi all,

got a real puzzler. Bought and old canister type vacuum off eBay and it
arrived today. Hooked it up, started testing it out, seemed to work
fine. Vacuumed the kitchen and dining room (tile floor) then got to an
area rug in front of the sink. Switched to the power head and it worked
OK for a minute or so and then tripped its built in circuit breaker. I
noticed when it was operating that the light bulb flickered a little
bit. Reset it, tried it again, same thing, but this time I grabbed the
(steel) wand instead of the rubber coated end of the hose and got that
unmistakeable tingle of AC. I whipped out my trusty Fluke and can't
seem to find anything in the wand, hose, etc. where either of the power
leads are shorting to steel; same thing with the body of the vacuum
itself. I even metered between both prongs of the power cord to the
vacuum case, still nothing. I *suspect* that the issue is with the
power head, but there doesn't seem to be anything amiss there that I can
identify with a meter - if nothing else, there's no way for even a short
to the case to get to the wand, as there is no possible electrical
connection between the body of the power head and the wand (the
connecting piece is plastic.) The one thing I did not do was to hook up
the power head and operate it and measure the voltage from the wand to a
known ground; I didn't want to smoke the thing completely and then have
the seller tell me that I damaged it.

I'm inclined to just box the whole thing up and send it back for a
refund, but I'm quite honestly puzzled - can anyone come up with a
reasonable explanation as to how this could happen, given what I saw
with my meter above? This is really perturbing me, usually I can come
up with a reasonable explanation as to why something failed the way it
did, but I don't get this one.

To make matters weirder, the vacuum was plugged into a GFCI protected
outlet and the GFCI didn't trip. Or can one still feel a tingle below
the threshold fault current for a typical GFCI?

nate

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replace "roosters" with "cox" to reply.http://members.cox.net/njnagel

buffalo ny: your issue can be narrowed down if you can duplicate the
problem in a different house. if you can not, the troubleshooting of
all items between your shock and the service at the pole should begin.
my mystery turned out to be a freezer leaking hot ac to electrify a
wet bx cable in the floor joists and be connecting my electrified hand
to a properly grounded metal cabinet of a different electrical device.
think outside the (electrical) box sometimes to the wiring and its
insulation.

Interesting idea, but that isn't this issue - the vacuum does not have a
grounding type plug/cord.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel