"Those of you who think you know it all, are very annoying those who do."
You know not that of which you speak.
There *is* energy in the magnetic field surrounding the inductor.
Just _where_ do you think that energy came from?
When power was applied some electricity went _into+ the device that did
_NOT_ come out as electricity *at*that*time*.
Similarly, when power is removed, some electricity comes out _after_ the
switch is opened. Just _where_ do you think that energy comes from?
hint, it is *stored* in the electromagnetic field.
Just where do you think the 'back emf' comes from when power is suddenly
removed from an inductor?
'Male bovine excrement' applies. You even stated one situation you call
'impossible'. To wit: 'A changing voltage through an inductor, may create a
phase-lagged current.' If you measure the *instantaneous* current _before_
and after the 'phase-shifting' device You *will* see different values.
Draw a sine-wave, measure the instantaneous (not 'peak', or 'mean) amplitude
at any given point during full cycle. Now measure the instantaneous amplitude
at a slightly different phase of the waveform. Unless the two points you
chose are symmetric around a maxima or minima of the waveform the
*INSTANTANEOUS* amplitude _will_ be different.
And a *transient* phase-shift within a device _can_ cause a sufficient
'instantaneous' current difference (measured on opposite sides of the
phase-shift) to trip an old-style GFCI.
"Bill" wrote in message
Eric, Doesn't it just warm your heart to see people take a thread and
make it their own! Reminds me of a guy I knew who was outstanding in
his field. ; )
==============Must have been a farmer!
I know of complete factories that are GFCI protected and most high voltage
protection systems that include 87 (IEEE) GFI protection.
They can and should be used but will find defective wiring.
"Steve Barker" wrote in message
motors will often trip GFCI's that is why they should never be used on
refrigerators, disposals, diswashers and sump pumps and the like.
remove the "not" from my address to email
Well you are absolutely wrong.
New code requires that the sump pump be plugged into a gfi.
So What do you say to that...
Any basement circuit requires it.
I had an inspection recently and they were trying to ding me on that,
but my inspection was not related to that. And I argued, that when the
house was built that was what was called for.
On 9/4/2011 11:44 PM, Steve Barker wrote:
I am not wrong in saying they should not be used on motors. It's been
proven that motors can cause false trips on gfci's.
Plus, very few AHJ's are on the "new" code. And _I_ for one will never
put a sump pump on a gfci. Code or not. And I'm not gonna look it up,
but i think you're wrong.
remove the "not" from my address to email
Only if it's in an unfinished basement (or unfinished portion of a
basement), or a crawl space. And that's not new, either: that provision
dates from the 2008 Code, maybe earlier.
I say, you're mistaken.
GFCI protection is required *only* in unfinished basements and
unfinished portions of partially finished basements:
"...receptacles ... in the locations specified ... shall have
ground-fault protection ... Unfinished basements -- for purposes of this
section, unfinished basements are defined as portions or areas of the
basement not intended as habitable rooms and limited to storage areas,
work rooms, and the like ..." [2011 NEC, Article 210.8(A)(5)]
One of two things, then: either you live in a jurisdiction that has
adopted more stringent rules than those specified by the NEC, or your
local inspector doesn't know or doesn't understand the NEC.
The NEC is only a model, a suggestion. In and of itself, it has no force
at all; it acquires the force of law *only* when it is adopted as the
governing regulation by state law or municipal ordinance -- and such
jurisdictions are free to adopt it in toto, or in part, or with such
exceptions or additions as they see fit. It's entirely possible that
your jurisdiction has done exactly that. That's not unheard of, you
know: the Chicago electrical code, as I understand it, is *based* on the
NEC, but has numerous additions (e.g. all wiring must be run in conduit,
no Romex allowed) that appear to stem as much from a desire to keep
union electricians employed as from an understandably morbid fear of
Chicago Electrical code bears only a vague resemblance to the NEC. Most
jurisdictions cite a particular year of the NEC (or of the BOMA -- Building
Owners and Managers Association -- code, which incorporates by reference
the NFPA -- National Fire Prevention Association -- code, which incorporates
the NEC by reference) as 'base', and then add any additional jurisdiction-
The Chicago building code specifications for electric wiring does *NOT*
do that. Everything is specified directly in the local code. And the
code itself is a 'swamp'. I once had a 'difference of opinion' with
a building inspector over an electrical issue, and we spent a good
five minutes citing code 'exceptions' back and forth at each other.
Chicago code does -not- say 'this section rules _unless_ the exception
in xyz applies', it says "if this condition is met, then section xyx does
not apply". Chasing the applicable exceptions to a given section is a
challenge. And the section that contains an exception to the base-line
rule, may itself be subject to an 'exception' in a far-removed section
of the code. "lather, rinse, repeat" applies.
I eventually prevailed over the electrical inspector, having reverse-
engineered the code one step further than the inspector had. And he
'went away unhappy', having _not_ collected a payoff over the purported
Chicago electrical code allows some things that are forbidden by NEC,
and forbids other things that are allowed by the NEC. There is a fair
amount of 'coincidental' overlap on the basics, but a *lot* of difference
in the 'details'.
Yup! Here come's the old "I wasn't there but this is what really happened"
and "I know more than your Inspector does"
Maybe Dougy has learned something about not telling **you** what happened
**to you** from the other side of the world.
Funniest yet... Dougy has professed to the world, repeatedly, he has
filtered me and has his mouth gagged, for once.
Stamping his feet as he bangs his head against the wall, pacing, trying not
to burst a #14cu in his head.
Hook, line, and GFI.
"tiredofspam" wrote in message
Again, tell that to my local inspector. GFCI's were required in my
finished basement. Every outlet had to be on a protected ckt.
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