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Mr. Luddite

On 11/19/2014 3:01 AM, wrote:
On Tue, 18 Nov 2014 23:58:02 -0500, "Mr. Luddite"
wrote:

On 11/18/2014 10:41 PM, wrote:
On Tue, 18 Nov 2014 21:24:49 -0500, "Mr. Luddite"
wrote:

On 11/18/2014 8:28 PM, wrote:
On Tue, 18 Nov 2014 19:57:53 -0500, F*O*A*D wrote:

Ahh...libertarianism...no regs because tainted food makes you strong.

That is the problem with you Harry. You can't see the difference
between reasonable regulation and oppressive regulation that only a
corporate compliance department can deal with.
You complain about Walmart running the Mom and Pop operations out of
business but you won't admit, over regulation is part of the problem.
The fact remains that a 200,000 square foot Walmart has just about the
same regulatory burden as a 200 square foot fruit stand. Who do you
think can absorb it easier?

I don't believe that.

The elements are still pretty much the same, Walmart just has more of
each item.
If you have a compliance department that knows all the rules, it is
just a process that you have done 100 times. When you are learning by
"citation and fine" it is not as intuitive.
In my wife's club, the municipality changed (same dirt, different
government) and the new life safety officer read the code different
than it had been interpreted for the last 25 years.
In real life, he was right and the previous guys were not keeping up.
There wasn't one single compliant business or club in the city of
Bonita for almost a year. Some just closed.

These codes change every 3 years. (another pet peeve of mine)
Because of bureaucratic inertia, by the time a code cycle is adopted,
a newer version is already out.
The problem with commercial codes is there is very little grand
fathering. The rule changes, you have to comply.
ADA is the worst and sometimes makes the least sense.

I am not an electrician but having some knowledge of electrical issues
it seems to me that some of the NFPA codes are getting a little carried
away. I can certainly understand the purpose of ground fault sensors,
especially on outdoor services but from what my son-in-law tells me
(he's a working, state licensed electrician) arc detection sensors and
other circuit protection are now required as well.

The AFCI boondoggle even has most inspectors disgusted NFPA has been
taken over by the big suppliers and it was Cuttler Hammer that rammed
the AFCI down our throats. Unfortunately the swing votes were NEMA and
the IBEW members.

This was actually written in the code in 1999 before C/H even had a
commercially viable model so it was a deferred requirement until 2002
in the 99 code and it was only going to be for the bedroom. The
problem was they never actually had any but when the 2002 cycle rolled
around they had already expanded the places they had to be used. The
product that was rushed into production really did not even work and
when it did it fell far short of the promise. It could find a shorting
arc but it couldn;t see a broken wire arc (the justification they used
in 1999) Each cycle after that saw increasing numbers of places where
they have to be used and some of the promised devices with the
capabilities they promised are just coming into the supply stream.
There have already been recalls from Square D but some of us think all
of the early version AFCIs should be recalled. That would probably put
the manufacturers out of business tho if they also had to cover the
labor. Millions of people have AFCIs that do not offer the protection
people think they have and they nuisance tripped so badly, a lot were
simply thrown away with regular breakers going in.
,

I discovered a while ago that ground fault protectors don't work well
with some inverter/battery chargers that use switching power supplies.
When they turn on the first half cycle fakes the ground fault out
causing it to trip. The first RV we had did this and it took me quite a
while to discover the problem. It worked fine on a circuit with no
ground fault detector but when plugged into a protected circuit it
tripped the ground fault every time.

The usual reason GFCIs trip is because you have a leak to ground and
that can be on the neutral side. A lot of equipment manufacturers
assume that since neutral is "grounded" anyway that they do not have
to worry about regrounding it.
AFCIs share that same problem because they have ground fault
protection in them too (at 30ma not 5ma like a GFCI)

Generally speaking if you are tripping a GFCI, you have a problem with
the equipment.. AFCIs can trip from some of those transients, phase
shifts and other stuff GFCIs get accused of seeing but not usually
GFCIs.

The one that is an urban legend is refrigerators. The fact is, an old
fridge trips a GFCI because there are internal shorts in the
compressor most of the time. You can see it with a current probe on a
scope and I guarantee, if you cut open that freon line, you will get
burned smelling freon coming out.

I agree with all you said but switching power supplies have an
additional issue with ground fault detectors, due to their design and
how they function. Not so much with smaller battery chargers but
anything that draws significant current (like an RV or Boat
inverter/charger system) usually trips it. I've had problems with
three different RV's. Works fine on a non-GFI circuit.

Mr. Luddite

On 11/19/2014 2:17 PM, wrote:
On Wed, 19 Nov 2014 06:33:38 -0500, "Mr. Luddite"
wrote:

I agree with all you said but switching power supplies have an
additional issue with ground fault detectors, due to their design and
how they function. Not so much with smaller battery chargers but
anything that draws significant current (like an RV or Boat
inverter/charger system) usually trips it. I've had problems with
three different RV's. Works fine on a non-GFI circuit.

I know of nothing in a switcher that should trip a GFCI and I have a
couple of PCs that run just fine on the GFCIs. Current may lag voltage
but Dr Kirchoff says the current in will equal the current out at any
given instant and that is what a GFCI compares.
AFCIs are different, they actually look at current "signatures" and
those spiky switching power supplies can trick one.
I bet your charger has regrounded the neutral, probably through an RF
filter. That is usually the culprit.
Wayne has the answer, A transformer. If the noise is not an issue to
you, disconnecting the filter is always an option or just couple it to
ground through a capacitor..

Low current devices like a PC usually are not a problem although
nuisance tripping has been reported. Higher current draw devices (like
an RV inverter/charger have more issues.

There's nothing wrong with the inverter/charger or the GFI. It's a
reflected component of the high frequency power supply induced into the
power source line that confuses the GFI. Not an issue unique to my
experience. You can find discussions on it elsewhere.

Wayne's transformer recommendation works just fine. I ended up having
to use a Hughes Autoformer for the RV's in Florida because the voltage
where we were often drooped significantly during parts of the day. I
measured as low as 105 vac at times. As an experiment, I tried using
the Autoformer back up in MA on the GFI circuit and everything worked fine.

Mr. Luddite

On 11/19/2014 3:33 PM, wrote:
On Wed, 19 Nov 2014 14:52:17 -0500, "Mr. Luddite"
wrote:

On 11/19/2014 2:17 PM, wrote:
On Wed, 19 Nov 2014 06:33:38 -0500, "Mr. Luddite"
wrote:

I agree with all you said but switching power supplies have an
additional issue with ground fault detectors, due to their design and
how they function. Not so much with smaller battery chargers but
anything that draws significant current (like an RV or Boat
inverter/charger system) usually trips it. I've had problems with
three different RV's. Works fine on a non-GFI circuit.

I know of nothing in a switcher that should trip a GFCI and I have a
couple of PCs that run just fine on the GFCIs. Current may lag voltage
but Dr Kirchoff says the current in will equal the current out at any
given instant and that is what a GFCI compares.
AFCIs are different, they actually look at current "signatures" and
those spiky switching power supplies can trick one.
I bet your charger has regrounded the neutral, probably through an RF
filter. That is usually the culprit.
Wayne has the answer, A transformer. If the noise is not an issue to
you, disconnecting the filter is always an option or just couple it to
ground through a capacitor..

Low current devices like a PC usually are not a problem although
nuisance tripping has been reported. Higher current draw devices (like
an RV inverter/charger have more issues.

There's nothing wrong with the inverter/charger or the GFI. It's a
reflected component of the high frequency power supply induced into the
power source line that confuses the GFI. Not an issue unique to my
experience. You can find discussions on it elsewhere.

Wayne's transformer recommendation works just fine. I ended up having
to use a Hughes Autoformer for the RV's in Florida because the voltage
where we were often drooped significantly during parts of the day. I
measured as low as 105 vac at times. As an experiment, I tried using
the Autoformer back up in MA on the GFI circuit and everything worked fine.

You are not getting much isolation with an autotransformer. The
primary and secondary are tied together.
It still might solve the problem thought because the connection is on
one if the circuit conductors so the differential toroid in the GFCI
sees the current as being balanced
I still say if you are tripping a GFCI, it is because there is a
circuit from the line conductors and ground, usually a RF suppressor.
It will be designed to pass more if you have a higher current
switcher.
I know there is plenty of "discussion" and plenty of theories but the
guys who actually design them have the opinion I trust.

Isolation transformers are effective in quenching noise (and in some
cases arcs) that can be induced either in the supply side or by the item
being powered. Basically acts as a big choke.

Ever notice what's missing in high frequency switching power supplies?
Big, heavy, iron core transformers.

Switchers are great but they can be noisy.

Wayne.B

On Wed, 19 Nov 2014 16:49:49 -0500, wrote:

Servo systems on the ships were 400 hz and I am sure the air force
guys will jump in and talk about the power systems on their planes.
You know the difference right away when you touch it. You get a ring,
not a hum..

===

400 Hz systems on planes date back to the days of World War 2. It was
well understood that higher AC frequencies saved considerable weight
on power components like transformers and servos.

Mr. Luddite

On 11/19/2014 8:39 PM, Wayne.B wrote:
On Wed, 19 Nov 2014 16:49:49 -0500, wrote:

Servo systems on the ships were 400 hz and I am sure the air force
guys will jump in and talk about the power systems on their planes.
You know the difference right away when you touch it. You get a ring,
not a hum..

===

400 Hz systems on planes date back to the days of World War 2. It was
well understood that higher AC frequencies saved considerable weight
on power components like transformers and servos.

One thing about switch mode supplies ... there are many types and
selection is dependent on application. Like everything their design is
a compromise between performance, cost and other operating parameters.

I think many run at converted frequencies of 50khz and higher, depending
on application.

Wayne.B

On Wed, 19 Nov 2014 21:03:16 -0500, "Mr. Luddite"
wrote:

On 11/19/2014 8:39 PM, Wayne.B wrote:
On Wed, 19 Nov 2014 16:49:49 -0500, wrote:

Servo systems on the ships were 400 hz and I am sure the air force
guys will jump in and talk about the power systems on their planes.
You know the difference right away when you touch it. You get a ring,
not a hum..

===

400 Hz systems on planes date back to the days of World War 2. It was
well understood that higher AC frequencies saved considerable weight
on power components like transformers and servos.

One thing about switch mode supplies ... there are many types and
selection is dependent on application. Like everything their design is
a compromise between performance, cost and other operating parameters.

I think many run at converted frequencies of 50khz and higher, depending
on application.

===

Higher frequencies are more efficient up to a point. Radiated EFI
noise becomes a bigger issue however, although now that Loran-C is
dead, that's less of a concern on boats.

I had a heavy duty alternator on one of my old sail boats that was so
electrically noisy that I had to install a field coil disconnect
switch so that I could get an accurate Loran fix. No amount of
filtering would help.

Califbill

"Mr. Luddite" wrote:
On 11/19/2014 8:39 PM, Wayne.B wrote:
On Wed, 19 Nov 2014 16:49:49 -0500, wrote:

Servo systems on the ships were 400 hz and I am sure the air force
guys will jump in and talk about the power systems on their planes.
You know the difference right away when you touch it. You get a ring,
not a hum..

===

400 Hz systems on planes date back to the days of World War 2. It was
well understood that higher AC frequencies saved considerable weight
on power components like transformers and servos.

One thing about switch mode supplies ... there are many types and
selection is dependent on application. Like everything their design is a
compromise between performance, cost and other operating parameters.

I think many run at converted frequencies of 50khz and higher, depending on application.

At one company we had a pass transistor power supply. That POS was always
a problem in certain areas of the country. Would pass every spike on the
power line through to the output. The Rockies with lots of lightning were
always faulting the disk controller.

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