GFI and Surge Protection
James Bott
protection. Is there any reason you can't use GFI in a MH? If you can,
should I use GFI circuit breakers or outlets? I have two circuit breakers
one for the AC and one for outlets. I have 4 outlets.
Also, does anyone have any recommendations for surge protection for the
entire MH's AC?
James Bott
San Diego
Bob Hatch
news:a2pir9$r01$1...@suaar1ab.prod.compuserve.com...
locate the first plug on the circuit and put a GFI plug there. Follow
instructions on wiring closely.
HTH.
--
bobh...@go.com is a throw away
email address. I do not check for mail
there, so will not respond.
One@home.com Wade
"James Bott" <jb...@compuserve.com> wrote in message
news:a2pir9$r01$1...@suaar1ab.prod.compuserve.com...
other outlets are most likely on the same circuit anyway.
Wade
Chris Bryant
> My older '79 Jamboree 23' MH doesn't have any Ground Fault Interrupt
> (GFI) protection. Is there any reason you can't use GFI in a MH? If you
> can, should I use GFI circuit breakers or outlets? I have two circuit
> breakers one for the AC and one for outlets. I have 4 outlets.
>
I would definately use the outlets- usually the kitchen, bathroom,
refrigerator, and outside outlets are the only ones you need to worry
about. As Wade said, the GFI outlet will be on the first outlet in the
series.
The biggest problem with these is that you will (probably) have to get a
box extender, as GFI outlets are usually to deep to fit into the standard
space.
> Also, does anyone have any recommendations for surge protection for the
> entire MH's AC?
I would go to an electrical suppy house, and look for a whole house
supressor- but any of these are only as good as the ground on the power
pole.
--
Chris Bryant
Bryant RV Services
http://www.BryantRV.com
Bob Hatch
> As Wade said, the GFI outlet will be on the first outlet >in the
> series.
Chris, it was me, Bob Hatch that said that. Wade is taller than me and
drives a Triple E. I have a Winnebago. Hope this helps you in being able to
tell us apart....<g>
One@home.com Wade
"Bob Hatch" <bobh...@go.com> wrote in message
news:a2pnje$12r4ot$1...@ID-85448.news.dfncis.de...
> "Chris Bryant" <bryan...@cfl.rr.com> wrote in message
>
> > As Wade said, the GFI outlet will be on the first outlet >in the
> > series.
>
> Chris, it was me, Bob Hatch that said that. Wade is taller than me and
> drives a Triple E. I have a Winnebago. Hope this helps you in being able
to
> tell us apart....<g>
> --
seconds look at the posting time.
Wade
Bob Hatch
news:TIZ38.103179$nm3.4...@news1.rdc1.bc.home.com...
Wade: Who also posts via Berlin 10:20 AM.
Bob: Whose clock is set via Atomic Clock Software, 10:17AM
Bob, clearly the winner by 3 minutes.
One@home.com Wade
> "Wade" <No O...@Home.com> wrote in message
> news:TIZ38.103179$nm3.4...@news1.rdc1.bc.home.com...
> >
> > "Bob Hatch" <bobh...@go.com> wrote in message
> > news:a2pnje$12r4ot$1...@ID-85448.news.dfncis.de...
> > > "Chris Bryant" <bryan...@cfl.rr.com> wrote in message
> > >
> > > > As Wade said, the GFI outlet will be on the first outlet >in the
> > > > series.
> > >
> > > Chris, it was me, Bob Hatch that said that. Wade is taller than me and
> > > drives a Triple E. I have a Winnebago. Hope this helps you in being
able
> > to
> > > tell us apart....<g>
> > > --
> > All of above is true, however you forgot to mention I was also faster by
> two
> > seconds look at the posting time.
> > Wade
> >
> >
> According to the time line on my newsreader:
>
> Wade: Who also posts via Berlin 10:20 AM.
> Bob: Whose clock is set via Atomic Clock Software, 10:17AM
>
> Bob, clearly the winner by 3 minutes.
> --
your plutonium trickle.
Wade
Bob Hatch
In the start of a long and rather ridiculous thread:
> > > > "Chris Bryant" <bryan...@cfl.rr.com> wrote in message
> > > >
> > > > > As Wade said, the GFI outlet will be on the first outlet >in the
> > > > > series.
To which I then replied, wishing for accuracy:
> > > > Chris, it was me, Bob Hatch that said that. Wade is taller than me
and
> > > > drives a Triple E. I have a Winnebago. Hope this helps you in being
> able
> > > to
> > > > tell us apart....<g>
Then Wade, wishing to want to change the past in true revisionist history
wrote:
> > > All of above is true, however you forgot to mention I was also faster
by
> > two
> > > seconds look at the posting time.
> > > Wade
> > >
To which I posted this true correction:
> > According to the time line on my newsreader:
> >
> > Wade: Who also posts via Berlin 10:20 AM.
> > Bob: Whose clock is set via Atomic Clock Software, 10:17AM
> >
> > Bob, clearly the winner by 3 minutes.
Then, Wade comes back with this drivel, trying to downplay the accuracy of
the time piece at the US Naval Observatory.
> No No this cannot be, you must be overclocking by a few atoms please
adjust
> your plutonium trickle.
> Wade
>
Wade, you have to find a more precise way to set your clock on the computer
than by stepping out on the porch and looking at the sun>>>><G>
Steph and Dud B.
GFI breaker (if it fits)?
As for surge suppression, you can buy suppressors that plug into the power
cord from Camping World.
--
Dudley - http://members.aol.com/stephndudb/rv.html
"Camping" in 5000 pounds of stick and tin.
"Chris Bryant" <bryan...@cfl.rr.com> wrote in message
news:pan.2002.01.24.13...@cfl.rr.com...
Chris Bryant
<<..>>
>>
>According to the time line on my newsreader:
>
>Wade: Who also posts via Berlin 10:20 AM.
>Bob: Whose clock is set via Atomic Clock Software, 10:17AM
>
>Bob, clearly the winner by 3 minutes.
Yep- I had to go to the judges, but it appears you are
correct. The funny thing is I was using a different news reader on a
different server (road runner), and Wades post was the only one I saw
at the time- but when I went back to this server (Berlin)- *your* post
was the only one I saw.
I think my new Tachyon generator might have something to do
with it.
--
Chris Bryant
Bryant RV Services- http://www.bryantrv.com
Chris Bryant
>Due to the box size restriction, would he be better off just putting in a
>GFI breaker (if it fits)?
>As for surge suppression, you can buy suppressors that plug into the power
>cord from Camping World.
The only thing I have against the breakers is cost- $30-50 as
opposed to $5-7, but the time saved in installation might well make up
for that.
Cost is also what I have against the typical RV surge
suppressor- they take $10 worth of parts and charge close to $100 for
them.
--
Chris Bryant
Bryant RV Services- http://www.bryantrv.com
Jim Redelfs
"James Bott" <jb...@compuserve.com> wrote:
I purchased and use the following device that provides surge and GFCI
protection to the entire RV. This would certainly be EASIER than wiring
and rewiring the on-board stuff.
<http://www.campingworld.com/browse/skus/index.cfm?skunum=18337&src=SRCH&
tcode=37>
:)
JR
bill horne
> I think my new Tachyon generator might have something to do
> with it.
> --
> Chris Bryant
> Bryant RV Services- http://www.bryantrv.com
Yeah, you'd better turn that damned thing off before you end up
someplace where all things are possible. That might turn out to be a
quasar up your keister or boson up your black hole.
--
bill
Theory don't mean squat if it don't work.
Marc Alan
"James Bott" <jb...@compuserve.com> wrote in message
news:a2pir9$r01$1...@suaar1ab.prod.compuserve.com...
GFI's require a ground to actually work. Your RV may only have a ground when
you are connected to shore power. I don't know about you, but I have
rubber-like tires on my RV that are on the ground, that makes the RV pretty
well insulated from the ground, hence no ground!
As I recall, in many of the older RV's, there is only two-wire romex between
AC receptacles (hence no actual ground). I don't know if the '79 jamboree
has two or three wire, but I've been pretty sucessful at opening an AC
receptacle and seeing if two or three wires go to the plug (The plug may
have three holes, but some only have two wires to it!).
Since most Surge supreesors shunt to ground when a surge happens, not having
a ground makes them useless.
I solved the problem of grounding/electrical equipment by running a seperate
extension cord to the sites power box which has all three wires connected
and plugging my GFI and surge suppressor into that.
Lester Shields
> GFI's require a ground to actually work. Your RV may only have a ground
when
> you are connected to shore power. I don't know about you, but I have
> rubber-like tires on my RV that are on the ground, that makes the RV
pretty
> well insulated from the ground, hence no ground!
Wrong, wrong, wrong, wrong, wrong. GFI's, more correctly GFCI (Ground Fault
Circuit Interrupter) do not require a ground to work. They simply monitor
the current flowing through the hot and neutral circuits. As long as they
are equal, there is no ground fault (which is simply an unintended path to
ground). If there is an imbalance, the circuit is interrupted within
approximately one cycle (1/60 sec.). In fact, GFCIs are really more
important in ungrounded circuits than grounded ones. For example, consider
an electric drill. If the electric drill has a metal case, the ground lead
is supposed to be connected to the case.
Case 1- a grounded outlet: If there is an internal fault in the drill or
you drill into a hot wire, the case becomes energized. Since the case is
connected directly to ground via a low impedance circuit, virtually all the
current flows directly to ground via the green wire and almost none through
the person unfortunate enough to be holding it. In fact, unless that person
is well grounded, the current through him will be very small. However the
current the cord and to ground will be quite sufficient to trip the breaker
or blow the fuse.
Case 2 - an ungrounded outlet. Same internal fault. The drill case gets the
full 120 VAC which passes through the user to ground, assuming there is a
ground path (if the user is not grounded in some way, there is no current
flow). That's not pretty.
Case 3 - an ungrounded outlet with GFCI protection. The case gets energized
and current flows through the holder to ground, again assuming there is a
ground path. The current in the hot and neutral lead is unbalanced and the
GFCI trips instantly. User may not even feel the tingle.
Case 4 - grounded outlet with GFCI protection. All circuits should be wired
this way. There is double protection.
A three prong outlet without a ground connection would be a violation of
Code. Surely someone could be held liable for this.
Janet Wilder
Dud B." <steph...@att.net> writes:
>Due to the box size restriction, would he be better off just putting in a
>GFI breaker (if it fits)?
>As for surge suppression, you can buy suppressors that plug into the power
>cord from Camping World.
>--
Camping World sells a combination surge protector and low voltage protector
device. We have always had one and found it very valuable in CGs during
holiday weekends when everyone with a camper thinks they can run every
electrical device in their unit just because the RV came with them. The
company that makes the device is in Clearwater, FL and has been wonderful as
far as servicing and/or replacing our unit. It is not cheap, but well worth
the price to save your electrinics from surges and low voltage conditions
(which might be just as damaging). I'm not going to mention the product's
name, okay? <g>
Janet
The Road Princess
roadpr...@escapees.com
degirod
Recepts a lot less expensive than breakers
James Bott
> Install your GFI outlet the least distance from your main panel as all the
> other outlets are most likely on the same circuit anyway.
Well two outlets are on one wire and two on the other. So, I guess you are
saying that if I install GFI outlets in the first box, then second box will
be protected too? The refrig is also on one leg (after the first outlet), so
it will be protected also?
I forgot to mention that I do have three wire wiring, so I'm Ok there.
James Bott
San Diego
HHamp5246
<bobh...@go.com> writes:
>Wade, you have to find a more precise way to set your clock on the computer
than by stepping out on the porch and looking at the sun>>>><G>
I got this joke while I was reading this clock thread.... it's too appropos not
to send it along.......
A rather confident man walks into a bar and takes a seat next to a very
attractive woman named Mary. He gives her a quick glance, then casually looks
at his watch for a moment.
Mary notices this and asks, "Is your date running late?"
"No", he replies, "I just bought this state-of-the-art watch and I was
just testing it."
Intrigued, Mary says, "A state-of-the-art watch? What's so special about
it?"
"It uses alpha waves to telepathically talk to me," he explains.
"What's it telling you now?" Mary asks.
"Well, it says you're not wearing any panties..."
Mary just giggled and replies, "Well it must be broken then because I am
wearing panties!"
The man explains, "Damn thing must be an hour fast."
Will Sill
>Wrong, wrong, wrong, wrong, wrong. GFI's, more correctly GFCI (Ground Fault
>Circuit Interrupter) do not require a ground to work. They simply monitor
>the current flowing through the hot and neutral circuits. As long as they
>are equal, there is no ground fault (which is simply an unintended path to
>ground). If there is an imbalance, the circuit is interrupted within
>approximately one cycle (1/60 sec.). In fact, GFCIs are really more
>important in ungrounded circuits than grounded ones.
Good job. Strange that so many people have no understanding of the
GFI principle. You've explained it well. I would only add that the
typical GFI will trip at around 5 milliamps of fault current - WELL
below the level that most people can even sense.
Will KD3XR
One@home.com Wade
In that case you will need two GFI outlets, if your intent is to have both
runs protected, the only important consideration is that it must be the
first after the panel in order to protect the entire run.
Wade
Bob Hatch
news:20020125090414.28674.00000491@mb-
But, if this were Wade's watch it would most likely be an hour or so
slow...<g>
Carl A.
"Janet Wilder" <pri...@aol.comnoqspam> wrote in message
news:20020124234809...@mb-fm.aol.com...
> . . .I'm not going to mention the product's
Janet,
if you won't mention it because you can't remember the name, or because you have
a financial connection to the manufacturer, then OK.
But if you are doing so because of the recent unpleasantness regarding
advertising, then the NG terrorists have won.
This NG would lose 90% of its usefulness if people would not provide links
and/or company names.
--
Carl A.
http://pages.prodigy.net/chainnj/Journal.htm
Bob Hatch
understanding of electric wiring, get some help. In most GFIs they will have
connectors for Line, and Load and the sides that the wires go on are often
reversed from line to load.
FYI, line would be what is coming from the power source, load going to the
next plugin.
Bob Hatch
news:9ns25ugupmce0jcbn...@4ax.com...
2 years ago I had a 36 x 48 foot pole barn built and then enclosed 1/2 of
it. Wired up a shop and studio room myself. (Passed code and inspection.)
While doing the wiring I had one circuit that kept popping the GFI. There
were 4 plug ins down line from the GFI. Started disconnecting and testing 1
at a time. No solution.
Every time I disconnected the load wire from the GFI had no problem. Put in
new GFI, same problem.
Did a very close inspection of the wires and found that one of the cable
staples (wood studs) had cut the insulation on the romex and was just
touching the exposed black wire. Replaced romex, no problem.
w_tom
surge protection. Two completely different concepts.
Marc Allen has accurate discussed surge protection - which is for transistor
safety. Destructive surges are common mode transients. Earth ground, in
particular the length of wire to that earth ground - is essential for surge
protection. It is why plug-in surge protection is so ineffective - too far
from earth ground. A surge protector is only as effective as its earth ground
which should be less than 10 feet from the surge protector.
Lester Shields discussed GFCI which is for human safety. It operates in
response to differential mode currents - not common mode. GFCI don't require
earth grounding or breaker box grounding (they are different even though
connected) to operate. However, if a GFCI is used without grounding, then the
NEC *requires* the GFCI and all related outlets be marked with a specific phase
which I believe is "NO GROUND AVAILABLE". Don't assume this means earth
grounding is not necessary!
Marc has described a dangerous condition where the AC pole connection has no
safety ground wire. He has properly noted how to inspect for such but has
failed to note a dangerous condition that a two wire connection can create. If
that RV is isolated on rubber tires and the hot wire shorts internally, then
human life is endangeredwhen human steps from RV to earth. That safety ground
wire connection must exist from RV to AC pole - no exception! Even a GFCI is
not sufficient for human safety here.
Lester would have you believe that Marc was discussing GFCI. Marc discussed
surge protection. Lester discussed GFCI. They are two completely different
functions. And neither mentioned the critical need for safety ground (third)
wire in that AC pole hookup.
Human safety involves the cross sectional area of that critical ground wire.
Surge protection involves the length of that ground wire. Just another example
of why the two concepts are completely different although sharing the same
ground wire.
Janet Wilder
<cha...@prodigy.net> writes:
>"Janet Wilder" <pri...@aol.comnoqspam> wrote in message
>news:20020124234809...@mb-fm.aol.com...
>> . . .I'm not going to mention the product's
>> name, okay? <g>
>> Janet
>> The Road Princess
>> roadpr...@escapees.com
>
>Janet,
>
>if you won't mention it because you can't remember the name, or because you
>have
>a financial connection to the manufacturer, then OK.
I have no financial connection to the company.
>
>But if you are doing so because of the recent unpleasantness regarding
>advertising, then the NG terrorists have won.
>
You are right. The name of the company is TRC. They are located in
Clearwater, FL. They are an excellent company to do business with. I don't
know if they have retail sales. I don't have a web site. Camping World
carries the product. It comes in 50 amp and 30 amp models. They sell portable
and hard-wired versions. Ours has more than paid for itself in protecting our
electronics.
Janet
>This NG would lose 90% of its usefulness if people would not provide links
>and/or company names.
>
>--
The Road Princess
roadpr...@escapees.com
w_tom
Surge protectors are only as effective as their earth ground. Earth ground is THE
surge protection. Since we cannot earth ground every wire and still have service,
then we install a surge protector to make that earth ground connection only during
the surge. A surge protector is as effective as its earth ground connection.
A surge protector only shunts (shorts, diverts, connects) a surge from one wire
to all others. To sell to the naive, many publications will promote surge
protection by implying that they stop or absorb surges. Those internal components
(MOVs) don't work that way. They shunt a surge from one wire to all others. It
is why a surge protection located too close to an appliance can actually increase
probability of surge damage.
A surge seeking earth ground on the black wire finds an adjacent surge
protector. Now the surge can seek earth ground, destructively, through an
appliance on all three wires - black, white, and green. A surge protector adjacent
to appliances provides the surge with more destructive paths into the appliance.
A surge protector is only as effective as its earth ground - because earth ground
is the surge protection. That surge protector must connect a surge less than 10
feet to earth ground - shorter means even better protection. Plug-in surge
protectors are simply too far from earth ground and too close to appliances (as
well as undersized and overpriced) to be effective.
To be consistent with the original topic - surge protection and GFCI are two
completely different functions that address two completely different problems -
human safety and transistor safety.
w_tom
$50 or how much per protected RV appliance? Remember that even the GFCI is
another electronic appliance to be included in that count of protected
appliances.
Furthermore, how many joules is that other surge protector rated? Minimal
protection starts at 1000 joules and 50,000 amps. If the other surge protector
is a plug-in type, then it must be rated 3000 joules just to be equivalent.
Effective surge protection is as close to the earth ground rod (typically in
the AC power pole) as can be created. Distance short to earth ground and
distance far from the protected appliance are critical for effective surge
protection.
Jack Stevens
informative.
--
Jack Stevens
alarman2...@yahoo.com
remove NOSPAM to reply
w_tom wrote a lot of interesting stuff about grounding...
Chris Bryant
>Effective surge protection is as close to the earth ground rod (typically in
>the AC power pole) as can be created. Distance short to earth ground and
>distance far from the protected appliance are critical for effective surge
>protection.
That's why I generally do *not* recommend buying surge
protectors for RVs- they are only as good as the shore power ground.
But.. I suppose some protection is better than nothing.
James Bott
> James, please make sure you wire correctly. If you don't have a pretty
clear
> understanding of electric wiring, get some help. In most GFIs they will
have
> connectors for Line, and Load and the sides that the wires go on are often
> reversed from line to load.
>
> FYI, line would be what is coming from the power source, load going to the
> next plugin.
Thanks, that answers a question that came to mind while I was out in my MH
working on it. Regular outlets have the two terminals connected so I was
wondering how installing just one GFI outlet would protect the others. It
seems by your comments that the two terminals on GFI outlets are only
connected through the circuit breaker. Correct?
I do have a fair understanding of electricity and wiring.
James Bott
James Bott
than
> $50 or how much per protected RV appliance? Remember that even the GFCI
is
> another electronic appliance to be included in that count of protected
> appliances.
First, are you stating that a GFI outlet is not as good as a circuit
breaker? Note that all my AC appliances are on just two wire runs off the
same circuit. So, I could use just two GFI outlets at about $8 each to
protect everything.
Second, from what I was reading in another thread, RV circuit breakers may
not be interchanable with house-type breakers (due to physical differences).
Have you used the above mentioned ones in a RV?
> Furthermore, how many joules is that other surge protector rated?
Minimal
> protection starts at 1000 joules and 50,000 amps. If the other surge
protector
> is a plug-in type, then it must be rated 3000 joules just to be
equivalent.
Are you saying that if the wires are screwed together rather than plugged in
together that they are more effective?
James Bott
San Diego
James Bott
ineffective.
> Surge protectors are only as effective as their earth ground. Earth
ground is THE
> surge protection. Since we cannot earth ground every wire and still have
service,
> then we install a surge protector to make that earth ground connection
only during
> the surge. A surge protector is as effective as its earth ground
connection.
> A surge protector is only as effective as its earth ground - because
earth ground
> is the surge protection. That surge protector must connect a surge less
than 10
> feet to earth ground - shorter means even better protection. Plug-in
surge
> protectors are simply too far from earth ground and too close to
appliances (as
> well as undersized and overpriced) to be effective.
I do believe the one she is recommending plugs into the hookup pole and then
the RV cable plugs into it. As RVer's we can't get it any closer to ground
and any further from the appliances.
Perhaps you thought she was referring to the more common plug-in type that
you plug into the wall socket and then your appliance directly into the
surge protector?
James Bott
San Diego
James Bott
is
> surge protection. Two completely different concepts.
> Marc has described a dangerous condition where the AC pole connection
has no
> safety ground wire. He has properly noted how to inspect for such but has
> failed to note a dangerous condition that a two wire connection can
create. If
> that RV is isolated on rubber tires and the hot wire shorts internally,
then
> human life is endangeredwhen human steps from RV to earth. That safety
ground
> wire connection must exist from RV to AC pole - no exception! Even a GFCI
is
> not sufficient for human safety here.
If there is no ground wire, is it possible to create one using a metal stake
and wire to your RV's body?
Also, what about when dry camping using a generator? Do you need a physical
ground to earth?
James Bott
San Diego
Jim Redelfs
"James Bott" <jb...@compuserve.com> wrote:
> If there is no ground wire, is it possible to create one using a metal stake
> and wire to your RV's body?
I was wondering when someone would broach the topic of a ground rod. I
would be VERY careful (reluctant) about driving anything other than a
PLASTIC, 9-inch tent peg into the ground at most campgrounds. The water
lines, not to mention the power lines in some places are VERY shallow.
If a metallic water hydrant is present and convenient to the site,
bonding to IT would probably be the best. A metal sign post or other
structure would be my next choice. In order to be most effective, a
ground rod must be LONG and driven-in completely. This is NOT safe and
should NOT be done in a campground with underground utilites.
> Also, what about when dry camping using a generator? Do you need a physical
> ground to earth?
While I suspect it is mostly for safety, don't modern, portable gensets
REQUIRE an earth ground?
:)
JR
Bob Hatch
On most new ones I have used the load connections are covered with warning
tape. You will have to remove the tape to connect the down line plug-ins.
Also on the ones I have used the black wire to the line (circuit box) has
connected to the brass connector, white to silver and ground to green, the
load will connect to the opposite sides. Like I said, follow the
instructions closely.
Marc Alan
Actually what I've been finding is that many GFI's also have grounded
outlets or must be marked "non grounded". Since some RV's don't have ground
wires, I assumed the GFI related to that (no ground) rather than GFI's
"grounded" AC outlet stopping it from being installed in a MH with no
ground. It never occured to me that a "Ground Fault Interrupter" had nothing
to do with a "Ground". Sorry for assuming.
I use an extension cord for my electronics from the rv to the ac box with a
GFI and Surge supressor on the ac box end. If no seperate outlets exists in
the campground (or if running on the generator), I just plug it in to a
kitchen outlet.
Marc Alan
Just out of curiosity, does anyone know what a joule actualy is? I can't
find a definition of it anywhere.
w_tom
HHamp5246
>> find a definition of it anywhere.
joule \"jul\ n : a unit of work or energy equal to the work done by a force of
one newton acting through a distance of one meter
Mirriam-Webster
w_tom
the ground must connect to breaker box safety ground so that any shorted hot wire
will trip circuit breakers. This was demonstrated in an example of an electric
drill that hits an electrical hot wire.
Again, for human safety, the RV chassis must be at the same voltage as earth.
Therefore the wet human stepping into or out of an RV will not conduct
electricity. This is accomplished by the ground wire that connects the RV to AC
pole. It assumes the pole has the critical connection to earth ground. Inspect
that pole for proper earthing.
Just connecting an RV to an earth ground such as a buried water pipe is not
sufficient. Such a connection does not also connect to breaker box ground. It
does not provide a satisfactory circuit to trip the circuit breaker.
An underlying principal - breaker box safety ground and earth ground are not the
same. They may be interconnected, but they are still different.
Described are grounds for human safety. Grounding for surge protection involves
different current flows, although both currents may also use the same ground
wires.
Even if a GFCI outlet is not connected to safety ground, still the AC pole must
connect the RV chassis to pole safety ground. That AC pole connection must have a
safety ground wire regardless of GFCI inside the RV.
BTW, there is this often repeated example from the military. A communications
truck failed to earth a ground rod. Someone took a piss from the truck and
discovered what happens when a mobile vehicle is isolated from earth. It has been
described as extremely painful.
George E. Cawthon
You're kidding. Joule is a unit of work equal to 10 to the
7th ergs,
9.480 x 10 to -4 BTU, 0.7376 foot-pounds, or 2.778 x 10 to
-4th watt-hours. You could also convert it to
dyne-centimeters, gram-calories, gram-cms, horsepower-hours,
kg-calories, etc.
Lester Shields
"w_tom" <w_t...@usa.net> wrote in message news:3C51E55F...@usa.net...
> Lester has confused Marc's post and the issues. One is GFCI. The other
is
> surge protection. Two completely different concepts.
>
> Lester would have you believe that Marc was discussing GFCI. Marc
discussed
> surge protection. Lester discussed GFCI. They are two completely
different
> functions. And neither mentioned the critical need for safety ground
(third)
> wire in that AC pole hookup.
I confused nothing. I said nothing about surge protection. I simply
responded to a post that stated that GFIs require a ground to work. They
still don't.
Les
w_tom
rereading her post, I was probably incorrect. A surge protector connected short
to the AC pole is indeed effective surge protection from destructive surges from
the campground.
One additional requirement of effective surge protection is its joules
rating. That surge protection should, at minimum be rated 1000 joules, 50
Kamps. Joules (a measure of energy) represents the life expectancy of a surge
protector. More joules means that it will withstand an exponentially increasing
number of surges.
w_tom
the GFCI believes it was connected properly. Purchase a three prong AC plug and
two 1/2 watt 15Kohm (or 18K ohm) resistors. The two 15K 0.5 watt resistors
connect, in parallel from the AC hot prong (smaller of two rectangular prongs)
to the safety ground prong. When plugged into a GFCI protected outlet, this
tester will trip the GFCI. Use this tester for every GFCI outlet. If the
outlet does not trip a GFCI, the resistors will simply become warm - only about
1 watt of heat.
Marc Alan
car hits a power pole?
How many joules does it take to get out of a wet paper bag? (sorry, couldn't
resist adding some humour)
"w_tom" <w_t...@usa.net> wrote in message news:3C522A8B...@usa.net...
Marc Alan
> >
> > Just out of curiosity, does anyone know what a joule actualy is? I can't
> > find a definition of it anywhere.
>
> You're kidding. Joule is a unit of work equal to 10 to the
> 7th ergs,
> 9.480 x 10 to -4 BTU, 0.7376 foot-pounds, or 2.778 x 10 to
> -4th watt-hours. You could also convert it to
> dyne-centimeters, gram-calories, gram-cms, horsepower-hours,
> kg-calories, etc.
Anything a bit less esoteric and that can be converted to something that
makes sense in surge suppressor ratings? Remember us ordinary folk buy surge
suppressors, not electrical engineers.
Marc Alan
"HHamp5246" <hham...@aol.comnospam> wrote in message
news:20020125224819...@mb-fq.aol.com...
Thats what I kept finding, one term defined by another. Any idea what a
"Newton" is and how does it relate to electrical stuff (like ratings in
surge suppressors?)
w_tom
ungrounded GFCI outlet.
w_tom wrote:
> Having installed a GFCI so that you believe it works - now tester to see
> if the GFCI believes it was connected properly. Purchase a three prong
> AC plug and two 1/2 watt 15Kohm (or 18K ohm) resistors. ...
w_tom
Joules determines the life expectancy of a surge protector. As joules
increase, life expectancy increases exponentially. Any surge protector that
'smoked' during a surge is not just undersized. It was grossly undersized.
It had way too few joules. However some may use a different unit of measure.
They might say it had no balls.
Tom
It's not a cookie. It's cake with a fig filling.
Tom
bill horne
A joule is a watt-second.
A kilowatt-hour is 3600000 joules.
Tripplite says 200 is basic, 400 is good, and 600 or more is great.
--
bill
Theory don't mean squat if it don't work.
Marc Alan
has a rating of 3,000 joules it has 3 balls? Where does exponential come in?
wouldn't it be arithmetic rather than exponential (3 X 1000 rather than
1000X1000X1000)? Any idea what happens if you plug one into another? Are 3
1000 joules suppressors in series 3000? I recall someone here wondering
about putting light bulbs in series on a 220V well pump circuit and the
lights would last a long time. I sort of wonder if there is some way of
making the lower joule units work like a higher joule unit and have the
second or third one survive when the first one fails from a surge.
"w_tom" <w_t...@usa.net> wrote in message news:3C523109...@usa.net...
w_tom
Now because of where it is located and therefore wired, the plug-in surge
protector will provide as little as 115 joules of protection and never more than
230. We will assume it is a 115 joule unit. If joules related to life
expectancy linearly, then a 1,000 joule unit would last 8.7 times longer.
Based upon price, the 'whole house' unit already is a good deal. But the
relationship is exponential.
Assume that each surge is the standard model 8/20 usec type and that all
surges are equal power so that the 115 joule protector survives 3 surges. Then
the 1000 joule unit would survive 2500 such surges. Again, it is an exponential
relationship. Notice what a better deal that 'whole house' surge protector is.
More joules means an exponential increase in life expectancy.
Why is this concept of joules so little understood? Those 345 joule power
strip manufacturers are the source of most layman knowledge on surge
protection. Since their product is so often undersized, then they simply avoid
discussion of joules. Better to let you think joules is some magical number so
that you will spend $20 or $50 on ineffective surge protection rather than less
than $50 for effective 'whole house' protection. Those components inside that
345 joule power strip cost less than $0.25 each. Since they markup a $3 power
strip to $20+ by adding insufficient components (joules), then why would they
discuss joules. You might then start asking another embarrassing question about
the missing earth ground connection.
w_tom
functional component - the MOV. However the purpose of a surge protector is
not to absorb or stop a surge. It's purpose is to shunt energy from one wire to
the other.
An MOV is like an open, or OFF switch. But when a surge is detected, it must
close or turn ON to shunt (short) that energy into the other wire - hopefully
earth ground. However, MOVs are not perfect. Even wires are not perfect
conductors. Therefor the MOV, unfortunately, absorbs some energy. A 100 joule
MOV can absorb up to 100 joules while conducting much more energy into earth.
As previously noted, life expectancy is an exponential function. So a surge
that passes through a 100 joule MOV will be more absorbed by the smaller MOV
compare to a surge through a 1000 joule MOV. As joules increase, then the
amount of absorb energy decreases significantly.
A 1000 joule surge protector will shunt more energy into earth and will absorb
much less energy than a 100 joule unit trying to do same for that surge.
I don't know the relationship between joules and balls so I cannot
(thankfully) demonstrate it.
Marc Alan
Protector Strip With 1000 Joules LOWE'S PRICE: $10.99) can I put three of
em in series and have 3000 joules of protection for under $33? (I didn't see
where you said anything about putting em in series). Would that make the
combination good for 7500 (2500 * 3) surges? Something else I don't
understand, the package says 1000 Joules, the ad says 1000 joules, but when
you open the box and read the fine print in the manual it says
"330volt/400joule capacity" Why the difference? How do they calculate 1000
joules out of that? Isn't that an example of "false advertising"? And once
again, what the heck IS a Joule, and how is someone with a measly college
education supposed to know what the heck a "Joule" is anyway? Maybe it can't
be false advertising since nobody knows what a joule is supposed to be
anyway?
At any rate, the site I am in at the moment has separate 15/20 AMP plugs in
the electrical box. I was thinking about plugging a GFI in at the box with a
15 AMP 50 FT. outdoor cord run into the RV, and then multiple strips in the
RV at the other end of the extension cord so I would have a whole mess of
plugs with protected power, and if the protection is additive, could even
plug my computer/tv/etc into the last strip to get even more protection. For
those wondering "why bother", I have a mid 80's MH that only has two wire
romex throughout the rig (no ground, the RV does have regular AC outlets,
the grounds aren't connected to anything). I'm looking for a cheap way to
protect some of the more sensitive AC equipment at least. This seems like it
may work. Any thoughts?
"w_tom" <w_t...@usa.net> wrote in message news:3C52530D...@usa.net...
Pete Dumbleton
>> Every time I disconnected the load wire from the GFI had no
problem. Put in
> new GFI, same problem.
>
> Did a very close inspection of the wires and found that one of the cable
> staples (wood studs) had cut the insulation on the romex and was just
> touching the exposed black wire. Replaced romex, no problem.
That's why the elec contractors don't like GFCI; they have to fix the
problem to make it work. And typically, they don't find the problem
until the mistake is covered by other contractors and costly to fix.
That cable staple, if covered by drywall so no one could actually
touch it, could have remained safely in the wall for the life of the
barn with no likely problems had it not been on a GFCI-protected run
(I will allow that someone punching thru the drywall with a bare fist
could touch the "hot" staple, or in the right moisture conditions it
might get hot enuf to do damage, but these scenarios are rather
unlikely, IMHO).
Pete
Pete Dumbleton
> ground. It never occured to me that a "Ground Fault Interrupter" had nothing
> to do with a "Ground". Sorry for assuming.
>
I suspect the ground part comes from the fact that to have a problem,
there must be no connection from hot to ground until a (wet) human
comes along and makes it the hard way, as in the case of an rv skin or
a metal drill case just sitting there with an open ground and the hot
and neutral wires reversed....\
Pete
HHamp5246
<mscho...@NOSPAM.sc.rr.com> writes:
>So if a surge suppresor has a rating of a 1,000 joules (1 ball) and another
>has a rating of 3,000 joules it has 3 balls?
But, "Family Joules" usually have.......
Oh nevermind.
Hunter
Lone Haranguer
w_tom wrote:
>
> Joules rating is not the energy of a surge. It is the energy absorbed by a
> functional component - the MOV. However the purpose of a surge protector is
> not to absorb or stop a surge. It's purpose is to shunt energy from one wire to
> the other.
>
> An MOV is like an open, or OFF switch. But when a surge is detected, it must
> close or turn ON to shunt (short) that energy into the other wire - hopefully
> earth ground. However, MOVs are not perfect. Even wires are not perfect
> conductors. Therefor the MOV, unfortunately, absorbs some energy. A 100 joule
> MOV can absorb up to 100 joules while conducting much more energy into earth.
>
> As previously noted, life expectancy is an exponential function. So a surge
> that passes through a 100 joule MOV will be more absorbed by the smaller MOV
> compare to a surge through a 1000 joule MOV. As joules increase, then the
> amount of absorb energy decreases significantly.
>
> A 1000 joule surge protector will shunt more energy into earth and will absorb
> much less energy than a 100 joule unit trying to do same for that surge.
>
> I don't know the relationship between joules and balls so I cannot
> (thankfully) demonstrate it.
I'm hollering "uncle" Tom! I've already read more about surge
protection than I ever wanted to know. I think the cheaper option is to
have low deductible insurance and stop worrying about it.
LZ
James Bott
> Again, for human safety, the RV chassis must be at the same voltage as
earth.
> Therefore the wet human stepping into or out of an RV will not conduct
> electricity. This is accomplished by the ground wire that connects the RV
to AC
> pole. It assumes the pole has the critical connection to earth ground.
Inspect
> that pole for proper earthing.
Exactly how can we determine if the pole is properly "earthed?"
> Just connecting an RV to an earth ground such as a buried water pipe is
not
> sufficient. Such a connection does not also connect to breaker box
ground. It
> does not provide a satisfactory circuit to trip the circuit breaker.
Isn't the breaker box grounded (connected) to the RV body?
> An underlying principal - breaker box safety ground and earth ground are
not the
> same. They may be interconnected, but they are still different.
>
> Described are grounds for human safety. Grounding for surge protection
involves
> different current flows, although both currents may also use the same
ground
> wires.
>
> Even if a GFCI outlet is not connected to safety ground, still the AC
pole must
> connect the RV chassis to pole safety ground. That AC pole connection
must have a
> safety ground wire regardless of GFCI inside the RV.
Ok, I don't mind a little theory, or even a little criticism, but how about
some practical solutions in laymen's terms for us? You certainly seem to
have the knowledge to be able to tell us.
1) How do we determine if the hookup pole is properly grounded? What can we
do, if anything, to correctly ground our RVs if the pole is not properly
grounded? (Assume we want safety, surge protection, and working GFIs).
I do have a little plug-in device that supposedly tells you if the circuit
is wired correctly and if it is grounded. Is this sufficient?
2) What about when dry camping and running a generator? Do we need an Earth
ground? If so, how do we accomplish this?
3) What are the desired specs for a surge suppression system for an RV.
Perhaps good, better, and best descriptions would be helpful for those who
can't afford the very best or don't have as much at stake.
Note: Thanks for the description of how to make a GFI tester. This is just
the kind of practical advice we need.
James Bott
San Diego
w_tom
Depot for less than $50. If mounted where AC power cord enters, than that power
cord must be three wire. A short safety ground (to the pole's earth ground) is
essential to surge protection even if RV outlets are only two wire.
Three Lowes power strips still would not be as effective. A 6 foot power
cord, then wire to the breaker box, then wire to the power pole. Distance is
critical. That 'too long' connection to earth ground means ineffective
protection. Furthermore, if AC outlets are only two wire, then no plug-in surge
protector can be effective. Connection to earth ground is THE most critical
connection. A surge protector is only as effective as its earth ground.
Those three ineffective Lowe's power strips have cost more money compared to
'whole house' protection.
Putting power strips in series only degrades their performance. Surge
protection to stop surges is in series. You don't stop surges. Surge
protection to divert surges is in parallel. Those power strips should all be
plugged separately into outlets - to be connected in parallel. But again, your
outlets have no earth ground - no surge protection is possible from outlets.
Your only alternative is a 'whole house' unit and a short connection to earth
ground.
Joules - a measure of surge protector life expectancy.
Why is a 1000 joule surge protector only rated at 400 after purchased?
Maybe it is 900 joules on AC and 100 joules on the phone. But if the 900 can
only provide 300 during a surge, then 300 joule AC protection and the 100 joule
phone line protection is 400 joules. How those 900 become 300 was detailed
previously. This is only wild speculation but it demonstrates how total
joules numbers are calculated.
As for 330 volts, that surge protector does nothing productive until the 120
VAC wires exceed 330 volts.
w_tom
missing 'safety' ground. But they do not report that 'safety' ground is good
nor do they test for 'earth' ground.
The only way to verify the existence of earth (pole) ground is visual
inspection. Obviously you are at the mercy of the electricians work standards
inside a breaker box. But earth ground is usually compromised where it can be
observed. Of course, you cannot determine if the ground rod is the minimal 8
foot - some electrician do cheat. But that ground rod must be firmly in contact
with earth. However, quality of earth is also a contributing factor. Grounds
in sand are woefully insufficient. They can also be improved or compromised by
what is below the surface.
The only part you can verify is bare wire connection and ground rod firmness -
visually.
Another critical surge protection ground. A transformer pole ground must
also be visually inspected - also for your surge protection. Lightning striking
a transformer without earthing can short the utility's 13K volts into your RV's
120 VAC. Lightning does not contain high energy. But a shorted 13K can dump
high energy into an RV. 'Whole house' surge protection has demonstrated
protection from such transformer failure. But visual inspection of that ground
wire and rod is still recommended.
Whether home or RV, a minimal 'whole house' protection starts at 1000 joules.
We use earth ground to connect the utility generator and the consumer to a
common "ground". The local generator and the consumer in an RV must also share
a common "ground". An RV chassis serves the same "ground" purpose to a local
generator as earth does to the utility generator.
The utility goes to substantial effort to connect its generator to your common
earth ground. You must go to same effort to connector your generator to your
common chassis ground.
James Bott wrote:
> ...
w_tom
transistors either.
Lone Haranguer
w_tom wrote:
>
> Uncle Tom's cabin never burned down from a lightning strike. But then it never had
> transistors either.
>
The internet will give you maps of where lightning strikes are
occurring. Hook up and drive like hell and stop worrying about surge
protection!
BTW what protection from surges am I getting if I am plugged into a
Trace inverter? It claims to have built-in protection against surges.
I run my sensitive stuff off a surge-protected power strip plugged in to
the inverter which is then plugged into a standard outlet. Usually if
thunderstorms are in the area I just unplug the motorhome and run on
batteries until the storms have moved on.
LZ
w_tom
an input power surge called load dump. A problem when a wire intermittent or something
equivalent causes the alternator to dump a large current into a changing load. It is more
common in older engines. A load dump is defined typically as 60 V on the 12 volt system.
Newer vehicle specs seem to claim 45 volts. There are IEC and SAE standards that define
the problem.
Industry standard voltage regulators such as the single chip 5 volt (7805) are only rated
up to 35 volts input. They would be destroyed by load dump. Special power supply parts
for auto applications or other solutions are installed in all automotive electronics to
avoid a load dump failure. SGS Thompson sells a solution (app notes available on their web
site by searching for 'load dump') that must be incorporated in newer alternators. They
admit the solution is good but still not sufficient (an honest application note writer).
Therefore the inverter would require protection from a differential mode surge called load
dump.
Many plug-in UPSes recommend not plugging a surge protector in their outputs. Inverters
output dirtier electricity. Some power strips (before UL1449 2nd edition) were reported to
catch fire because of those inverter noise spikes.
Power strip surge protectors have a limited life expectancy. Therefore they are speced
at voltages above 330 volts. If an MOV surge protector (set to a voltage well below 300
volts) was confronting daily surges from, say, a refrigerator, then it would be toasted by
the end of the week or month.
However semiconductor based surge protectors are not subject to life expectancy problems
(and are therefore not rated in joules). Their threshold or let-through voltage is more
like 200 volts. IOW, they can shunt both surges and noise spikes without degradation.
However, such surge protectors may result in excessive loading of the inverter.
Information on this compatibility issue is quite difficult to obtain. Use of an
oscilloscope may be required. Instead I would place an in-line filter (ie Corcom,
Shurter, etc) on sensitive stuff just to supplement existing filters in that inverter.
Filters would not short out the inverter when the inverter output a noise spike. It is
that shorting that caused some power strip surge protectors to destroy the plug-in UPS's
output inverter.
Lone Haranguer
I think I'll keep depending on good luck then. I have used the present
inverter and surge-protected power strip in 3 motor homes since March of
'95. I have a 4.8 cu. ft. freezer also plugged into the strip which
pegs the ammeter on the negative side when it starts up. When going
down the road the alternator is running things through the inverter.
When dry camping the battery bank or generator is doing it. With
hookups it's shore power. If I run the batteries down, the alternator
will start out charging over 20 amps. So far no smoke or fire and my
laptop, TV,VCR, DSS receiver and freezer have all survived whatever
spikes have occurred. I've stayed in many campgrounds and hooked up to
some primitive 20 amp and modern 50 amp sites without a problem. Check
out the TRACE 800 watt inverter with built-in charger. It seems to
furnish pretty "clean" 110V power.
LZ