Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
Retrofit-Grounding Fifties-Era House?
75 views
Skip to first unread message
(PeteCresswell)
Nov 15, 2012, 7:02:05 PM11/15/12
to
I tried this in misc.rural, and got a recommendation to try it
here.
-------------------------------------------------------------
Been quite awhile since I started wondering what it was with the
"Building Wiring Fault" lights on my UPS'.
In doing some homework prior to getting a generator transfer
switch installed, it became apparent that houses need tb
"Grounded" - and the typical ground is one or more copper rods
pounded into the ground and then attached to a (neutral?) wire in
the breaker panel.
This house is a split-level, crawl space but no basement, built
in the fifties and I am unable to find anything that even looks
like a ground.
One reason for no ground might be what the house is built on: a
shale ridge. The builder scooped a notch out of a hillside,
sold the topsoil, and built this house on the notch. Go down
about 4", and you hit shale that is so solid that you need an air
hammer or a breaker bar and lots of time to get through - as in 3
days with a breaker bar and a tin cup to make 2 4" wide 28" deep
holes for a boat rack I put in last year.
Realistically, we've been in this house for 30+ years and never
lost an appliance to electrical surge... but still... there's got
tb good reasons for grounding.
That being said, I'm exploring after-the-fact methods.
The obvious is the copper pipe that water comes in on: buried
several feet deep and running a good 30' to the main under the
street. Seems like this was SOP until some time in recent
history when it was deemed inadequate.
The second thing that comes up is a "Ufer" ground wherein the
ground wire is tied to rebar in the house's foundation. I can
find a lot of articles on the techniques of doing this in new
construction, but nothing about retrofits.
The third approach seems tb lateral: long trenches in the yard
with the grounding medium layed in the trench. Seems
impractical to me bc the standard calls for 30" deep...
Has anybody been here: retrofitting a ground system to a house
built on shale or rock?
--
Pete Cresswell
here.
-------------------------------------------------------------
Been quite awhile since I started wondering what it was with the
"Building Wiring Fault" lights on my UPS'.
In doing some homework prior to getting a generator transfer
switch installed, it became apparent that houses need tb
"Grounded" - and the typical ground is one or more copper rods
pounded into the ground and then attached to a (neutral?) wire in
the breaker panel.
This house is a split-level, crawl space but no basement, built
in the fifties and I am unable to find anything that even looks
like a ground.
One reason for no ground might be what the house is built on: a
shale ridge. The builder scooped a notch out of a hillside,
sold the topsoil, and built this house on the notch. Go down
about 4", and you hit shale that is so solid that you need an air
hammer or a breaker bar and lots of time to get through - as in 3
days with a breaker bar and a tin cup to make 2 4" wide 28" deep
holes for a boat rack I put in last year.
Realistically, we've been in this house for 30+ years and never
lost an appliance to electrical surge... but still... there's got
tb good reasons for grounding.
That being said, I'm exploring after-the-fact methods.
The obvious is the copper pipe that water comes in on: buried
several feet deep and running a good 30' to the main under the
street. Seems like this was SOP until some time in recent
history when it was deemed inadequate.
The second thing that comes up is a "Ufer" ground wherein the
ground wire is tied to rebar in the house's foundation. I can
find a lot of articles on the techniques of doing this in new
construction, but nothing about retrofits.
The third approach seems tb lateral: long trenches in the yard
with the grounding medium layed in the trench. Seems
impractical to me bc the standard calls for 30" deep...
Has anybody been here: retrofitting a ground system to a house
built on shale or rock?
--
Pete Cresswell
gregz
Nov 15, 2012, 8:14:08 PM11/15/12
to
a pole ?
Greg
(PeteCresswell)
Nov 15, 2012, 8:24:28 PM11/15/12
to
Per gregz:
Could that be something the electric utility would be willing to
do?
I'm thinking maybe some sort of equipment or even personnel
safety concern.
--
Pete Cresswell
>I would want an evaluation of the current hookup from the pole. Do you have
>a pole ?
Yes.
>a pole ?
Could that be something the electric utility would be willing to
do?
I'm thinking maybe some sort of equipment or even personnel
safety concern.
--
Pete Cresswell
gregz
Nov 15, 2012, 8:56:43 PM11/15/12
to
requirements. If things were changed, then power company should inspect
before meter was attached.
Greg
Bob F
Nov 15, 2012, 10:17:01 PM11/15/12
to
"(PeteCresswell)" <x...@y.Invalid> wrote in message
news:9h0ba8d1m8hghgu83...@4ax.com...
guy who has to approve the instalation for your permit. He knows best what he
will approve. I've found they are glad to be consulted on such matters.
bob haller
Nov 15, 2012, 11:58:57 PM11/15/12
to
there are hammer tools designed to install ground rods which are
currently coper coated stell for strength
cr...@everywhere.com
Nov 16, 2012, 2:38:28 AM11/16/12
to
On Thu, 15 Nov 2012 19:02:05 -0500, "(PeteCresswell)" <x...@y.Invalid>
wrote:
That's simple.
Drill a hole all the way thru the core of the earth. Eventually, the
drill will exit somewhere in China. Run a copper wire all the way thru
this hole, and connect the far end of the wire to the ground rod of
whoever has the closest house to your hole, in China. Then connect the
near end to your breaker box ground bar.
That's all there is to it!
Plus, there's MORE.....
If your house ever gets hit by lightning, some idiot in China might get
electrocuted. That's the price they pay for hating Americans.
wrote:
Drill a hole all the way thru the core of the earth. Eventually, the
drill will exit somewhere in China. Run a copper wire all the way thru
this hole, and connect the far end of the wire to the ground rod of
whoever has the closest house to your hole, in China. Then connect the
near end to your breaker box ground bar.
That's all there is to it!
Plus, there's MORE.....
If your house ever gets hit by lightning, some idiot in China might get
electrocuted. That's the price they pay for hating Americans.
tra...@optonline.net
Nov 16, 2012, 7:54:49 AM11/16/12
to
>
> - Show quoted text -
Have you pulled the panel cover off and looked inside?
The ground wired would be inside, tied together with the
neutral. This was standard practice in the 50's. In the 50's
having the system grounded was already standard practice.
Back then, likely they would have tied it to the water pipe.
But it's also possible there is a ground wire going somewhere.
bud--
Nov 16, 2012, 9:07:50 AM11/16/12
to
On 11/15/2012 6:02 PM, (PeteCresswell) wrote:
> I tried this in misc.rural, and got a recommendation to try it
> here.
> -------------------------------------------------------------
> Been quite awhile since I started wondering what it was with the
> "Building Wiring Fault" lights on my UPS'.
>
> In doing some homework prior to getting a generator transfer
> switch installed, it became apparent that houses need tb
> "Grounded" - and the typical ground is one or more copper rods
> pounded into the ground and then attached to a (neutral?) wire in
> the breaker panel.
I assume this is the US, and there is an electrical code that is
> I tried this in misc.rural, and got a recommendation to try it
> here.
> -------------------------------------------------------------
> Been quite awhile since I started wondering what it was with the
> "Building Wiring Fault" lights on my UPS'.
>
> In doing some homework prior to getting a generator transfer
> switch installed, it became apparent that houses need tb
> "Grounded" - and the typical ground is one or more copper rods
> pounded into the ground and then attached to a (neutral?) wire in
> the breaker panel.
substantially the same as the National Electrical Code.
There are several major elements to the building "ground" system.
One is a bond between the neutral and service panel enclosure. The
enclosure is the basic system "ground". The bond may be a visible strap.
It can be a screw that just looks like a mounting screw for the neutral
bar. This bonding is critical for tripping breakers when there is a
short from, for instance, the hot wire in a drill to the metal drill
case that is connected to the ground pin at a grounded receptacle.
Another element is one or more earthing electrodes. They are not for
tripping breakers. They keep the building "ground" at approximately
earth potential, and keep the hot and neutral wires at a reasonable
potential with respect to earth.
The third element is grounding conductors that go with the branch
circuit and connect to the ground terminal on receptacles. The grounding
conductor can be a bare or green wire, or it can be the metal of the
wiring system.
I would understand "building wiring fault" to mean that there is no
branch circuit grounding conductor or there is no neutral-ground bond at
the panel. The UPS has no way of telling if the building "ground" is
earthed.
>
> This house is a split-level, crawl space but no basement, built
> in the fifties and I am unable to find anything that even looks
> like a ground.
>
> One reason for no ground might be what the house is built on: a
> shale ridge. The builder scooped a notch out of a hillside,
> sold the topsoil, and built this house on the notch. Go down
> about 4", and you hit shale that is so solid that you need an air
> hammer or a breaker bar and lots of time to get through - as in 3
> days with a breaker bar and a tin cup to make 2 4" wide 28" deep
> holes for a boat rack I put in last year.
>
> Realistically, we've been in this house for 30+ years and never
> lost an appliance to electrical surge... but still... there's got
> tb good reasons for grounding.
>
> That being said, I'm exploring after-the-fact methods.
>
> The obvious is the copper pipe that water comes in on: buried
> several feet deep and running a good 30' to the main under the
> street. Seems like this was SOP until some time in recent
> history when it was deemed inadequate.
earthing electrode. A metal water service pipe and metal municipal water
system is still the best earthing electrode you will find at a house.
Relatively recently a "supplemental" electrode has been required because
the metal water service pipe can be replace by plastic in the future.
The the N-G bonded service bar should have been connected to your water
pipe (#6 wire is usually used for 100A services), and a bonding wire
should have been connected across the water meter. The code now wants
the wire from the panel to connect within 5 feet of where the water pipe
enters the house. This will be your best earthing electrode.
>
> The second thing that comes up is a "Ufer" ground wherein the
> ground wire is tied to rebar in the house's foundation. I can
> find a lot of articles on the techniques of doing this in new
> construction, but nothing about retrofits.
before the foundation is poured.
>
> The third approach seems tb lateral: long trenches in the yard
> with the grounding medium layed in the trench. Seems
> impractical to me bc the standard calls for 30" deep...
>
> Has anybody been here: retrofitting a ground system to a house
> built on shale or rock?
rods are about the worst electrode.
Ask the electrical inspector what they would recommend.
(PeteCresswell)
Nov 16, 2012, 9:49:53 AM11/16/12
to
Per bob haller:
box in two places. I was looking for that woven flexy stuff
that appears in so many photos - and the patina made it look like
an old telephone cable.
One runs through a wall, down behind a drain spout, and
disappears into the garden soil next to the house.
The other runs along the ceiling, into the furnace room, and
attaches to a cold water pipe.
I think I'll pursue gregZ's recommendation and find somebody who
can tell me if the system is actually working (in light of the
"Ground Fault" lights on various UPS'). Maybe the guy who
installs the cutover switch...although I have learned the hard
way that not just any electrician chosen at random is what I'd
call a craftsman.... Competence I don't know enough to judge...
but the appearance of some of their work makes me wonder -)
One thing I don't like is that the 6mm copper is bundled in with
an RG6 TV cable and several Cat5 Ethernet cables on it's way to
the water pipe. Unencumbered by any knowledge, I have to wonder
if a high voltage spike grounding out along that copper might
bleed over and fry whatever Ethernet or TV devices are on the
ends of those cables. Or can I trust it to completely take the
path of least resistance?
While looking for the elusive house ground, I noted that the TV
antenna we had installed several years ago has a long ground
wire, but no ground. The wire is just coiled up in the garden
soil next to the house under the antenna. I guess Job#1 (after
a call to the installer....) is to run that wire through the
crawl space and mate it up with a cold water pipe. ??
--
Pete Cresswell
>look for ground wire coming down side of pole.
I think I found it: 6mm solid copper coming out of the breaker
box in two places. I was looking for that woven flexy stuff
that appears in so many photos - and the patina made it look like
an old telephone cable.
One runs through a wall, down behind a drain spout, and
disappears into the garden soil next to the house.
The other runs along the ceiling, into the furnace room, and
attaches to a cold water pipe.
I think I'll pursue gregZ's recommendation and find somebody who
can tell me if the system is actually working (in light of the
"Ground Fault" lights on various UPS'). Maybe the guy who
installs the cutover switch...although I have learned the hard
way that not just any electrician chosen at random is what I'd
call a craftsman.... Competence I don't know enough to judge...
but the appearance of some of their work makes me wonder -)
One thing I don't like is that the 6mm copper is bundled in with
an RG6 TV cable and several Cat5 Ethernet cables on it's way to
the water pipe. Unencumbered by any knowledge, I have to wonder
if a high voltage spike grounding out along that copper might
bleed over and fry whatever Ethernet or TV devices are on the
ends of those cables. Or can I trust it to completely take the
path of least resistance?
While looking for the elusive house ground, I noted that the TV
antenna we had installed several years ago has a long ground
wire, but no ground. The wire is just coiled up in the garden
soil next to the house under the antenna. I guess Job#1 (after
a call to the installer....) is to run that wire through the
crawl space and mate it up with a cold water pipe. ??
--
Pete Cresswell
(PeteCresswell)
Nov 16, 2012, 10:37:51 AM11/16/12
to
Per tra...@optonline.net:
They used solid copper instead the woven flexy stuff I was
looking for... so it took awhile to recognize it.
In the context of the "Ground Fault" warnings from various UPS',
though, I still think I need to have the ground electrically
verified... I'm guessing there are tools for that and it's just a
matter of finding the right person with the right tool.
--
Pete Cresswell
> In the 50's
>having the system grounded was already standard practice.
>Back then, likely they would have tied it to the water pipe.
>But it's also possible there is a ground wire going somewhere.
Bingo for both.
>having the system grounded was already standard practice.
>Back then, likely they would have tied it to the water pipe.
>But it's also possible there is a ground wire going somewhere.
They used solid copper instead the woven flexy stuff I was
looking for... so it took awhile to recognize it.
In the context of the "Ground Fault" warnings from various UPS',
though, I still think I need to have the ground electrically
verified... I'm guessing there are tools for that and it's just a
matter of finding the right person with the right tool.
--
Pete Cresswell
Mr.E
Nov 16, 2012, 11:55:00 AM11/16/12
to
On Fri, 16 Nov 2012 10:37:51 -0500, "(PeteCresswell)" <x...@y.Invalid>
wrote:
Possible that the ups is looking for a device ground at the outlet and
does not have continuity back to the panel. It has no way to measure
the complex ground/neutral panel connection.
A voltmeter can be used to verify the ground integrity at the outlet.
A 25 watt test bulb will indicate if the ground has a high impedance
even though shown to exist by the voltmeter.
Your house ground seems to be of the older rod plus pipe standard that
was prevalent when built.
--
Mr.E
wrote:
does not have continuity back to the panel. It has no way to measure
the complex ground/neutral panel connection.
A voltmeter can be used to verify the ground integrity at the outlet.
A 25 watt test bulb will indicate if the ground has a high impedance
even though shown to exist by the voltmeter.
Your house ground seems to be of the older rod plus pipe standard that
was prevalent when built.
--
Mr.E
tra...@optonline.net
Nov 16, 2012, 3:26:46 PM11/16/12
to
On Nov 16, 10:37 am, "(PeteCresswell)" <x...@y.Invalid> wrote:
> Per trad...@optonline.net:
The UPS would have no way of knowing if there is an
actual earth ground of not. It could have a way of knowing
if the outlet ground is connected to the neutral, but that's
it.
There are two issues. One is if the panel has an earth
ground, which you have now verified. The other is if
the grounds from outlets are in fact connected back
to the panel ground. If you're having problems with
UPS faults about ground, I would suspect that the outlet
does not have a ground path back to the panel.
> Per trad...@optonline.net:
actual earth ground of not. It could have a way of knowing
if the outlet ground is connected to the neutral, but that's
it.
There are two issues. One is if the panel has an earth
ground, which you have now verified. The other is if
the grounds from outlets are in fact connected back
to the panel ground. If you're having problems with
UPS faults about ground, I would suspect that the outlet
does not have a ground path back to the panel.
gregz
Nov 16, 2012, 9:42:28 PM11/16/12
to
place, but the wire to the water ground is 35 feet away.
> While looking for the elusive house ground, I noted that the TV
> antenna we had installed several years ago has a long ground
> wire, but no ground. The wire is just coiled up in the garden
> soil next to the house under the antenna. I guess Job#1 (after
> a call to the installer....) is to run that wire through the
> crawl space and mate it up with a cold water pipe. ??
your house.
Greg
tra...@optonline.net
Nov 17, 2012, 8:05:51 AM11/17/12
to
>
> - Show quoted text -
Says who? Typically an antenna is installed on the roof
> - Show quoted text -
of the house and the ground is run to the single point
grounding system for the house. Where should they run
it to? Afghanistan?
.-.
Nov 17, 2012, 9:19:23 AM11/17/12
to
"bud--" <remove....@isp.com> wrote in message
news:50a648dd$0$27116$c3e8da3$1cbc...@news.astraweb.com...
have thick layers of sandstone about 18 in. below grade (no basement!) and
so made sure that the water and gas piping in the house, now about 10 years
old, is bonded to the copper water supply pipe going to the street. The gas
supply pipe is plastic. The water pipe is buried in a trench about 3 feet
deep chipped out of the rock and back filled with sand and top soil.
The main panel is connected to a ground electrode which the contractor made
by drilling down into the stone and putting in a copper rod. I've checked
for a voltage difference a few times between the panel and the incoming
copper water pipe and it measured zero on the most sensitive setting of the
multi-meter. Probably that's because the top soil is usually moist to wet
since rain water doesn't sink into the sandstone, but slowly moves
horizontally keeping the region around the top soil and stone conductive.
The incoming water pipe and ground electrode are about 15 feet apart with no
direct bond. Should there be one?
Tomsic
bud--
Nov 17, 2012, 9:21:51 AM11/17/12
to
house. That allows the coax shield to be earthed. That connection, in
particular, plus the ground wire from the TV antenna, should connect to
the earthing system near the service panel. During a surge "event" (or a
near lightning strike) the "ground" at the service panel may be
thousands of volts different from 'absolute' earth potential. Much of
the protection is that all wiring in the house - power/TV
antenna/cable/phone/... - rises together. That requires a short wire
from entry protectors to a common connection point on the earthing
system. The distance from the service N-G bond to the common connection
point also has to be short.
bud--
Nov 17, 2012, 10:07:11 AM11/17/12
to
With a plastic supply it shouldn't matter. The way the NEC handles it is
that metal gas pipe is connected to the building ground at appliances,
like gas stoves and furnaces.
>
> The main panel is connected to a ground electrode which the contractor made
> by drilling down into the stone and putting in a copper rod. I've checked
> for a voltage difference a few times between the panel and the incoming
> copper water pipe and it measured zero on the most sensitive setting of the
> multi-meter. Probably that's because the top soil is usually moist to wet
> since rain water doesn't sink into the sandstone, but slowly moves
> horizontally keeping the region around the top soil and stone conductive.
>
> The incoming water pipe and ground electrode are about 15 feet apart with no
> direct bond. Should there be one?
be much anyway).
Not obvious if it is from the description, but the water pipe should
also be used as an earthing electrode. Water pipe and ground rod should
both connect to the service panel neutral-ground bar. They can connect
at the bar, or (if I remember right) the ground rod wire can connect to
the water pipe wire at a convenient point. There should be a bond wire
across the water meter.
My guess is that the resistance to earth is quite high. In a surge
"event" the building "ground" will lift higher above 'absolute' earth
potential than usual. Having short ground wires from entry protectors
(phone, cable, dish, ...) to a common connection point on the earthing
system is more important than most houses. And the distance from the
service N-G bond to the common connection point should also be short.
You want all wiring to rise together.
bob haller
Nov 18, 2012, 12:01:00 AM11/18/12
to
> The incoming water pipe and ground electrode are about 15 feet apart with no
> direct bond. Should there be one?
>
> Tomsic
poor conductors and mayy be removed at some time
(PeteCresswell)
Nov 20, 2012, 3:46:29 PM11/20/12
to
Per bud--:
>That requires a short wire
>from entry protectors to a common connection point on the earthing
>system. The distance from the service N-G bond to the common connection
>point also has to be short.
Is there a conflict there for a TV antenna mounted on the North
end of the house with coax running down the North wall and
entering the crawl space there - and a service panel on the
opposite end of the house?
--
Pete Cresswell
>I agree. There should also be a ground block where the coax enters the
>house. That allows the coax shield to be earthed. That connection, in
>particular, plus the ground wire from the TV antenna, should connect to
>the earthing system near the service panel. ...
>house. That allows the coax shield to be earthed. That connection, in
>particular, plus the ground wire from the TV antenna, should connect to
>That requires a short wire
>from entry protectors to a common connection point on the earthing
>system. The distance from the service N-G bond to the common connection
>point also has to be short.
end of the house with coax running down the North wall and
entering the crawl space there - and a service panel on the
opposite end of the house?
--
Pete Cresswell
tra...@optonline.net
Nov 20, 2012, 4:08:45 PM11/20/12
to
be to have another ground rod on the end of the house
with the antenna and have that ground rod bonded to the ground rod at
the main panel. However there are plenty of houses out there that
just have the antenna ground on one end and the panel grounded on the
other. This common
ground is one reason utilities, ie electric, phone, cable,
etc come in at the same place.
(PeteCresswell)
Nov 21, 2012, 9:46:22 AM11/21/12
to
Per tra...@optonline.net:
sounds like attaching that antenna ground wire to the nearest
cold water pipe would do the trick.
Or would I be trying to electrocute anybody who happened tb using
a faucet at the time of the strike?
--
Pete Cresswell
>In that situation the technically correct thing to do would
>be to have another ground rod on the end of the house
>with the antenna and have that ground rod bonded to the ground rod at
>the main panel. However there are plenty of houses out there that
>just have the antenna ground on one end and the panel grounded on the
>other. This common
>ground is one reason utilities, ie electric, phone, cable,
>etc come in at the same place.
Given that one of the building's grounds is a cold water pipe, it
>be to have another ground rod on the end of the house
>with the antenna and have that ground rod bonded to the ground rod at
>the main panel. However there are plenty of houses out there that
>just have the antenna ground on one end and the panel grounded on the
>other. This common
>ground is one reason utilities, ie electric, phone, cable,
>etc come in at the same place.
sounds like attaching that antenna ground wire to the nearest
cold water pipe would do the trick.
Or would I be trying to electrocute anybody who happened tb using
a faucet at the time of the strike?
--
Pete Cresswell
tra...@optonline.net
Nov 21, 2012, 11:06:24 AM11/21/12
to
an antenna mast up on the roof with a ground wire
that leads back into the house and is connected to
a cold water pipe. Lightning hits the antenna and
where are you asking it to go? Into the house.
Don't know about you, but I'd prefer to keep it out of
the house. And the longer the path from the antenna
to earth ground, the higher the impedance. Also
adding to the impedance are any turns the ground
wire and piping make on their way through the house.
If you have a couple 90 deg, sharp turns where the
ground enters the house on it's way to the water pipe,
there is the distinct possibility that the lightning will
decide there is an easier path to ground and go that
route. For example, it could just arc over to earth
near where it enters the house. Again, I'm sure you
can find plenty of houses where this has been done
with no ill effects.
An interesting alternate method would be to have a
ground rod for the antenna and then use the cold water
pipe to bond it to the main grounding system of the
house. That way with a strike, the vast majority of
the energy is going to go right to earth, not into the
house. By having that ground rod bonded to the other
system via the cold water pipe, it would keep the
ground voltage level close, ie the two will be at
somewhat similar levels. Without it, you could
have the ground reference at the antenna point
thousands of volts different from the main house
ground. And then the TV for example, could get
damaged.
But I don't know if it's kosher to use the cold water
system to do the bonding. I could sleep OK if it
were my house, but technically I suspect something
in the code says you have to run an actual grounding
conductor between the two ground rods. Perhaps
Bud can weigh in on this.
bud--
Nov 21, 2012, 10:23:45 AM11/21/12
to
The NEC wants a 20 ft max ground wire from the coax entry ground block
to the power earthing system. If the wire is over 20 ft the NEC wants a
ground rod near the coax entry point (connected to the entry ground
block) and a #6 min bond wire from that ground rod to the power earthing
system.
During an "event" that rod can be thousands of volts different from the
building 'ground'. Because of the inductance of the bond wire and
relatively high frequency current components of a surge, the bond wire
does not necessarily reduce the voltage to a reasonable level.
IMHO the 20 ft limit is more reasonable for cable, where you have
significant risk of surge entry. There should be little surge risk from
a TV antenna. (The protection in the NEC is not for a direct lightning
strike to the antenna - far more elaborate protection would be required.)
1 I might use a ground wire somewhat longer than 20 ft
2 If a rod is added at the cable entry you could run the coax near the
power service and add a second ground block. (That adds coax length and
signal loss.)
3 Just add a rod and bond wire.
Particularly for 1 and 3 (or leaving it the way it is) a plug-in
protector at the TV would add protection. The coax must run through the
protector. (All external wires go through the protector, and all
interconnected equipment connects to the same protector.)
(PeteCresswell)
Nov 22, 2012, 10:01:30 AM11/22/12
to
Per tra...@optonline.net:
Sounds to me like there is no downside to a dedicated grounding
rod for the antenna - right under it where the ground wire drops
down the side of the house.... and then work out the bonding
possibilities with the rest of the ground system later.
Have I got it right?
--
Pete Cresswell
>An interesting alternate method would be to have a
>ground rod for the antenna and then use the cold water
>pipe to bond it to the main grounding system of the
>house. That way with a strike....
>ground rod for the antenna and then use the cold water
>pipe to bond it to the main grounding system of the
Sounds to me like there is no downside to a dedicated grounding
rod for the antenna - right under it where the ground wire drops
down the side of the house.... and then work out the bonding
possibilities with the rest of the ground system later.
Have I got it right?
--
Pete Cresswell
tra...@optonline.net
Nov 22, 2012, 11:41:20 AM11/22/12
to
happens. And until it is bonded to the house grounding
system, with a lightning strike, you could have that
ground and anything connected to it, ie TV, at possibly
thousands of volts higher than the house ground, thereby
destroying the TV, etc.
However, there are undoubtly a whole lot of houses out
there where it's done with just the antenna grounded
and no bonding. And given how much of a PIA it might
be to run a proper bond, I might not do it myself either.
At the end of the day, with what you describe, you don't
have the perfect situation, but you do have a ground for
the antenna and IMO it's not a big safety issue. More of
an issue that the TV has a higher possibility of getting
zapped.
bud--
Nov 22, 2012, 1:07:09 PM11/22/12
to
through the power earthing system, the rod can be thousands of volts
different from the building "ground". Those thousands of volts can show
up at anything connected to the antenna and power. I wouldn't add a
ground rod without bonding it back to the electrical system. But bonding
does NOT eliminate this problem, created by the distant rod. IMHO the
rod increases the probability of damage.
What the NEC wants now is the power system earthing connection to the
water pipe within 5 ft of where the water pipe enters the house. One of
the places for the rod bond to connect is in the same 5 ft. Years ago
the power system connection could be anywhere on the water pipe. My
preference generally is to connect the rod bond near the power service.
If lightning strikes the antenna, a ground rod will help only a little.
The earth potential at the ground rod will likely be many tens of
thousands of volts different from the building earthing and the building
"ground". The antenna will be even further. There will likely be major
damage. That can include arcing from the antenna or antenna wires to
elsewhere in or on the house.
Ask a ham with a high antenna what you have to do for lightning
protection. Earthing is only part of the protection. A major element is
that all wiring rises to the same potential during a strike. You can't
reliably do that with the distant (but bonded) rod. A start would be to
route the antenna wire into the house adjacent to the power entrance
with the antenna in a compatible location.
For most of us, it is real unlikely our houses (or antennas that don't
stick way above the house) will be hit by lightning, and is not
cost-effective to provide lighting protection.
Some principles:
I isn't easy to make connection to the earth. A ground rod is one of the
worst ways.
Two points of earth that are pretty close together can be many thousands
of volts different during an "event".
The ends of a wire, maybe 20 ft long, can be thousands of volts
different during an "event".
(PeteCresswell)
Nov 22, 2012, 2:04:44 PM11/22/12
to
Per tra...@optonline.net:
Your observation about bonding later never happening rings
true...
--
Pete Cresswell
> More of
>an issue that the TV has a higher possibility of getting
>zapped.
But no higher than now with no ground rod at all, right?
>an issue that the TV has a higher possibility of getting
>zapped.
Your observation about bonding later never happening rings
true...
--
Pete Cresswell
Dean Hoffman
Nov 22, 2012, 4:50:22 PM11/22/12
to
temporary.
tra...@optonline.net
Nov 23, 2012, 12:44:57 PM11/23/12
to
On Nov 22, 4:50 pm, Dean Hoffman <dh0...@inebraska.com> wrote:
> On 11/22/12 1:04 PM, (PeteCresswell) wrote:> Per trad...@optonline.net:
would be lower, not higher.
If it were me, I would rather have the antenna grounded
to a seperate ground rod that is not bonded to the main house
ground, rather than no ground at all. At least you have a
path for the main lightning current to follow and it's not
into the house. In addition to the mast being grounded,
there should be a lightning arrestor installed on the
signal cable.
> On 11/22/12 1:04 PM, (PeteCresswell) wrote:> Per trad...@optonline.net:
> >> More of
> >> an issue that the TV has a higher possibility of getting
> >> zapped.
>
> > But no higher than now with no ground rod at all, right?
Yes, I would think the possiblility of the TV getting zapped
> >> an issue that the TV has a higher possibility of getting
> >> zapped.
>
> > But no higher than now with no ground rod at all, right?
would be lower, not higher.
If it were me, I would rather have the antenna grounded
to a seperate ground rod that is not bonded to the main house
ground, rather than no ground at all. At least you have a
path for the main lightning current to follow and it's not
into the house. In addition to the mast being grounded,
there should be a lightning arrestor installed on the
signal cable.
David Combs
Jan 15, 2013, 1:33:21 AM1/15/13
to
In article <50a648dd$0$27116$c3e8da3$1cbc...@news.astraweb.com>,
bud-- <remove....@isp.com> wrote:
If I wanted to learn more about all this, what
would I read. Preferably something that didn't
simply say what the code demanded, but rather
something that *explained* enough so that
you'd be able to look at various grounding
systems and be able to tell the pros and cons
of each.
Any ideas?
David
bud-- <remove....@isp.com> wrote:
If I wanted to learn more about all this, what
would I read. Preferably something that didn't
simply say what the code demanded, but rather
something that *explained* enough so that
you'd be able to look at various grounding
systems and be able to tell the pros and cons
of each.
Any ideas?
David
k...@attt.bizz
Jan 15, 2013, 1:29:58 PM1/15/13
to
>Any ideas?
Use GFCIs.
bud--
Jan 15, 2013, 1:53:42 PM1/15/13
to
commonly used chapters. I have accumulated information over many years.
The best source may be "Soares book on gounding and bonding" published
by the International Association of Electrical Inspectors. At almost 400
pages it is overkill for most people.
http://ecmweb.com/bonding-amp-grounding/grounding-vs-bonding-part-1-12
is a 12 part series from EC&M magazine (which is very good magazine, or
was when I was reading it). [HeyBub used one page as a source, which had
an error, likely oversimplification that was probably fixed on a later
page. I have not read the whole series.]
I read a book on "grounding" from the library and took strong exception
to several pieces.
You can ask questions here, but sometimes it is hard to know what to ask.
dpb
Jan 15, 2013, 3:15:30 PM1/15/13
to
On 1/15/2013 12:33 AM, David Combs wrote:
get you'll be able to discern "pros and cons" other than what is
outlined for some given situation by any particular author.
An overall practical non-journeyman's guide is
<http://www.amazon.com/Practical-Electrical-Wiring-Residential-Commercial/dp/0971977968>
It's based on given revision of NEC but is written as narrative-style
rather than simply the Code sections and has introductory chapters that
are good for getting concepts for the
neophyte/non-engineer/non-techschool trained...you'll not be ready for
licensing exam but you'll have a good start and have info at hand for
most household/farmstead/_light_ manufacturing that likely to run across
outside actual commercial/industrial applications.
--
=
Jan 15, 2013, 5:31:37 PM1/15/13
to
"dpb" <no...@non.net> wrote in message news:kd4dcm$3eg$1...@speranza.aioe.org...
one:
http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dstripbooks&field-keywords=NEC+2011+Code+Handbook
It's the National Electrical Code word-for-word text with comments,
explanations, examples and lots of pictures.
Tomsic
bob haller
Jan 16, 2013, 6:18:01 PM1/16/13
to
Dont forget to install a ground jumper between the 2 sides of the
water meter, meters dont make good conductors and might be removed at
some time.
And bond all grounds together. otherwise ground loops can occur.
Having grounds at different potentials can cause a hazard if anyone
gets across 2 different potential ones. Nasty shock can occur:(
water meter, meters dont make good conductors and might be removed at
some time.
And bond all grounds together. otherwise ground loops can occur.
Having grounds at different potentials can cause a hazard if anyone
gets across 2 different potential ones. Nasty shock can occur:(
David Combs
Feb 27, 2013, 9:59:41 PM2/27/13
to
In article <d214f812-18a9-43d6...@a15g2000vbf.googlegroups.com>,
Excellent "white paper" on grounding and the neutral-wire here:
http://www.apcmedia.com/salestools/SADE-5TNQYQ/SADE-5TNQYQ_R1_EN.pdf
http://www.apcmedia.com/salestools/SADE-5TNQYQ/SADE-5TNQYQ_R1_EN.pdf
David Combs
Mar 13, 2013, 10:33:13 PM3/13/13
to
In article <kgmh6t$nvc$2...@reader1.panix.com>,
Hey, anyone go look at that stuff?
They have a variety of interesting "white papers" there.
If you have looked at any of it, how about commenting
back here, suggesting that others do or do not go
there themselves.
David
They have a variety of interesting "white papers" there.
If you have looked at any of it, how about commenting
back here, suggesting that others do or do not go
there themselves.
David
0 new messages