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Home > Archive > Electrical Engineering > June 2006 > How to check house wiring for proper ground?
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How to check house wiring for proper ground?
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| Adam Corolla 2006-06-06, 6:21 pm |
| I know next to nothing about house electrical systems, and I am wondering if
there is an easy way for a novice to check for proper ground. I am in the
US so this is 120v. My unit (townhouse/row house) was built in 2000, and
there are rumors that the company who built the complex cut corners, though
it's probably just a rumor.
Back-story: A lightning strike blew out the boards on my AC, garage door
opener, thermostat, and a few other things. I was looking into getting a
whole-house surge protector in addition to separate ones for the most
expensive electronic stuff, and a friend asked me if maybe my place isn't
grounded properly.
Is there anything I can do or buy that will allow me to easily check my
house wiring?
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| Beachcomber 2006-06-06, 8:21 pm |
| On Tue, 6 Jun 2006 16:05:12 -0500, "Adam Corolla"
<nospam@nospam03550265902.com> wrote:
>I know next to nothing about house electrical systems, and I am wondering if
>there is an easy way for a novice to check for proper ground. I am in the
>US so this is 120v. My unit (townhouse/row house) was built in 2000, and
>there are rumors that the company who built the complex cut corners, though
>it's probably just a rumor.
>
>Back-story: A lightning strike blew out the boards on my AC, garage door
>opener, thermostat, and a few other things. I was looking into getting a
>whole-house surge protector in addition to separate ones for the most
>expensive electronic stuff, and a friend asked me if maybe my place isn't
>grounded properly.
>
>Is there anything I can do or buy that will allow me to easily check my
>house wiring?
>
>
Without fairly expensive, specialized equipment, you won't be able to
do elaborate tests, such as the true electrical resistance of your
ground.
The good news is however, with a simple electrical tester, you can at
least check for ground continuity at each outlet. There are
inexpensive outlet testers that plug in and with lights, give you a
visual indication if the ground is present. They will also reveal
the most common wiring errors.
The old neon bulb testers with the pigtail leads will also work. You
should get a light from HOT to NEUTRAL, (the two flat slot
connections) and from HOT to GROUND (the smaller flat slot connector
and the round hole, respectively).
If you have wiring errors, you might have a light from NEUTRAL to
GROUND.
Do you have GFCI outlets in your bathroom or kitchen? Pushing the
test button occasionaly will perform a safety check on the ground
connections. The outlet should trip off and then you must hit the
reset button.
Beachcomber
| |
| w_tom 2006-06-07, 11:21 am |
| Those little outlet testers will do nothing to verify earth ground.
Earth ground (not safety ground inside building) is essential for
lightning protection. Only way to confirm earthing (short of some very
expensive equipment) is visual inspection.
All incoming utilities should make a less than 10 foot connection to
the single point earthing electrode. A 6 AWG bare copper wire exits
breaker box to connect to this rod. Rod must be secure (cannot be
shaken) and must be at least eight feet in earth. Some contractors cut
costs by cutting a rod in half to use two four foot rods in two
locations.
Telephone and cable also must make a less than 10 foot wire
connection to this earthing electrode. Telephone would already have a
'whole house' protector inside that gray NID box. But the protector is
only as good as its earth ground which is why that grey box connects
'less than 10 feet' to earthing.
Cable requires no protector. Cable must drop down and connect
directly to earthing by a wire.
You can enhance building earthing or verify ground rod is
sufficiently long by installing another. Locate a spot about 6 feet or
more from the existing rod. Drive that new rod into earth. Connection
those two rods together with buried, bare, solid copper wire and some
clamps. Now you have minimally acceptable earthing and are ready to
install a 'whole house' protector.
Wiring inside the house has nothing to do with effective transient
protection - transistor safety. If earthing transients from plug-in
protectors, then transient on safety ground wire only induces
transients on all other wires. Plug-in protectors cost tens of times
more money per protected appliance. Money better spent enhancing the
earthing system and installing a 'whole house protector with more
joules.
A three light tester can report defective internal wiring, but cannot
report that wiring as good or sufficient for human safety.
Adam Corolla wrote:
> I know next to nothing about house electrical systems, and I am wondering if
> there is an easy way for a novice to check for proper ground. I am in the
> US so this is 120v. My unit (townhouse/row house) was built in 2000, and
> there are rumors that the company who built the complex cut corners, though
> it's probably just a rumor.
>
> Back-story: A lightning strike blew out the boards on my AC, garage door
> opener, thermostat, and a few other things. I was looking into getting a
> whole-house surge protector in addition to separate ones for the most
> expensive electronic stuff, and a friend asked me if maybe my place isn't
> grounded properly.
>
> Is there anything I can do or buy that will allow me to easily check my
> house wiring?
| |
| Adam Corolla 2006-06-07, 5:21 pm |
|
"w_tom" <w_tom1@usa.net> wrote in message
news:1149689474.347043.12960@i39g2000cwa.googlegroups.com...
> Those little outlet testers will do nothing to verify earth ground.
> Earth ground (not safety ground inside building) is essential for
> lightning protection. Only way to confirm earthing (short of some very
> expensive equipment) is visual inspection.
>
> All incoming utilities should make a less than 10 foot connection to
> the single point earthing electrode. A 6 AWG bare copper wire exits
> breaker box to connect to this rod. Rod must be secure (cannot be
> shaken) and must be at least eight feet in earth. Some contractors cut
> costs by cutting a rod in half to use two four foot rods in two
> locations.
>
> Telephone and cable also must make a less than 10 foot wire
> connection to this earthing electrode. Telephone would already have a
> 'whole house' protector inside that gray NID box. But the protector is
> only as good as its earth ground which is why that grey box connects
> 'less than 10 feet' to earthing.
>
> Cable requires no protector. Cable must drop down and connect
> directly to earthing by a wire.
>
> You can enhance building earthing or verify ground rod is
> sufficiently long by installing another. Locate a spot about 6 feet or
> more from the existing rod. Drive that new rod into earth. Connection
> those two rods together with buried, bare, solid copper wire and some
> clamps. Now you have minimally acceptable earthing and are ready to
> install a 'whole house' protector.
>
> Wiring inside the house has nothing to do with effective transient
> protection - transistor safety. If earthing transients from plug-in
> protectors, then transient on safety ground wire only induces
> transients on all other wires. Plug-in protectors cost tens of times
> more money per protected appliance. Money better spent enhancing the
> earthing system and installing a 'whole house protector with more
> joules.
>
> A three light tester can report defective internal wiring, but cannot
> report that wiring as good or sufficient for human safety.
>
> Adam Corolla wrote:
>
Thank you!
| |
| Bob Weiss 2006-06-08, 10:21 pm |
| Beachcomber wrote:
>
> Do you have GFCI outlets in your bathroom or kitchen? Pushing the
> test button occasionaly will perform a safety check on the ground
> connections. The outlet should trip off and then you must hit the
> reset button.
>
The self-test function on a GFCI will function perfectly even without a
ground connection to the device. Relying on this as a test of grounding
integrity is a very dangerous thing to advocate...
Bob Weiss N2IXK
| |
| Line Monster 2006-06-09, 2:21 pm |
| Your Townhouse Group should spring for Lightening Arresters throughout
if the Danger Prevails...
on a different note: Your Utility Company may check that your Grounding
Rods and outside electrical system is all properly constructed and still
in place with a few calls or signed petitions from all the
residents..... it concerns them.
| |
| Adam Corolla 2006-06-09, 2:21 pm |
|
"Bob Weiss" <bob.weiss@verizon.net> wrote in message
news:5W3ig.8651$PY6.1051@trnddc05...
> Beachcomber wrote:
>
>
> The self-test function on a GFCI will function perfectly even without a
> ground connection to the device. Relying on this as a test of grounding
> integrity is a very dangerous thing to advocate...
>
> Bob Weiss N2IXK
ODD! I can't see Beachcomber's post, and several other people's posts which
have been quoted here. My killfile list is very small and only has a few
troublemakers from other newsgroups in it, so it must be that my news server
isn't picking them up.
| |
| Adam Corolla 2006-06-10, 10:21 am |
|
"Line Monster" <Kumano@webtv.net> wrote in message
news:24936-4489A338-295@storefull-3253.bay.webtv.net...
> Your Townhouse Group should spring for Lightening Arresters throughout
> if the Danger Prevails...
>
> on a different note: Your Utility Company may check that your Grounding
> Rods and outside electrical system is all properly constructed and still
> in place with a few calls or signed petitions from all the
> residents..... it concerns them.
>
Excellent idea, thank you!
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> US so this is 120v. My unit (townhouse/row house) was built in 2000,
Dont you have some sort of Building gaurantees. In the UK all new
buildings have 10 Year NHSBC certificates. Any problems with somthing
like this would be covered.
Also if you no nothing about electrics my suggestion would be to call
out an electrcian with relevent qualifications. If you tamper with your
electrics and your house burns down your home insurence policy may
become invalid.
| |
| Adam Corolla 2006-06-12, 9:21 pm |
|
"Guido" <Guy.Parkinson@googlemail.com> wrote in message
news:1150127534.995860.79550@j55g2000cwa.googlegroups.com...
>
>
>
> Dont you have some sort of Building gaurantees. In the UK all new
> buildings have 10 Year NHSBC certificates. Any problems with somthing
> like this would be covered.
That must be, I will check with the county and/or state.
>
> Also if you no nothing about electrics my suggestion would be to call
> out an electrcian with relevent qualifications. If you tamper with your
> electrics and your house burns down your home insurence policy may
> become invalid.
Good point! I know just a little more than nothing about electrics, but
more than enough to stay away from house wiring.
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