I need to upgrade my home electricity - I have a home built in 1946. I
don't have any grounded outlets, and most all are only 2 prong.
What are my options? Do I have to put a ground rod in (sounds hard)?
I'd like to have all 3 prong grounded outlets.
Your electrical system has to be grounded already. If it isn't, you have
worse problems than not having grounded outlets.
Why do you want a ground?
Have you checked to see if a ground is available at the outlet, perhaps via
If the house was built in 1946, there is a possibility that the service
was not grounded..
The house that I am renting was built during that time, and did not have
a grounded service until the service entrance was replaced last year when
rain gutters were added following a roof replacement.
-- Welcome My Son, Welcome To The Machine --
Bob Vaughan | techie @ tantivy.net |
First decide what your objective is. For example, wall
receptacles are grounded firstmost for human safety. That
safety grounding also accomplishes other lesser functions.
But other, less expensive methods can provide same human
safety. Earthing the electric panel is both for human safety
AND for transistor safety. This being different from
grounding of wall receptacles. And there is no alternative to
Converting all wall receptacles to 3 wire is a massive
undertaking - typically rewiring the house. Earthing the
breaker box is a minor job that should be installed
everywhere. Those are two different types of grounding. Both
are part of a human safety system. And both also have
different functions. First define your strategic objectives.
Then your question can be better answered. Why are you
grounding? What problems, current and future, do you want to
It is probably a good idea to consider three wire outlets in
the kitchen since 1946 kitchen wire is, by today's standards,
undersized. But again, first you must define the problem to
And for "person safety", as a minimum you should replace the kitchen
outlets with GFCI ones asap, labeled as "Unconnected Ground" if as you
say you have no grounds available in their boxes. That'll prevent
someone from getting electrocuted by an appliance with an insulation
fault if they touch it and a water faucet at the same time. (DON'T use a
GFCI on the refrigerator outlet.)
You mean you already have *some* 3 prong outlets with no ground
connected to them? If you do, you really should label them as
As someone else mentioned, "BX" armored cable was being used in homes
back then, and if your home is wired with it, you *may* be able to
distribute grounds to all your outlets through the steel armor of that
cable, but a check with your local electrical inspector would be in
order before doing that.
How many 3 prong appliances do you have ?
You may not need 3-prong outlets
except in the kitchen ( fridge )
and the laundry room ( washer/dryer )
Get 2-prong polarized outlets for the other room,
and be sure they're wired with "wide blade" = neutral
It will run about $2-3K to get your panel upgraded to 100amp service,
which will include a new ground rod (if needed), as well as a ground
connection where the water service comes in (req by code).
That is best done by a pro, as permits and such may be required, not to
mention just being a good idea.
Then you can run as needed new circuits. For example, you probably
don't need grounded outlets in the living room for lamps, since they
have 2 prong plugs. You should run nice new 3 prong grounded circuits
where you want to plug in a/v equipment and computers.
Get an electrician in for a quote on the service panel upgrade, and ask
a lot of questions.
I believe my panel has already been upgraded to 100amps. I was under
the impression that i need to 'ground' *every* outlet in my house.
Probably by installing a ground rod that attaches to the panel, and
then a ground wire from the panel out to an outlet.
Am i high?
If your panel is properly installed, it will already have a connection
to ground, usually where the water supply (metal pipe) comes into the
house. Look for a thin piece of BX that has only one wire in it, it
will run over to the piping, where it is clamped on. This is the code's
requirement for grounding.
The ground on the outlets needs to be connected to the panel metal box,
this has been done in the past by the metal covering of the wire (BX) or
the metal pipe (conduit) the wires are run in, and the metal outlet box.
Unless you are plugging in appliances with 3 conductor cords, you don't
"need" a 3 prong outlet.
You only need to drive a ground rod if the wires in you house come in
more than like 10 ft away from where the panel is. And all of these need
to be bonded (connected) together with any other ground connection like
at the water service.
As noted previously, earth ground and safety ground are two
different grounds required by the National Electrical Code
(NEC). A connection to water pipe is no longer sufficient to
earth an AC electric system. That connection to water pipe
remains to remove elecricity from water pipes. Never make a
connection to water pipes to dump electricity into those
pipes. This being so important for human safety especially in
bath, shower, and sinks.
Current code calls for a dedicated earthing connection. To
exceed code requirements, that earthing connection must be as
short as possible, no sharp bends, no splices, not bundled
with other non-earthing wires, and the ground must be shared
by all incoming utilities. That means each the CATV wire must
drop down to connect to that single point ground before rising
back up to enter the building. This paragraph only discussing
Volts500 has provided a good summary of household grounding
for human safety, in the newsgroup alt.home.repair entitled
"Grounding Rod Info" on 12 July 2003 at
A recent discussion in the newsgroup alt.home.repair was
"Easiest way to ground a computer" from 5 May thru 10 May
The only place I would most want three wire outlets is in
the kitchen. Especially a dedicated outlet to the
refrigerator that cannot be on a GFCI, must be on its own
circuit, and that must have a three prong outlet. Kitchen
counter tops and things like the garbage disposal, electric
stove and oven, etc all do need that third wire safety
ground. Elsewhere in kitchens, bathrooms, outside outlets etc
can be GFCIed. Also required now is that all bedroom outlets
be AFGIed. Same should be installed on any interior
receptacle that lights a 'live' Christmas tree. These provide
safety not made available with three prong outlets. This
paragraph about making power wall receptacles for human
If running interconnected electronic appliances, then either
all should run on safety grounded three prong outlets OR all
must connect to a power strip so that equipment grounds share
a single point connection. For example, computer, its
external modem, and its printer should somehow share a common
equipment ground. This paragraph more about equipment
grounding for transistor safety.
The electricity isn't different, but the water pipe may be..
I did a panel replacment/upgrade in my house a couple of years ago and asked
the inspector. He said a lot of water systems aren't using copper pipe as
much. The piece of copper coming into your house may be only be a few feet
long before it's connected to plastic.
And, if the city pipes are still metal, they may be using an "impressed
current" cathodic protection system on them and installed an
electrically insulating pipe coupling where their pipe ends and yours
begins, to avoid "shorting out" the impressed voltage on their pipes to
your electrical system's ground. That was a pretty common technique with
gas pipes in some areas too.
Some info on impressed current protection is found in:
First thing that changed is plastic pipe. A plumber need
not worry about electricity nor risk electrocution when
working on pipes while standing in water. Second, other
functions of the earthing system (beyond the NEC's primary
purpose) demand an earthing ground connection be short.
Connections to water pipes often are well beyond 10 feet. If
the code ever fully addresses transistor safety, then earthing
requirements would be further enhanced - significantly.
Easily accomplished if installed when a house is first
constructed. We still don't ground as if the transistor
These solutions (and solutions for the future) can only be
accomplished using a dedicated ground. A ground that a plumber
will not compromise.
Ground problems created by plastic pipe are not just limited
to the earthing ground. Some jurisdictions now require a 6
AWG safety ground wire connected directly from bathtub to
breaker box IF the bathtub is metallic. Again, a problem
created by plastic pipes and by plumbers who need not know
anything about electricity.
Vic Dura wrote:
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