open ground

[deejal]

Some of my outlets have an open ground. Is this dangerous?
When my carpets were cleaned and while still damp, I was moving my computer back into it's place and there was a little tingle on my finger tips. When the carpet dried, I touched the metal portion of my computer casing and there was no tingle.

When I was replacing the outside halogen floodlight, I was holding onto the flood light unit itself while standing on a metal ladder and I got that same little tingle. The tingle is very similar to a 9-volt battery being placed against your tongue.

There is a ground wire running from my circuit panel to my main water line and into the basement floor.

[volts]

deejal: A ground is a safety feature which must bond all metallic devices. Check the integrity of your service entrance ground connection. Make sure suspect outlets have the third (bare or green) wire in each feed cable (from the Romex, BX, etc.) connected securely in the outlet box. If the box is plastic, the ground wire must tie to the device directly. A ground, i.e., a bond connection, ensures that a faulty device will return a fault current directly to the system ground rather than through your body. A tingle as you describe implies that the bond is somewhat questionable.

[kactuskid]

You don't say how old your home is, but if it's an older home it's possible that 3 prong receptacles were installed and if no ground was present then they should really be 2 prong only. Here is a link describing how to test for a ground and what your options are.

http://www.codecheck.com/250_50_commentary.html

[deejal]

quote:Originally posted by kactuskid

You don't say how old your home is, but if it's an older home it's possible that 3 prong receptacles were installed and if no ground was present then they should really be 2 prong only. Here is a link describing how to test for a ground and what your options are.

http://www.codecheck.com/250_50_commentary.html

My home is 127 years old with updated wiring.

[VR6]

is it necessary to have a grounded outlet?

is it dangerous NOT to have it?

Thanks,
VR6

[kactuskid]

It's only dangerous if you're using power tools that are not insulated or it could be dangerous to your computer equipement. Otherwise there's lot's of older systems that use ungrounded receptacles and are fine. Here's a link that'll give you a few more details:

http://www.wallyvision.com/Tech_Info/importance_of_electrical_groundi.htm

[Rewired]

What wouldn't be a bad idea either if the wiring to the outlets does not contain a ground is to put in or have the offending outlets protected by a GFI. That way if a fault occurs, and someone becomes the "path to ground" the GFI will trip open and hopefully prevent someone from getting severely injured. The potential still does exist but there will be that little "safety" that should cut the power off.

A.D

[kactuskid]

Great idea Rewired, GFCIs can be used in most places and do provide that bit more protection.

[Rewired]

[HayZee518]

Check that ground wire running into the basement floor. What may appear to be connected may not be! I have run into situations where a wire goes into the slab as if continuous only to find that the cable eroded right at where it goes into the concrete and is in fact open - no connection to the rest of the ground circuit. The ground is supposed to be at zero potential, this was not! It had a voltage on it and was able to "blow" a 6 amp fuse put in series with the connection.

[LazyPup]

Although it was common in years past to ground electrical service panels and devices to the water pipes, that is now a major no no in the plumbing code, and i think in the National Electrical Code as well. If your service is grounded to the water pipes you might begin by having an approved ground rod installed. In the interim, check your water meter location. Many new meters have dielectic fitting and plastic internal parts that render then insulators rather than conductors of electric. There is suppoesd to be a copper ground wire attached to the main water pipe on the street side of the meter, bridging across the water meter and is attached to the water line on the house side of the meter. The purpose of that bonding wire is to insure an electrical ground in the event the meter is removed or replaced with a non-conductive meter. (In years past many water meter installers were electrocuted when removing meters.) One of the biggest problems occuring today results from the old galvanized iron main wter lines being replaced with plastics. While the plastics do have a greater service life and less problems associated with corrosion they do not conduct electricity, therefore, if your house was previously grounded to the water main, and if that main were replaced with plastic, you now have no effective ground on your electrical system. For the overall safety of both your electrical and plumbing system the simple solution is to have a qualified electrician properly install a driven ground rod, and if your home is plumbed with copper tubing have the electrician bond the copper piping to the driven grounding system. Even though you may not have any electrical boxes or devices grounded to you water pipes, there still remains many other sources of electricity that could energize your pipes, example, a faulty electric water heater, faulty pumps, blowers or other components in a steam or hydronic heating system, faulty water softeners, garbage disposals etc.

[Rewired]

If there is ANY large current flowing through your service ground at any "normal" time a problem exists! In the past I have seen the neutral connection at the top of the meter stack "open" because of a bad connection and the neutral current actually flow through the ground wire in order to return to the poletop transformer. Yet again, I have also been in a house, where the mains were OFF, NO POWER IN THE HOUSE WHATSOEVER and I was getting 4 amps coming OUT of the ground connection, into the neutral and back to the transformer!! (This house was first and closest to the transformer on the pole)..
Be careful in whatever you do, make sure everything is good and tight, and wherever you must use "water pipe ground clamps".. DO NOT use those die-cast ones, spent the extra $$ and get the brass ones!! They will save you problems down the road!

A.D