2-prong to 3-prong

[chuckferguson]

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Hi, I install home computers, and recently I was in a beautiful old house to install a machine but found there were only two-prong ungrounded outlets. I didn't know what else I could do, so I removed the grounding prongs from a six-splitter and plugged that into the wall. I plugged the computer and the LCD display into the six-splitter. Can someone tell me if this is dangerous and if so how dangerous? Thanks very much. chuck

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[aemeijers]

Dangerous to humans? Probably not much, since computers are mostly plastic these days. Dangerous to the computer- probably to definitely, depending on how house is wired, and how often power goes flakey in that part of town. Did you tell your boss what you did? Did you pull a cover and see if the feed wire had a ground, or perhaps was grounded through metallic conduit? Cure may be as simple as switching the outlet for a grounded one, hooked up properly. A gfci could be installed with the appropriate label as being non-grounded. PROPER cure is to get an electrician in there- if the house wiring is marginal, best cure is to snake a dedicated string back to service panel, just for the computer station. If the people use this computer to make a living, a small UPS box is probably indicated.

-- aem sends...

[Mikepier]

If the entire house has 2 prong outlets. the easiest thing to do would be to install GFI breakers to protect the entire circuit ( except the fridge circuit).

[RBM]

For you, not being an electrician, the most practical thing to do is carry a few grounding adapters like these:

Make your installation using the adapters and instruct the customer to contact their electrician to provide a grounded outlet for the installed equipment.

[Stormin Mormon]

If a power wire inside the computer touches the (metal) case of the computer, the case can become energized. And thus, a shock hazard to the people. With a grounded system, the power goes through the ground wire back to the earth. With the ground prong cut off, the power goes through the person, electrocuting that person.

[Lou]

Explain it to the home owners, let them decide weather to go forward or not, Advise them to contact an electrician, and have them sign a release of liability. You may have just screwed yourself. Lou

[Claude Hopper]

NEVER cut a ground prong! Just get the little gray adapters that convert

3 prong to 2 with a green wire that has a spade lug on it. Plug the power strip into the adapter, connect the adapter green wire to the middle screw on the wall plug. If it's grounded it will be grounded, if it isn't it isn't. Not your problem. Plug the adapter into the 2 prong outlet. Point out to the owners that this is not the best connection but they should be used to it since they must have had to do this all over the house. Check and see how they have their microwave plugged.

[LouB]

BEST reply!!

Lou

[JJ]

macsimize_at_mac_dot [e-mail] (chuckferguson) wrote in news:HjZuk.434$F [e-mail]:

wall. I

That wasn't smart; also really dangerous. Adapters. That's what they're made for. Plug the surge strip into a properly grounded adapter. Most surge strips have a light to tell u if it's grounded anyway.

[gfretwell]

I bet you find the case of that computer is cruising around 60 volts referenced to ground. The line filter in the power supply does that. I found this out with the PC based MP3 players in my cars, running on inverters. If you are hooking this to the existing car audio system you will have an ear shattering hum unless you bond the PC case to the car body.

[misterjustme]

Installing a two prong to three prong adapter (or a "grounding" adapter) is usually the same thing as cutting the ground prong off of a cord; if an equipment grounding conductor was present then a three prong receptacle would have been installed. I have never run across a two prong receptacle installed on a branch circuit that had an equipment grounding conducter present. For those that insist a conduit acts as the equipment grounding conductor; how many homes have conduit installed for branch circuits? The correct course of action would be to install a GFCI receptacle and mark it "No Equipment Ground" or install an equipment grounding conductor. This is beyond the scope of an installer of PC's and you should have made that recomendation.

[AZ Nomad]

An adapter isn't going to provide a ground. All it will do is connect the power strip's ground to the screw of the outlet which won't be grounded.

[Gary H]

Dry skin is unlikely to conduct enough electricity to be dangerous (at

120V). Maybe that applies to the computer you keep by the side of your bathtub.

[AZ Nomad]

Not only that, but power supplies don't connect the mains to the ground. The chance of the ground being anything but high impedance is rather unlikely.

The ground is there for the unlikely chance that a broken wire inside the computer could come in contact with the case and this is extremely rare.

Don't take the computer into the bathtub and there won't be a problem.

[Marilyn & Bob]

Installing a two prong to three prong adapter (or a "grounding" adapter) is usually the same thing as cutting the ground prong off of a cord; if an equipment grounding conductor was present then a three prong receptacle would have been installed. I have never run across a two prong receptacle installed on a branch circuit that had an equipment grounding conducter present. ####

Simply not true. Many units (at least in NYC) built in the 60's had BX wiring with two prong recepticles. A grounding adapter, while far from perfect, would work in those cases.

[DerbyDad03]

Did anybody else notice the first line of this post?

"I install home computers"

For who? Who would send out a technician that knows so little about the power/wiring requirements for the equipment he is charged with installing?

I smell a troll.

[aemeijers]

Same here in MI and in IN where I used to live- from late 50s to mid

60s, grounded romex and boxes with 2-hole outlets was quite common. Made converting the 2-hole outlets in this place easy- just made sure the copper wound around the romex under the clamp was shiny, the clamp was snug, and ground the outlet to the box. Magic outlet meter is happy. Yeah, I know current code regards that as borderline, but I wasn't about to try and unwind that 45 year old copper to run it to the screw on the outlet. It does get brittle. Putting the ground wire under the clamp was SOP by all the electricians when I was growing up watching them. They said it made for a less crowded box.

-- aem sends...

[George]

Best Buy (among others) would. They don't pay very well and get what they pay for. My buddy's son worked for the local one when he graduated from college while he was looking for a real job. The kid is really sharp and went on to get a really good position and a reputable company. He said they got minimal training at BB which mostly consisted of how to push other stuff while they were doing an "expert" installation.

[Michael A. Ball]

Yes. My thought exactly.

________________________ Whatever it takes.

[Michael A. Ball]

Hell's bells! No offense, but I'm surprised you had to ask these questions.

FYI, no surge suppressor or battery backup manufacturer will honor their insurance policy, if the computer isn't properly connected to a properly wired circuit.

I live in a one hundred year old house, which has only a couple of properly wired circuits--and my computer gets one of them!

You asked, "...is this dangerous and if so how dangerous?" If I caught you doing a stunt like you described (and I would catch you), it would be quite dangerous.

DerbyDad03 suspects you of being a troll. I think he might be correct.

_________________________ Zildjian: world class cymbal of excellence.