Good news - looking closely, all the wiring I could see in the sub-basement is in conduit, the panel appears to be grounded, and there are several 3-prong outlets in the level of the house where a family room addition was built. So hopefully things will not be as archaic as I had feared. We’ll get an electrician in to replace the panel, upgrade to 200 amp, give the system a quick once-over and get to town replacing outlets! :eek: (Is this the “shocked” smilie?) 
I bought the family house I grew up in after my parents retired to Fl. They have had it rewired with Circuit breakers as opposed to the old fuse box. It was also moved. I noticed that the outlets are still 2 wire and the Ground for the breaker box is a very heavy maybe 4x O gauge or heavier going across about a room and a half and tied to the main water pipe entry. This doesn’t seem right to me. Any thoughts?
To Sparky and everyone else who believes that mixing ground and neutral wires is a fate similar to death: How do you explain the code-approved use of the ground wire for neutral on 220-volt appliances? Until recent years, all stoves, ranges, etc. were wired this way. Any 110-volt portion of the stove (such as the oven light and the clock) used the ground wire for neutral. And if you buy a new stove to plug into an old (3-wire) 220-volt outlet, you are instructed to connect the neutral to ground. Yes, newly wired houses use 4 wires for 220 volt appliances such as a range, but it’s still acceptable under code to use ground wire for neutral when connecting new appliances to older 3-wire 220 plugs. Wouldn’t this, in your words, “energize the ground”?
Sparky also writes “The neutral bus in your box is grounded so that in case of a short at the panel, it is grounded.” In fact, at least in some boxes, the neutral bus and the ground bus are the SAME bus. Ultimately, all neutral goes to ground. Responses welcomed.
If everything is wired correctly and perfectly functioning, there’s no real hazard. But what happens if something breaks?
Start looking at all of the different failure scenarios. If a hot wire breaks, the thing just stops working. No biggie. But if your appliance uses the neutral as its safety ground, then the case of the appliance is directly connected to neutral. Now, what happens if the neutral gets corroded and breaks? Maybe there was water dripping on the socket since these things are usually in a basement, for example. Your dryer is off, but it probably has some control circuits that are powered by 120 volts, and are therefore connected from one hot to neutral. Only your neutral is busted, so the voltage goes through the control circuitry and energizes the case, and now the case floats up to 120 volts. The current is going to be limited by the impedance of the control circuitry, but it’s still a shock hazard. If you touch the case of the dryer and earth ground (a metal support pole nearby, a piece of plumbing, a sink, etc) then you get shocked.
If, however, your device uses a separate safety ground, if the neutral connection breaks, then the neutral floats up to 120 volts, but nobody really cares because it’s inside the dryer and there’s no chance of you touching it. The dryer case is on a separate ground, and remains grounded.
If you go through all of the different failure scenarios, what you find is that it’s fairly easy to end up with a hot case in the older system that uses the neutral as the safety ground, but you require multiple failures to end up with a hot case with the separate safety ground, which is much less likely to occur.
The separate safety ground is clearly much better.
Is the old way “a fate similar to death”? Well, that’s a bit of an exaggeration. As long as nothing breaks, it’s perfectly safe. But if something breaks, it is more likely to result in a shock hazard, and can potentially kill you.
As for why it is still to code, that’s the way the U.S. electrical code works. If you have older stuff, you don’t have to replace it all every time the code changes. Otherwise most homes throughout the U.S. would require significant rewiring.
This is an old thread, but just for completeness, here’s the answer to this part.
Grounding standards have changed significantly over the years. At some point they required the cold water pipe to be used as an electrical ground, because it made a good ground and pretty much every house had one. Then plastic pipe came along and all of a sudden that reliable metal pipe wasn’t always metal any more, so they changed the standard. In modern homes a separate ground rod has to be used to ground the electrical system. However, you still need all of the water pipes in the house grounded because if you don’t ground them and a hot wire ends up shorting to a water pipe somewhere, then your entire water system becomes a huge shock hazard. So the cold water pipe is still grounded, but it is no longer the primary electrical ground for the house.
There’s no requirement to go back and rewire a house every time the code changes. However, if you change something, the parts that you change all have to be brought up to current code. So when the electrical box was changed out, that all had to be brought up to current code. That means installing a new ground rod and grounding the water pipes at the water service entrance, which is why they had to install a great big long run of thick copper ground wire.
Admittedly it’s a bit silly to have the breaker box brought up to a modern grounding system when all of the outlets are still 2 wire without a safety ground, but the outlets weren’t touched so there’s no requirement to change them to modern 3 pronged outlets with modern 2 conductor plus ground wiring. If you wanted to bring the entire house up to modern code, all of the wiring and the outlets would have to be changed, GFCIs would have to be installed in certain locations (bathroom and garage, typically), and AFCIs would have to be installed on bedroom circuits.
Hello everybody.Bought a 4.9 cubic feet freezer but where I wanna put it, the outlet is a two prong one and has no ground. There are 2 black and two white wires coming out to the outlet no ground wire. Anyway, I was told I could replace it with a GFCI outlet to plug in my freezer or also to run the ground cable from a close grounded outlet to the ungrounded one. Do to want to run wires from main pannel to this outlet. Would rather do one of the first two options mentioned above. Thank u.
So can i ground a two prong ungrounded outlet from a grounded outlet or should I just replace it with a GFCI outlet to plug in my freezer?
putting a freezer on a GFCI circuit might trip the GFCI at some random motor start and leave you with a nonrunning freezer. if the receptacle is just running the freezer then it doesn’t need to be GFCI protected. if other receptacles are used for plugging small things into down strean then the GFCI receptacle can be downstream.
if you can run a grounding wire from another location then run a 3 wire cable with all the wires to that location.