Home Improvement → ungrounded wall outlets

I recently moved into an apartment in a 20's era house. Nice apt. with a nice deck and view. It is the electrical that worries me. Some of the wall plugs are two pronged and some are three. My powerbar indicates that none of the three prongs are grounded meaning I guess that the wiring is knob and tube. My question is what are the safety and electrical dangers if any, for my TV and computer equipment. All of these are on powerbars plugged in to the three prongs. I use the two prongs for lamps.

-Bob

What do you mean by power bars?
If they just turn one outlet into more and that is it then ok.
If the device has a third prong you will lose things like case grounding for personal protection. If just a two prong device there will be no change or issues.
Like my wife's kitchenaid has the third prong for case grounding for personal protection that would be lost.

Also depends on the wiring inside the wall and if it is in good condition or deterioration with age.
Other more knowledgeable will reply this is just a start.

Sounds like some moron replaced some outlets without running new wire to them, big no no unless they replace with 2 prong outlets (which are available).

I'd say the whole place needs to be rewired, anytime I've seen 2 prong outlets the wiring behind it has been ALUMINUM!

At minimum I would try to get new outlets installed where properly grounded 3 prongs are needed, like computer and TV areas.

Your concerns about the receptacles are well founded. A three prong outlet w/o a grounding conductor is indeed a life safety hazard and an equipment hazard.
I cannot speak for Canadian electrical code, only NEC. FWIW, CEC closely mirrors the NEC and they are working to merge them.

It doesn't really matter which country you are in, as the systems perform the same. No country can lay exclusive claim to common sense.
Under the NEC, there are a few options.
1) Replace the three prong receptacles with two prong (as they originally were). This makes it impossible to plug in a a device with a grounding plug. An unfortunate side effect is people run out and get "cheater" adapters, making it just as dangerous as before.
2) Replace the three prong receptacles with GFCI receptacles. This method is allowed strictly for life safety. In the case of a ground fault, the receptacle will trip quickly and a crisis will be averted. This will keep a person from being shocked, but does nothing to protect equipment that relies on a true grounding conductor.
3) Install a grounding wire. Either by rewiring the circuit partially or in it's entirety. This is the preferred method. This ensures that any device that requires a true grounding conductor gets it. Many surge protectors, electronics, appliances, and devices that incorporate a grounding plug actually do require a true ground to work reliably and safely.

Unfortunately when you are in a LL situation, they typically are going to have little to no understanding of electricity. They also, quite likely, will be looking to spend the least amount of money possible.
Quite often, that leads to the work being performed by someone who is less than qualified (probably how 3 prong receptacles wound up in there to begin with).

Someone mentioned aluminum. I seriously doubt it. Aluminum wire's heyday was from the late 60's to the late 70's. It also usually had a grounding conductor incorporated in the cable. While it's possible, it's doubtful.
The untrained eye will also confuse older RH wire with tinned copper as aluminum. RH wire was very common in the 20's, 30's, and 40's for K&T, BX (AC) cables, and to a lesser extent - "rag" NM cable.

Yeah, just to confirm, the CEC has the same rule allowing GFCI to replace 2-prong receptacles.

quote:

---

26-700
(8) Notwithstanding Subrule (7), at existing outlets where a grounding means does not exist in the receptacle
enclosure, grounding-type receptacles without a bonding conductor shall be permitted to be installed,
provided that each receptacle is
(a) protected by a ground fault circuit interrupter of the Class A type that is an integral part of this
receptacle;
(b) supplied from a receptacle containing a ground fault circuit interrupter of the Class A type; or
(c) supplied from a circuit protected by a ground fault circuit interrupter of the Class A type.

---

OK, thanks everyone. Not much I can do about this in a tenant landlord situation.

-Bob

1.) You could mention the unsafe situation of ungrounded 3-prong outlets to your landlord. Some do take reported safety issues serious (because of the associated liability for them) and will take steps to improve the situation (which of course includes the possibility that they turn it back into a 2-prong outlet).

2.) You could (at your own expense) replace those outlets with GFCI receptacles which makes them code compliant and safe for the occupants of that apartment (as mentioned before it does nothing for equipment that relies on ground for other purposes).

This is what I have done in rental situations before.

Yes you can. 3-prong receptacles without utility ground conductor was NEVER allowed in the code (so no grandfathering).

You can state that you are aware that there is a hazardous code violation regarding the 3-prong receptacles and inform him of his OBLIGATORY options: 2-prong replacement, or GFCIs or new wiring. Show it as a "favor" that you worry FOR HIM that someone in other units could get shocked/electrocuted (different meanings i know) and he'd be on the line for liability.

Something I've never understood, and maybe someone here can explain to me.
Most people when faced with a 2 pronged outlet will simply buy a "cheater" 3 to 2 prong adapter. Wouldn't just connecting the neutral to ground to safer with a 3 prong outlet? I know it's not allowed, N to G connections, only in the main panel. But I'm just not seeing why this method wouldn't be safer then using one of the 'cheater' adapters. I'm sure there is a reason, and hopefully someone can explain (and no I didn't do this or recommend this, just in my head it seems safer, and no I'm not an electrician or pretend to be either).

Connecting the neutral (grounded conductor) to the ground pin makes it "super extra" dangerous. In the event of an open neutral, any "grounded" parts could become "hot" parts. Any meat sack that happened by and completed the path to ground would be shocked and / or killed.

It's very common for LL's and hacks to do this little "trick" to pass inspection. When you plug in a tester, it appears all is right.

Safety ground is designed to provide a low impedance path to trip the over-current device in case of a fault to normally non-energized part - typically a metal chassis or tool housing.

Think about the ramification of your suggestion. If you tie Neutral and Safety ground together and Neutral ever faults open now those parts are at line potential.

In a dwelling without safety ground the best you can do is use Ground Fault breakers or outlets. They will trip if there is an unbalance between hot and neutral.

/tom

I know someone who has a Yamaha keyboard, a motif 6 long story short his whole thinking of those cheater plugs is crazy.. He plugs his 3 prong cord into the cheater and then it into a 3 prong outlet.. And he says it's grounded..

People I guess don't seem to understand why that tab is on the adapter and where it's meant to go.

I tried to explain but

I'm going to have to think carefully before informing the LL. He's been a friend for decades and gave me a break on the rent for that reason and because he knows I am a not a complainer. He's a lawyer but he has no technical sense whatsoever when it comes to building code or computers. It took me some time to convince him to get a cordless home phone so he wouldn't have to go from sitting in his back yard to into the house to answer his landline. He hates computers and doesn't have one.

I think I'm going to emphasize the GFCI solution and not mention the liability implications of the current electrical situation. Like I said, he's a lawyer so he will understand the liability implications. This house probably contains dozens of wall outlets so even the GFCI solution is going to cost a bundle. I think I'm going to explain that under the current situation if an electronic device develops an internal short the device would become energized thus potentially electrocuting someone (I hope this is correct).

But then again I could just leave things alone. I think I'll wait until next summer when we are sitting in his back yard having a beer when I will bring up the subject casually as a "for your information" item. As you can see I am very wary about rocking the boat.

-Bob

Unless you are a licensed electrician there is no reason to expect you to be aware of a problem with the outlets. I would leave well enough alone. Do not put anything in writing about this matter? But you already did. The following suggestion will solve your concern if you are using appliances with a three prong plug without a properly grounded receptacle. Purchase as many of these GFCI's and adapters you will need:

»www.homedepot.com/webapp ··· 02510241

and one of these for each of the above:

»www.homedepot.com/webapp ··· 00356839

Plug the GFCI into the existing receptacle two prong or three prong and the adapter into the GFCI if the appliance plug is three prong. You are protected.

You might want to warn your land lord friend about the issue because there is the potential of lawsuit if a future tenant is electrocuted.

LL's generally have more responsibility than an average home owner. This is usually brought on through municipal codes.

Asking the LL to correct a potentially dangerous situation isn't whining. It's basically asking him to do his bare minimum job; a job he's obligated to do since he decided to go into the LL business.
If you have a limited understanding of how building systems work, you should always default to professionals for repair and upkeep, hire a management company that is liable, or sell out.

If someone breaks into your house and steals everything, do you call the police? Or, do you just forget about it because you don't want to bother them?

I will go to my local Home Depot and consult with them. The items in the Home Depot links look promising.

I will tell the LL after I find a solution for my TV and computing equipment.

-Bob

Of course, that only works if the box is grounded somewhere, which most K&T boxes aren't.

That little metal strip with the hole? I always cut those off. They just get in the way and no one ever screws them in place anyways.

I'd take an outlet plate off and see what's what behind it. I've replaced several switches in my house (built in '79) where the switch was never grounded, despite having a ground screw. The ground wire from the NM cable was just folded up and sat in the back of the outlet box unused.

My sister's house also had several outlet boxes where the outlets were 2 plugs, but there was a grounding wire clipped to the metal box. There was no reason that a grounded outlet couldn't have been installed.

Oh, halfassing jobs... I had something similar a couple years ago when my mom inherited my grandma's house. I went to install GFCI's and change out a couple "loose" outlets, and came to find that 90% of the 3 prong outlets were not grounded, even though every box had proper grounding wires in them (the ground was not hooked into the boxes either). Only ones with the ground hooked up to the plugs was at the end of a circuit. House was built in 1966.

So, a quick job turned into redoing every outlet and switch in the entire house, which honestly wasn't in vain since I found some aging backstabbed connections (grandma did complain of flickering but never wanted me to fix it). At least all the wire was copper!

1966 House.
A lot of things were only copper
Drain stacks, water pipes, you name it! COPPER GOLD MINE!

However, you got unlucky that a 1966 has no ground for the receptacles. My 1964 house was wired with copper romex with ground.

My last house was built in '61. It had copper romex with ground to each outlet box -- but not the outlets themselves.

I replaced all those receptacles with 3-prong ones and a pigtail to the box ground. I was so glad that the ground was actually there .... Made the 2-to-3 prong upgrade cake.

Cast iron water pipes, sadly. Those were abandoned for aquapex a few years ago. If it was copper I'd be crawling under there and removing what was left!

The ground for the receptacles is there and functioning, it was that when the original electrician who wired the house never bothered to pigtail from the bare grounds in the receptacle boxes to the 3 prong outlets or to the box itself. So for years, most of the things that were thought to be grounded weren't. Definitely not legal now to do that, and, I have doubts that it was legal to that in 1966.

Looks like we both got lucky to not have to rewire!