Question about grounding laws

[bobbintb]

I live in Pocatello Idaho and am an IT professional. I'm not much of an electrician per say but it is an important part of my job, as bad wiring can wreck havoc on expensive server equiptment. Anyway, the city uses NEC 2008 at the moment. This building I'm working at is a residential one. It was built in the 1920's I believe but am not sure. Around that time. Most of the outlets are three pronged but the downstairs has a room where most are two pronged. Now I've checked every outlet in the building and none of them are grounded. This property is a rental and before I approach the owner about the issue I needed to know what the law says. I was told that it might be worth looking into to see how legal it was to have a three prong outlet that is not grounded. I would imagine the outlets were replaced since not all have been changed and I know the house was built before this was a requirement. So, is it legal for those outlets to be altered to three prong without upgrading the wiring?

 

[charlie b]

What the 2008 NEC says is that if you replace a 2-prong receptacle that does not have a ground wire nearby, then you have to do one of three things:
1. Replace it with another 2-prong receptacle.
2. Replace it with a GFCI protected receptacle, and mark it with the text, "No Equipment Ground."
3. Replace with with a 3-prong receptable that is protected by an upstream GFCI device, and mark it with the text, "GFCI Protected - No Equipment Ground."

I don't know when that rule came into being. If a 2-prong receptacle had been replaced with a 3-prong receptacle before that rule came into being, it is possible that the present installation is "grandfathered."

 

[augie47]

If two wire outlets were Code when installed, I know of no locations that require they be upgraded. The NEC provides for methods of grounding a 3 wire receptacle when used to replace a two wire (250.130), or replacing the two wire receptacle with a 3 wire GFCI (406.3), or replacing the two wire receptacle with a 3 wire receptacle that is GFCI Protected (406.3)

(typing as Charlie answered but I think we said the same thing)

 

[K8MHZ]

I would also like to point out that a plug in tester cannot be used to determine if a 3 wire receptacle fed by two wires is GFCI protected or not, unless you make some provision for your tester to be grounded.

Since the yolks of standard receptacles are bonded to the third prong, all that needs to be done is to run a grounded wire to the cover screw. I use a long piece of wire with a ring terminal at one end and a clip at the other. In older structures where the water pipes are all metal, connecting to a faucet or a pipe usually works. Sometimes there is no other way but to go back to the panel with your clip.

The jumper I described above is also great for locating bad neutrals.

 

[Volta]

Just looking quickly, in 1959 it was required to ground grounding type receptacles:

Where a grounding receptacle is installed as specified in Sections 210-22(b) and 250-59, to provide grounding facilities required in Section 250-45, the branch circuit or branch circuit raceway shall include or provide a grounding conductor to which the grounding contacts of the grounding receptacle shall be connected. The metal armor of armored cable or a metallic raceway is acceptable as a grounding conductor.

 

[stew]

k8mhz if you are suggesting running a jumper from the neutral to the cover screw you have violated the code. The section of code that applies to no other neutral paths as in a sub panel applies here as well. heaven help the guy that plugs in a lamp to one of the outlets and is grounded and touches the bare screw on the device plate. With the load enegized you now have the return path of the circuit connected to any and all metallic items exposed to you. My boss has been ding this for years to fake out the testing device plug ins. It apparently will show as a normal outlet when this is done when in fact a dangerous potential situation has been created.

 

[Nium]

k8mhz if you are suggesting running a jumper from the neutral to the cover screw you have violated the code. The section of code that applies to no other neutral paths as in a sub panel applies here as well. heaven help the guy that plugs in a lamp to one of the outlets and is grounded and touches the bare screw on the device plate. With the load enegized you now have the return path of the circuit connected to any and all metallic items exposed to you. My boss has been ding this for years to fake out the testing device plug ins. It apparently will show as a normal outlet when this is done when in fact a dangerous potential situation has been created.

Didn't read k8mhz post to well did ya :grin: ? The jumper suggested is a test lead for getting a 3 prong tester to trip a GFI receptacle because without a ground a 3 prong tester won't trip a GFI rec where the test button on the rec will.

 

[stew]

thats why i used the verbage i did. IF is the operative word in my reply. And yes I read the post but did not quite undestand exactly what the poster was getting at.A tester will of course work with this arraingement but the permanenet neutral jumper is of course a no-no.