Shocking discovery

Posted by: Eric Barry on 29 December 2001

I live in a approximately 60 unit apartment building in Manhattan in a neighborhood filled with such buildings. It was built before WWII, and has rather poor electricity, I suspect. To wit, many of the outlets are not three-prong.

The room where I have my hi-fi has two outlets, one normal set with no grounding plug, and one that looks to have been put in specifically for an air conditioner, which has nothing else on the circuit. I have been using this outlet for my hi-fi (CD5, turntable, 72/hi/250) since I have lived here (4.5 years). Today, I returned from a week away and since my hi-fi had not been on, I decided this would be a good time to look at the outlet and clean the contacts.

What I discovered is that though the outlet has three prongs and is rated 15A, there are only two wires connected to it. There is no wire connecting to the terminal for the round pin, which I assume is ground. Thus for this entire time I have been running my system ungrounded, though on a dedicated circuit.

So I have some questions:

1)What are pros and cons of running a ground wire from the outlet to a radiator. Is it possible or likely that the radiator would ultimately connect to PVC pipes and thus not provide a ground? What are the risks?

2)Is it possible the service in my building doesn't provide grounding at all? Everything goes through a fuse box.

3)What are my other options? Should I just have an electrician come in an run a ground wire?

Thanks for your aid and happy new year to all,

--Eri

Posted on: 30 December 2001 by Mike Hanson

Ultimately, it's "wrong" as it is. As long your equipment doesn't have a fault (e.g. one of the live wires comes in contact with the exterior case), then this isn't a huge deal. It will certainly affect your RFI interference, though.

BTW, "ground" is called "ground", because it's usually the earth (that big ball we live on). However, a ground can be almost any large repository for stray electrons. Therefore, if you cannot get a true ground, you're probably better to connect it to the radiator (even if it's not truly grounded itself), since the "repository" would be larger than it is now.

Another thing you should do is contact your building management to see what they suggest. Maybe they'll rewire your apartment, or perhaps they'll try to evict you for being a squeaky wheel.

-=> Mike Hanson <=-

Posted on: 30 December 2001 by Paul Ranson

quote:
Therefore, if you cannot get a true ground, you're probably better to connect it to the radiator (even if it's not truly grounded itself), since the "repository" would be larger than it is now.

I think this is an extremely bad idea, in the event of a fault your entire central heating system becomes live rather than just the equipment.... (Not to mention the heating of all your neighbours!)

Paul

Posted on: 30 December 2001 by garyi

Would be nice and warm though eh?

Posted on: 30 December 2001 by Justin

Building codes in most areas require that three pronged outlets be grounded. Technically, your three pronged, ungrounded outlet is not up to code as it is (giving the impression of ground when there is none). Depending on how vigilent your superintendant is, upon concluding that the outlet cannot be grounded, he may require you to put a two pronged outlet back in.

Judd

Posted on: 30 December 2001 by Eric Barry

First of all, the maintenance here is very sloppy. Second, I think that buildings are required to use three prong outlets these days, but I could be wrong. Is it standard for old wiring to just have wire for hot and neutral? If I go popping outlets off, am I likely to find that even the ones that have had a three prong outlet put in are not grounded? Is it possible that the service to the apartment is ungrounded?

--Eric

Posted on: 30 December 2001 by Phil Barry

IIRC (from experience installing 3-pronged outlets), the ground input hole and the neutral input hole are connected in 3-prong outlets; therefore, there is a return to ground in your plug. This allows the 3-prongers to be used effectively without rewiring buildings.

I assume that eletricians break the connection or use specially constructed outlets when they run 3 wires.

Mike's thought on speaking to maintenance is funny. Hey, Mike, this is in Manhattan, and not a fancy section. Eric's lucky there is any maintenance at all.

Phil

Posted on: 30 December 2001 by Mike Hanson

quote:
in the event of a fault your entire central heating system becomes live rather than just the equipment

I was just coming back to add that, but you got it for me.

quote:
Hey, Mike, this is in Manhattan, and not a fancy section. Eric's lucky there is any maintenance at all.

Fully understood!

-=> Mike Hanson <=-