OT for a sec: US wiring sources of info

[Chuck Guzis]

On 10/7/2005 at 11:36 AM Ethan Dicks wrote:

>In older houses, I've seen miswired outlets lots of times.  My house
>had two when I moved in , for example.  Most appliances, especially
>lighting fixtures, don't care.  Best to identify and correct, anyway.

When I moved my home, I had a Toshiba microwave oven that refused to operate (would not power up) when installed at the same outlet that had previously powered a Whirlpool unit.  Thinking it might be the outlet, I tried the oven on an extension cord plugged into a different outlet--worked just fine.  I plugged a worklight into the original outlet--no problem.  It dawned on my that there might be a fault in the outlet, but more of a mechanical thing where contact wasn't being made with the Toshiba plug.  After opening up the outlet box, I noted that it had been installed with the wires (black/white)  wires swapped.  On a hunch, I reversed them and reassembled the outlet.  The Toshiba worked fine.

I went around the house and discovered at least 8 more outlets with the same problem.  The house wasn't at all old and was wired by a licensed contractor and subsequently inspected.

Regardless of how your outlet is (or isn't) labeled, it's the side of the outlet that accepts the wider blade that is grounded, along with the long grounding prong.  If I were setting up a conversion from ungrounded 220v to US 120v, I woiuld make my receptacle a GFCI model (ground fault circuit interrupter) model for safety...

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If I remember what my friend from Aylesbury told me aobut UK wiring, it isn't uncommon for a 50 amp 220 volt pair to be run to all outlets; the fuse being in the plug of the appliance.  He also mentioned that, although in theory, each appliance is to be fused according to its current use, the common practice is to install a 13 amp fuse in everything as a replacement.

On older hormes, it isn't uncommon to find that one side of the line has been grounded through a buried cold-water pipe.   However, as mentioned earlier, code requires a separate buried grounding rod.

Cheers,
Chuck