Howard Winter wrote: > I presume you mean that as it's already like that, you don't have to > change it? (My staircase wouldn't be allowed to be built nowadays, but I > don't have to change it). Yes, that's what "grandfathered" means. > I was appalled to find that when I visited a new friend's house in New > York, that the sockets didn't have earthing, but 2-to-3 pin convertors > were plugged in (often with multi-way extensions connected) with a tiny > earth lead *sometimes* clamped by one of the mounting screws. I went > with her to Home Depot and bought a box of new sockets (Al/Cu compatible > - what is different from Cu-only, I wonder?) and set to replacing the > most important sockets for her. (I wonder if someone is going to say I > shouldn't have done so as I'm not a NYC-acredited electrician? :-) I > take it that it's usual for the steel conduit to form the earth conductor > in these installations? Because there certainly wasn't a wire to do the > job! If you installed 3-wire outlets in the wall without verifying the ground connection, then you created a serious code violation where one didn't exist before! Anyone seeing such an outlet will *assume* that the ground pin is grounded, and if it isn't, a fault in an appliance will create a very dangerous situation instead of tripping the circuit breaker. Even if you see metallic conduit (rigid or flexible) at a particular outlet box, you can't be sure that it's continuous back to the main distribution panel, or even that the panel itself is in fact properly grounded! You should tell your friend to have a competent electrician take a look at the wiring in the house, or to change the outlets back to the 2-wire variety. -- Dave Tweed -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.