I have a US house built in 1958 that has been remodeled in many stages over the years. I recently tested a circuit that included ungrounded outlets in the old part of the house. A number of years ago, we remodeled a bathroom and had the electrician replace a couple of ungrounded outlets on that circuit with what were supposedly grounded outlets (with a GFCI thrown in). I checked both those outlets and there is a ground wire connected to the outlet and going into the wall.
My Sperry (plug-in) tester shows an open ground. Do these testers always show an open ground when a circuit doesn't have a ground back to the panel?
Another couple of notes/questions:
- On one outlet, my Sperry non-contact tester lights up when I get close to it. This works as expected on other outlets (on other circuits). When I pull that outlet out of the wall and test the neutral and hot wires, hot lights up (as expected), neutral does not. Does this indicate a problem with that particular outlet unit or just the general unreliability of non-contact testers? My tester had the same result with two different outlets hooked up to these wires.
- Going back to those "grounded" outlets mentioned above, a multimeter shows about 116V across hot/neutral, but zero from neutral/ground and hot/ground. That seems to indicate that despite the presence of a ground wire, that ground doesn't appear to actually be connected to anything. Is that a reasonable conclusion?