installing light fixture with no ground from source - help!
An electrician disconnected the old pendant light and as I went to replace it today realized that there isn't a ground wire from the blue junction box. Can I just connect the ground wire from the fixture to the green screw on the mounting plate and be ok? Also, the previous fixture had a transformer which I can't even begin (although have tried looking it up) how that was all connected....esp. without a ground wire from source. ALSO, since both of the source wires are so well taped up I can't figure out which is white or black....guessing I need to untape and retape once I have it figure out, right?
THe light fixture will work perfectly fine without a ground (The old light fixture worked fine without a ground).
It is not mandatory to rewire that circuit let alone your entire house to install that light fixture.
To find out which wire is the hot wire (and should not be white), do this before installing the light fixture: Turn the power on, flip the switch on, and measure voltage between one loose end and the metal box (or between one loose end and a long wire you have strung from a known ground such as a radiator, across the floor, to where you are working. Repeat for the other wire end up in the ceiling. The one that reads 120 volts is the hot wire and the other is the neutral.
See if there is a bare wire accompanying the two taped wires into the box. If so, this is your ground wire. Connect it to the metal box and also to the ground wire or ground screw of your new fixture using extra short lengths (pigtails) of bare wire and a wire nut if needed.
You can optionally string a permanent ground wire from that fixture to the panel where the breaker for that circuit is located. The wire does not have to follow the exact route of the wires and cables of that circuit back to the panel.
The good conscientious technician or serviceperson will carry extra oils and lubricants in case the new pump did not come with oil or the oil was accidentally spilled, so the service call can be completed without an extra visit.