A building has several apartments. Each one has a doorbell, and 4 wires coming to the doorbell. One set is (I assume) for the downstairs main door and the second one is for the door of the apartment.
When I went to replace the old doorbell, the button at the main entry door worked and two wires were connected. The apt. door button didn't work and two wires were disconnected. I couldn't get the apt door bell to work by connecting the two wires to the doorbell at the "rear door" section. In fact one of the wires sparked when I touched it to the terminal.
When I installed the new doorbell, the same thing happened. The entlry door still works when on the "front door" terminal and "transformer", but no joy with the apt door. I put a cheap meter on all four wires to discover which was the transformer wire for each set of two. I got odd readings, something like 50 and 75 volts AC. I figured this was incorrect since the actual voltage should be around 16VAC, and indeed I could touch the wires with no problem.
So what's happening?
Why do I get a higher reading than it should be? Is it because the wires were not connected to anything? Oh, I put the neg test lead into an extension cord on the neutral side (assuming that the plug it was pluged into was wired correctly) and use the pos test lead on the wires coming out of the wall.
What likely caused the arcing when I touched one of the 2nd pair of wires to the doorbell?
Is it likely that the second pair of wires has its own "transformer" lead rather than just taking power from the transformer wire from the first pair?
I assume there's been this problem for a while since the 2nd pair of wires (apt front door) was disconnected. Any way to track down what the problem might be?
Any additional info you need?