So, next in my quest to evaluate the health of my new home's electrical system, and call in professionals if needed, was some voltage checking of the panels/outlets around the house. What I have is a main 200A service in the basement, and a 100amp sub-panel on the main floor. See the attached schematic (notice the main panel has a bonding strap between neutral and ground, where as the sub panel does not- I believe this is the right way for it to be wired).
I borrowed a friends Fluke multimeter and found the following- In both panels, the red bar to neutral is 119 volts, and the black bar to neutral is 121.5 volts (red and black in my diagram). Testing the outlets around upstairs, I noticed that, as expected, some have a delta v of 119, others, 121.5. I then tested the voltage drop across red to black, and found it to be around 242 volts. I also noticed that I have a slight voltage across my neutral to ground (it just so happens to be about 1.5 volts) upstairs.
Is this kind of small asymmetry normal? Should I be getting an electrician in to check things out?