I have a 450VA isolation transformer. The transformer is supplied from a three prong outlet. I've taken some measurements with my DVM they show a voltage between lines to ground on both outputs. The combined voltages between both lines to ground don't even add up to the line to line voltage.
Heres a schematic of the measurements.
I just got this transformer but I've already used it to test a few line powered circuits. These measurements must be wrong or I would have blown fuses when hooking up my scope to the circuits.
I use the isolation transformer on the test circuits not on my scope. For example if I were to hook up a flyback to the isolation transformer and use my scope (un-isolated) to take primary side measurements according to those measurements I should be getting a short through my scope ground lead. This hasn't happened both the isolation transformer and the flyback are fused; neither blew. Can anyone explain this?