Hi - forgive me if this is very basic, but I have a transformer for 240 - 240 with a center tap which I intend to use to provide two 120VAC lives, summing to 240VAC, with the center-tap providing an earth reference. Diagram attached. On running this transformer, I get some strange readings and want to check that I have a) identified the leads correctly and b) that my understanding of what it does is right. There are four leads for the secondary (two red, two black), and I assume that two of these need to be wired together to make the center-tap. Is there an easy way to identify what two wires these should be? Using a VM, I see that the two black wires have a very tiny voltage developed across them, while the reds have 240V and the paired black/reds have 120V, so presume that the blacks are the center-tap. Is this likely to be right? Now, If I've got the above right, joining the two black wires (E1 in the diagram) should effectively be at zero voltage with reference to a real ground - but I am showing circa 80V, which indicates that there is some fault. Any clues as to what I might be doing or understanding wrong here? Thanks.