So I learned something new today… contactors are marked A1 and A2 – I thought that was very nice… what I didn’t know is that A1 is the positive and A2 is the negative, and should be connected thus so the magnetic blowouts work… mmm… looking at my old contactors one was correct and the other was incorrect (happily – for once) the broken one is the one that was reversed… never happens 🙂