I have a step down transformer that will take 220VAC to 110VAC to use with electronics from the US. I do have 110VAC coming out of the secondary side. A surge protector is following but when I put an outlet tester it indicates 'open ground'. I measured from the hot to ground and got 78VAC and from the neutral to ground and got 30VAC. Is this normal and safe to plug in electronics into the power strip? Do I have to attach the neutral from the transformer secondary to the chassis ground?