This accepts either 115 or 230V input.
Its output is 0-270V when the right voltage is applied to the right input.
If you want 0-135V output, feed the 120VAC into the 230V input.
The current rating will apply. 9A I believe.
If the unit's good, this should solve the issue.
Thanks Patrick,
That's what I thought it was, a dual input voltage type. Your terminal board and label is a lot more clearly marked. The one that the OP pictured is not that clear.
I think that if you connect it to 115v it will give output voltage all the way to 270v. The 115v terminal must be half way between the common and the 230v terminal. The output wiper will run to the far end of the winding yielding the 270v output. Does not look like there is a terminal connected at the high end of the winding, so the unit can only be used in the step-up mode.
The way to use it on 115v and yielding only 135v is to connect 115v to the 230v terminal.
So, connect the 115v line to the common and the 230v terminal and the output will be only around 0v-135v. Of course the normal line voltage is more like 125v so the output would probably be 0v-148v.
Fred