Hot or cold side of transformer

[philws]

 I have a hobby transformer from bachmann  how  do I tell which Wires  are hot on it I have a plain black wire and I black with a white stripe wire?

[jbrock27]

Have a digital multi meter?

[Hunt]

Which variable DC terminal is positive and which is negative is determined by the position of the transformer direction switch.

[philws]

Yes I have a digital meter.  I'm not using the control part of the transformer just electric part I'm using it for my switches that I had just bought .

[Len]

If you're talking about the low voltage AC side of the transformer it doesn't really matter. Just pick one side as the "hot" and the other as the "return", then stay consistent with the return side being the common when wiring.

Len

[jward]

with ac there is no "hot" side. since household ac changes polarity 60 times per second, both terminals on ac will shock you the same.