Measure secondary voltage with a digital multimeter

[valleyvic]

Hello
I have a power transformer that works out of 120V and I would like to find out the secondary voltage that this transformer brings out.
As you can see on the attached pictures, the left side shows four wires and the right side shows one pair, which is 120VAC. What (pairs of) wires from the left side carry the secondary voltage?
Thanks

 

[Conrad Hoffman]

The secondary is all one winding. They use black for ground, so I'd measure the other three against black.

 

[rayma]

Be very careful to not short anything to anything else.

 

[valleyvic]

So, there should be 3 possible pairs, right?
1 : Black-Red
2 : Black-Blue1
3 : Black-Blue2

 

[rayma]

Yes. Because black is ground, the measured AC voltages as listed will reflect the actual voltages used by the circuit.

 

[valleyvic]

Great. Thank you Conrad and Rayma.