Q: I have several Altronix T24130 transformers. 24 VAC, 100VA. There are three terminals on the secondary side. What is the center (unused) terminal for?
A: I spoke to the manufacturer who said that the transformer you have might be capable of two different voltages so please put your voltmeter on terminals one and two and then one and three and then two and three and record your data and then you will know what terminals you need to use for your application.