(Wiring Problem) Switching from MARS2 Control Transformer (CT) to PROTECH CT
First, I would like to thank you for reading my post. Second, my MARS2 control transformer finally gave out, which, of course, stopped my entire HVAC system from working. However, when I went to the hardware store to purchase another control transformer the only kind they had was a PROTECH model.
The PROTECH model has a different wiring scheme from my previous transformer and therein lies the problem which lead me to you.
Originally, my Mars transformer was connected to color for color (Blk to Blk), (Blue to Blue), (White to White) and (Yellow to Yellow). Also, the red and orange wires weren't connected to anything but where taped off at the end.
However, my new transformer has almost the same coloring scheme BUT it has two yellow wires and I have no idea what to do with them.
look at the label on the new transformer. It will probably show you that the yellow wires are the low voltage wires. connect one to where the old blue wire was located and one to the old yellow wire location. that takes care of your low voltage side. Next, go to your high voltage side of your new transformer and find out which color wire is your common and hook it to the location that your old white wire was located. The next step is the tricky one. without knowing what type of unit or what voltage is coming into your air handler I cant tell you which wire to hood up. If the black wire was hooked up previously, I assume it is a gas furnace. In that case you will want to look at your new transformer and find the color wire that is 120 volt and hook that one to your old black wire location. Make sure you put wire nuts on the remaining wires. Good luck