If your AC isn't working, or if it's making weird sounds, the problem could be with the transformer. A transformer can be fried by anything that causes a power surge, such as lightning. If you know where the transformer is inside your AC, you might notice burn marks or melted areas that confirm the part has been damaged. Here's why your air conditioner transformer is so important, how to tell if it's bad, and a look at how it's replaced.
The Transformer Increases Or Decreases Power
Increasing and decreasing power may not seem like an important job, but the function of your air conditioner depends on it. The power supply to your AC is too high to go directly to the electronic controls. Instead, the power passes through the transformer that steps it down so lower voltage comes out the other end and goes to the control board. The reverse can also happen when a part in the AC needs the power to be stepped up. Without a transformer, your AC couldn't function because high voltage would fry the electronic parts, and HVAC equipment is controlled by signals from an electronic control panel.
Multimeter Tests Confirm The Transformer Is Bad
It's difficult to know if a transformer is bad without testing it. Even if you see the transformer is melted, it may have been fried by another faulty part, such as the contactor. The transformer may hum when it's going bad, but a similar noise is made by a bad capacitor, so an odd sound isn't a definite sign.
When the transformer is bad, your AC probably won't start and run. That's a good indication the transformer is bad, but other things cause this problem too. An air conditioning repair technician can test the transformer with a multimeter and know for sure if the part is bad.
A Bad Transformer Is Easy To Replace
If the only thing wrong with your air conditioner is a bad transformer, then replacing the part should get your AC working again. The transformer is fairly easy to access once the cover panel is off. It's held in the air handler with a bracket, and it has wires that attach to the control panel. Once all the wires are disconnected, the old transformer can be pulled out and a new one put in.
The tricky part is determining if there is another faulty part that fried the transformer. If there is a bad part somewhere, the new transformer may get burned out too. The air conditioning repair technician checks out other parts and if one is found to be faulty, it will be replaced too so the transformer can do its job properly.