SERVICE CLINIC

Through many years in the HVAC industry working as a technician and service manager, I found the area which gave me the most trouble is low voltage electrical. One method I use to resolve this problem is what I call "halving."

"Halving" is working with a wiring diagram by starting at its mid point, and then continually "halving" the diagram to pinpoint the problem. This process works best with a ladder diagram which gives us the sequence of operation, but will also work with a pictorial diagram if you understand how the controls work. I will explain this on a pictorial diagram, which normally is not used for troubleshooting.

The purpose of "halving" is to save time during the troubleshooting process. There is no reason to test all the switches, relays, thermostats, etc. from start to finish if the problem doesn't exist in that part of the circuit. The idea is to break the circuit down and find the problem without going through the entire circuit. This is done with your eyes, ears, an electrical meter, and a process of elimination.