Workshop Status:
In Progress
EPA Certification:
Not Texted
Employment Status: Not Provided
Nicholas J Bregenzer at HVAC Technical Academy – Central Florida
Nicholas J Bregenzer video – Low Voltage Wiring
Nicholas J Bregenzer video transcript – Low Voltage Wiring (Training Video Transcript)
00:00:00
Hi, my name is Nick with HVAC Technical Academy and today I will be talking about low voltage wiring, also known as thermostat wiring in HVAC. Think of low voltage wiring as the nervous system of our HVAC unit. It sends signals to different parts to power up the unit. So, we typically get our power from our transformer, which brings in 240 volts and steps it down to 24 volts. That’s what our thermostat wire runs on. Now, we have several different colors on our thermostat wire. It’s important to
00:00:44
not go by the color necessarily, but the terminal of the corresponding letter in our thermostat. So, it plugs into here. And a typical wire setup of what we see on a heat pump, we have R, our red wire is our 24 volts that powers the system. We have blue and black are common. Orange powers our reversing valve in a heat pump system. Green powers the indoor blower motor and the air handler. Yellow energizes the Y terminal in the outdoor unit and white is our call for our heat strip.
00:01:31
Now we can have wires going into the thermostat. This is essentially if this wire is our nervous system, our thermostat is the brain of the system. It plugs in from the wall into each of these terminals and you can adjust the thermostat in order to call for certain things. So, for example, if you wanted to call for cool, our R wire, our 24 volts would energize our G wire to power the fan blower motor and our Y wire to power the outdoor contactor. We don’t have many problems associated with low voltage, but there are a few.
00:02:19
There could be misplaced wires. So, if we have a Y wire and a call for heat mixed up, we could be calling for cool on the thermostat and be getting heat. Things you want to check for are breaks in the wire, misaligned wires, and we also have several safety switches in the system. We have a low pressure and high pressure safety switch that, if we’re not getting enough refrigerant or we have too much pressure in a system, it could disrupt the 24 volt circuit and
00:02:54
turn our system off. We also have some fuses that could be blown that interrupt the circuit and turn the system off. And that is our class on low voltage wiring.