cancel
Showing results for 
Search instead for 
Did you mean: 

Wiring connection

srser89
Community Member

Hello,

I woudl need some guidance on the connection of the wires. The picture below is the current thermostat I have installed. Since it does not have letters I do not know where should I connect each of the colors. Could anyone help me?

It has heat pump, AC and fan.

WhatsApp Image 2022-11-24 at 18.14.16.jpeg

Thanks!

1 Recommended Answer

CoolingWizard
Silver Product Expert
Silver Product Expert

Here is the information you are seeking. Your thermostat is using a digital communications protocol that is manufacturer proprietary. The wires you see use RS-485 to communicate with the indoor unit’s control board. The Yellow wire is Receive Data, the Blue wire is Transmit Data, the Red wire is 12VDC to power the thermostat and the Black wire is the ground.

Conventional HVAC systems are more basic and utilize 24VAC power to control everything. The thermostat takes the 24VAC and when commanded, will call for Heating by sending the 24VAC received on R, to W and that wire attached to the W will go to the heating system and start the heating cycle. Likewise, if the thermostat is commanded to initiate cooling, it takes the incoming 24VAC on the R, and connects it to the Y. that wire attached to Y will signal the indoor blower to start and the outdoor unit (compressor, and fan motor). If you switch your FAN switch from Auto to ON, the thermostat connect the incoming power on R and connects to the G. The wire attached to G, will be connected to indoor unit and will signal the indoor unit to turn on the Blower.

In order to switch to a conventional control system, you will need to install a new thermostat cable, attach the conductors of the new cable to the thermostat at one end, and the other end of the cable to the indoor unit control board , where it will be cross connected to a cable that goes to the outdoor unit. Most manufacturers that use proprietary digital controls, also ensure the indoor unit control board also supports the conventional type systems.

Ken, The AC Cooling Wizard

NestPro and HVAC company owner

View Recommended Answer in original post

5 REPLIES 5

CoolingWizard
Silver Product Expert
Silver Product Expert

Here is the information you are seeking. Your thermostat is using a digital communications protocol that is manufacturer proprietary. The wires you see use RS-485 to communicate with the indoor unit’s control board. The Yellow wire is Receive Data, the Blue wire is Transmit Data, the Red wire is 12VDC to power the thermostat and the Black wire is the ground.

Conventional HVAC systems are more basic and utilize 24VAC power to control everything. The thermostat takes the 24VAC and when commanded, will call for Heating by sending the 24VAC received on R, to W and that wire attached to the W will go to the heating system and start the heating cycle. Likewise, if the thermostat is commanded to initiate cooling, it takes the incoming 24VAC on the R, and connects it to the Y. that wire attached to Y will signal the indoor blower to start and the outdoor unit (compressor, and fan motor). If you switch your FAN switch from Auto to ON, the thermostat connect the incoming power on R and connects to the G. The wire attached to G, will be connected to indoor unit and will signal the indoor unit to turn on the Blower.

In order to switch to a conventional control system, you will need to install a new thermostat cable, attach the conductors of the new cable to the thermostat at one end, and the other end of the cable to the indoor unit control board , where it will be cross connected to a cable that goes to the outdoor unit. Most manufacturers that use proprietary digital controls, also ensure the indoor unit control board also supports the conventional type systems.

Ken, The AC Cooling Wizard

NestPro and HVAC company owner

aatienza
Community Specialist
Community Specialist

Hey folks,

srser89, checking in — we hope you've got the answer you're looking for. Let us know if you have more questions in mind.

I appreciate the help, Ken.

Thanks,

Archie

aatienza
Community Specialist
Community Specialist

Hey there,

I just wanted to follow up to see if you still need our help. Please let us know as we would be happy to answer any questions you may have.

Thanks,

Archie

srser89
Community Member

hey!

all is clear, I will have to contact a specialist in order to do the setup since extra wiring connections are needed.

Thanks anyway!

Markjosephp
Community Specialist
Community Specialist

Hello folks,

Thanks for assisting, Archie.

Sounds like a plan! Thanks for updating us, @srser89. So we'll lock this thread in 24 hours. If you need more help, don't hesitate to give us a shout by creating a new post so we can assist you right away.

Best,

Mark