Nest with commercial 10 ton rooftop unit

[jcalagaz]

I have a Goodman 10 ton package unit that I am trying to install a Nest Learning Thermostat on.

When I first installed it the previous thermostat only had a Y1 and when hooked up that way I got a fault when I "tested" the wiring.  I have gone to the unit and found that the unit has Y1 and Y2 jumpered together.  I have removed the jumper and connected an unused wire (brown) to Y2 at both the unit and the Nest.

I am not getting the error any longer but I am not sure that the second compressor is coming on.  I am in a commercial building and really don't "need" two stage cooling (it barely keeps up in the heat of the summer) but it seems the nest doesn't like that setup.

1. how can I tell if the second stage is on?

2. how do I know if my Goodman is a two stage unit or is just a two compressor unit? (CPH-120)

3. how can I test the voltage at the nest to see if it is "right"

thanks for any help and advise!

[Jake]

Hey jcalagaz,

Apologies for the delayed reply. I wanted to follow up and see if you still needed any help? Please let me know, as I would be happy to take a closer look.

Best regards,

Jake

[Jake]

Hey jcalagaz,

I just wanted to follow up and ensure you are good to go. Please let me know if you have any questions from here, as I would be happy to take a closer look and assist you further. 

Best regards,
Jake

[jcalagaz]

not really, I had to take the nest out and put the old thermostat back in.  Best I could tell the 2nd compressor (not stage) was not running (and I am NOT a HVAC guy)  

When I only one Y1 was hooked up and the Y1 and Y2 were jumpered at the unit, it kept throwing the error.  

I gave up...:)

[Jake]

Hey jcalagaz,

Sorry to hear it didn't work out for you. If you ever decide to try again and run into the error, please feel free to reach back out at any time. You could also have a Nest Pro come out and take a closer look. They would be able to set up the device and ensure everything is working properly. 

Best regards,

Jake

[Jake]

Hey jcalagaz,

It has been a few days since the last reply, and I am going to lock the thread at this time. If you have any questions, please feel free to create a new post. 

Best regards,
Jake