Nest Power Connector to Taco SR503 exp

[MrDrewT]

Looking for help. 
maybe @Patrick_Caezza can help here. 
I have a nest learning thermometer that controls both AC & heat via zone 3, but no C wire to provide continuous power to the Nest unit (was running off of Rh wire for about 9 months). I bought a Nest Power Connector but I’m not sure about how to wire it to the Taco sr503-exp. The installation guide from Nest says that AC+Heat units should have an R, W and Y wire, but as you can see in the picture, I only have R and W. Should I try connecting it anyway, or will it fry the board?Please help.

 

 

[Patrick_Caezza]

@MrDrewT 

You have one of the newer Taco Switching Relay boards with a C terminal for each thermostat.

You should be able to install the Power Connector like this.

[MrDrewT]

Thanks @Patrick_Caezza two questions:

1.) My system is for both AC and Heat, will this set up still apply?

2.) Once I set up the adapter do I switch the wires in the nest thermostat housing, moving the wire in the Rh spot over to the C spot?

[zoeuvre]

Hi folks, 

@MrDrewT, thanks for posting here in the Community forum. The answers to your questions are the following: 

1. Yes, the Nest Power Connector will work for both of your AC and Heat.
2. No, you don't have to move any wire from the Nest Learning Thermostat base because their positioning is as it should be. Therefore, the Nest Power Connector will be the one to provide a sufficient power supply to the thermostat along the thermostat wires.

Let us know if you have any other questions. We're happy to help.

I appreciate your help, @Patrick_Caezza. 

Best,

Zoe

[zoeuvre]

Hi MrDrewT, 

I wanted to check and see if you are still in need of any help. Please let me know, as I would be happy to assist, and answer any questions you may have.

Thanks,

Zoe

[zoeuvre]

Hi there, 

Just one quick final check in here since activity has slowed down. We'll be locking the thread in the next 24 hours, but if you still need help, I would be happy to keep it open. If there's more we can do, just let me know. 
 

Regards,

Zoe