Honeywell boiler relay

barmuley

I’m trying to identify where the common wire should be attached?  Honeywell RA832A 1066

HVACNUT

There's no available Common in that relay. Even if there was, the transformer is too weak for what you want. 
You need a dedicated transformer and isolation relay. 

barmuley

So there is no way to get power to a nest thermostat via ‘c’ wire using this relay?

are there any work a rounds? 

For example, since I have all the wiring running from the basement to the 2nd and 3rd floor thermostats, is it possible to connect to one of these (see pic) in the basement and just plug it in?  Or do I need to add a transformer and isolation relay?  

Note: I don’t want to plug this adapter in next to the termostats. 

Jamie Hall

Not using that relay, there isn't. However, if when you strung your wires you strung enough of them to each thermostat, the easiest way to do it is with a power transformer -- say 40 VA or bigger -- in the basement just to power the thermostats, and then use the other wires to bring the thermostat signal back down to wherever it needs to go. Often the only wires you will need are a red wire, which goes to the ungrounded transformer secondary lead (some transformers ground one side, others don't) and to the Rc or RH connection on each thermostat. Then another wire -- often green -- which goes back from the C (common) connection on the thermostat to the other lead of the transformer, and a white wire from the thermostat output to whatever is to be ccontrolled. Then a wire goes from whatever is being controlled also back to the red terminal of the transformer.

EdTheHeaterMan

This should work

I posted both Nest thermostat bases, since I don't know which thermostat you have. This is NOT a diagram that shows 2 thermostats connected to one RA823A relay, Just one thermostat with an optional sub-base. Choose only one thermostat

barmuley

Ed,

like this, or does it have to also be connected to “T”

Jamie Hall

You have to have both the white and red wire connected to T - T as @EdTheHeaterMan showed it.

EdTheHeaterMan

Also to T.

Thermostat R C is the transformer.
Thermostat R W is to call for heat

R is used on two different circuits at the same time

If your Nest has RC and RH... you must use RC That's why I added the optional sub-base

EBEBRATT-Ed

Here is an attached diagram of what I do and it works 100%. In your case the orange and yellow wires from the rib relay would connect to T & T on your relay.

EdTheHeaterMan

EBEBRATT-Ed said:

Here is an attached diagram of what I do and it works 100%. In your case the orange and yellow wires from the rib relay would connect to T & T on your relay.

This will work however there is an extra relay that is not necessary in this design. I would try this one first. I'm pretty sure it will work for you.

HVACNUT

barmuley said:

So there is no way to get power to a nest thermostat via ‘c’ wire using this relay?

are there any work a rounds? 

For example, since I have all the wiring running from the basement to the 2nd and 3rd floor thermostats, is it possible to connect to one of these (see pic) in the basement and just plug it in?  Or do I need to add a transformer and isolation relay?  

Note: I don’t want to plug this adapter in next to the termostats. 

I don't use those things in the professional field so I'm not familiar with it. It's certainly not something I'll have in the van when it doesn't work in 6 months. 

EdTheHeaterMan

HVACNUT said:

I don't use those things in the professional field so I'm not familiar with it. It's certainly not something I'll have in the van when it doesn't work in 6 months.  

Actually you do have something on your truck to do that. As long as it has a 20VA rating or higher.