10-29-2023 10:52 PM
Hi there,
I just bought a Nest 3rd gen thermostat.
My heating cooling is a Jaga system. Honestly not sure where to put some of the wires from the existing Thermostat (https://iportal2.schneider-electric.com/Contents/docs/II-SE8300-A4.PDF)
In the existing thermostat, wires are connected to:
5
- color: red
- PDF description: RC / 24V Hot
- HVAC (end connection) description: 24VDC+
6
- color: black
- PDF description: 24 V Com
- HVAC (end connection) description: 24 VAC COMM Supply
7
- color: red (jumper from 5)
- PDF description: RH / Aux Heat
- HVAC (end connection) description: n/a?
8
- color: white
- PDF description: Aux heat
- HVAC (end connection) description: 2 way zone valve
11:
- color: teal
- PDF description: OU11 normally open cool valve
- HVAC (end connection) description: Jaga fan speed
12:
- color: brown
- PDF description: OU12 - normally open heat valve
- HVAC (end connection) description: 6 way valve command
24:
- color: blue
- PDF description: UI24 "not used"
- HVAC (end connection) description: 6 way valve control
Wire config on current thermostat
Current Thermostat Wiring Guide
10-29-2023 11:00 PM
I also want to mention that the system does have 4 fan settings:
- low
- medium
- high
- auto
Any ideas @CoolingWizard ? I see you are a wizard on these forums.
10-29-2023 11:17 PM
There are also 2 other rooms with independent fan/temp control. However, the primary thermostat in this post controls wether the entire system is using heating or cooling and I believe it communicates that back to the other thermostats in other rooms.
10-30-2023 07:57 PM
I don't have high hopes the Nest will work with this system, and I'm not terribly familiar with them myself. But if you want to try, from the documentation, it seems to me the red wire on #5 terminal is your RC terminal on the nest. Black on #6 is common and will go to Nest C terminal. Jumper between 5 and 7 is not needed in the nest as they have internal jumpers. White wire is auxillary heat and would go on Aux on Nest. Brown is heating and would go on W1 on nest. Green is cooling, Y on nest. Blue is just parked and not being used. Do not hook up to any nest terminals.
Again, wouldn't be surprised if it doesn't work, but do let me know if it does.
- Jersey Mike
10-30-2023 08:10 PM
Based on the information that you posted, your current system is not compatible with any of the Nest thermostats.
11-01-2023 03:10 PM
@JerseyMikeHVAC @Patrick_Caezza
I tried Mike's recommendation. Didn't work.
I do think the Green cable is for the fan (tested and it does control it).
For the above post, I would look at the HVAC label instead of the PDF description.
- blue: 6 way valve control
- brown: 6 way valve command
- white: 2 way zone valve
But if there is still an agreement Nest won't work, then I will return them.
Do you have any recommendation for smarter thermostats (remote controllable) that might work?
Here is a picture of the radiant heating/cooling system for reference (you can see a small knob which is the fan speed control): https://ibb.co/4j68HD7