BMPlus 3000 with 4 Zones, 2 Stage A/C and Nest Thermostats

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Joined: Sun Mar 07, 2021 8:25 pm

BMPlus 3000 with 4 Zones, 2 Stage A/C and Nest Thermostats

Post by U019806 »


I have a new House with 4 Zones and the Nest 3. Gen Learning Thermostats hooked up to each Zone in SW Florida.
The Air Handler Unit is a Ruud RH2V6024STANJA with a RA1760AJ2NB Model Series Condenser Unit.

After living in this new House for about 2 month now it seems to me that the A/C is only running on one Stage, always the same strong draft in the rooms when cooling or heating. So I looked at the Equipment setup in the Nest Thermostat and noticed that only Y1, W1, G, C and Rc are connected, even though there are terminals for Y2 and W2.

I called my HVAC installer and he, at first, told me that it is fine that way and that the Zone Controller would take care of the 2 Stages. However he also told me that he would look into it, since that was only the 2nd System like this that he installed and there might be some jumpers that needed to be set differently.

So I looked at my manuals and after searching the net, fortunately found your site.

I located the BMPlus 3000 with the extra BMPlus 5000 board for the 4th Zone in the garage and took a closer look at it.

Now this board only has 6 lines for each Thermostat and this is where the 5 wires from the Nest Thermostats are connected. The Connectors on the System side however, does have Y2 and W2. There are 2 blue wires connected to Y2 and 2 yellow wires connected to Y1. For the heating there is only a white wire connected to W1, W2 has no wire connected. SAS and OAS are also not connected.

When I run the A/C in different rooms, only the Y1 LED comes on. I tried several different Temperature settings in one Zone or more Zones but the Y2 LED never came on.

Now here are my questions:

1. Is the BMPlus 3000 really the best option for this 2 Stage A/C System or would the UZC4 Model not be the better choice, since it has Y2 and W2 wiring for the thermostat and all 4 Zones on one board?
2. All my DIP switches are currently set to the factory default, is that correct for my A/C setup?
3. Would the 50%RULE - ON be advisable for my location and system?
4. The Potentiometers are set as follows: Staging Timer on 11, Low Temp Limit on 34, High Temp Limit on 172 and 2nd Stage Heat Differential on 5. Would you use these settings in Florida?
4. Should W2 not also be connected, or is that not really necessary in Florida?
5. The only Wiring Diagram I was able to find, that shows 2 Stage setup and wiring is the one on the last page of the manual. Would that also apply to me even though I have no 2 Stage Gas Heat?
6. In Florida it gets quite humid and the Nest Thermostat as well as the Ruud A/C are capable of doing dehumidification. In order to utilize this would the Zone Controller be bypassed, and how would dehumidification work with the 4 Zones? It would be fine with me if all 4 Zones would run dehumidification when selected on any one of the thermostats.

Ok, that was quite a bit now.

I would really appreciate any advice you could give me with my system setup.

Thanks, Alex.
Steven W.
Posts: 58
Joined: Tue Jun 25, 2019 9:13 am

Re: BMPlus 3000 with 4 Zones, 2 Stage A/C and Nest Thermostats

Post by Steven W. »

Hello my name is Steve I am one of the techs here at EWC .

Please give me a call today about your problem.

Thank you

Steven R. Weisneck
HVAC Zoning Technician
Tel: (732) 446-3110 Ext. #461
M-F 8:00am - 4:30pm
Steven R. Weisneck
Technical Engineer
Tel: (732) 446-3110 Ext. #461
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