HAI RC2000

[charliebarns]

I have a question about the humidity wiring for the RC2000. My HVAC guy says the Humidity portion of his install won't work with the RC2000 as he installs a separate 24V transformer which essentially has a 2nd common for the Humidifiers so that anytime there is a call for fan the humidifiers will kick in. He claims there is no way to hook up the humidifier component of the RC2000. Does this sound correct - or am I missing info here to understand the situation?

Thx

 

[RArbour]

Charlie,
From your brief description it sounds like the installer can connect the Dehumidifier common to the HVAC common (connect to the Cool transformer if separate heat/cool). This would allow the dehumidifier to use either the Fan or Dehumidifier control signal from the thermostat. These control signals apply 24VAC referenced to the common. The dehumidifier will still use the separate transformer for its normal operation.

Thanks,
Ryan

 

[charliebarns]

Hey Ryan thanks for the response. Does this also apply to the humidifier? There isn't a dehumidifer in this home but there are two desert springs humidifiers, one per furnace...

thanks

 

[RArbour]

Charlie,
Your a little quick on those responses....the tab + enter messed me up at first.
The same applies to the humidifier.

Ryan

 

[charliebarns]

Charlie,
Your a little quick on those responses....the tab + enter messed me up at first.
The same applies to the humidifier.

Ryan

Thanks again Ryan. I'll pass this along to him and see if it calms him down.

Kind Regards,

CB

 

[dutchyn]

I have my RC2000 controlling a Honeywell 225 bypass humidifier on a ClimateMaster Tranquility 27. There is a gotcha: the current output from the RC2000 isn't enough to open the solenoid valve. So I followed the usual HVAC process of installing a bog-standard 24VAC MY5N relay, controlled by the humidifier line. The relay switches another 24VAC current to the solenoid. I also took advantage of the DPDT relay to make sure that the G (call for fan) line is also enabled whenever humidity is called for. The wiring diagram is attached.

View attachment humidifier.pdf

Chris D.

 

[charliebarns]

I have my RC2000 controlling a Honeywell 225 bypass humidifier on a ClimateMaster Tranquility 27. There is a gotcha: the current output from the RC2000 isn't enough to open the solenoid valve. So I followed the usual HVAC process of installing a bog-standard 24VAC MY5N relay, controlled by the humidifier line. The relay switches another 24VAC current to the solenoid. I also took advantage of the DPDT relay to make sure that the G (call for fan) line is also enabled whenever humidity is called for. The wiring diagram is attached.

View attachment 2525

Chris D.

thanks Chris I'll pass that along to the HVAC guy. I wish I understood my HVAC guys wiring better to be able to explain this particular setup. He did try a number of thing yesterday and has everything but the call for humidity working. The only thing I understood him saying was that he wires the humidifiers with their own 24VAC and as such they have their own common. It has something to do with a call for fan (in heat or cool) during a call for humidity. I'll need to get him to explain it better.

CB

 

[dutchyn]

The only thing I understood him saying was that he wires the humidifiers with their own 24VAC and as such they have their own common. It has something to do with a call for fan (in heat or cool) during a call for humidity. I'll need to get him to explain it better.

In my setup, the humidifier is isolated from the thermostat via the relay -- that should satisfy your installer. I suspect he may have thought that you wanted the H wire trigger the humidifier and the fan directly: i.e. also connect the H to the G input on the furnace. That would give the behaviour of fan on means humidifier on also. Furthermore, if the humdifier needed/used it's own 24VAC source and you tied the H and G together, then you have two competing sources and commons on one pair of wires -- this seems dangerous and may burn things out.

On the other hand, the relay and mount + box cost about me about $40 (I used some scrap wire I had laying around); so it's not trivially inexpensive.

Here in Saskatchewan, we don't need dehumidifiers, so I haven't worried about how to drive that ... I'd probably do the same relay thing, if needed.

Chris D.

 

[scottlee]

Thanks for posting this solution to the problem I am facing too.

Chris, in your wiring diagram, you show the MY5N relay connected from H to C on the Omnistat. Do you have a Common wire from the Omnistat to the Tranquility? I have a 4-wire conventional without a common and I'm wondering if this setup will work?

Scott

 

[dutchyn]

Chris, in your wiring diagram, you show the MY5N relay connected from H to C on the Omnistat. Do you have a Common wire from the Omnistat to the Tranquility?

I do have a common to all the Omnistats. I don't know if it's needed; I suspect not -- because the humidifier line only provides limited current (hence the extra relay), so there's probably enough for relay operation without the common. I know that some people encounter insufficient power problems without the common, but I suspect it may be related to the number of thermostats more than anything else -- those backlights take a bit of current.

I have a 4-wire conventional without a common and I'm wondering if this setup will work?

Electrically, the setup with 4 wires is correct. Whether you end up needing additional power -- HAI offers a thermostat power isolution module (29A00-1) -- I cannot say without knowing lots more about the length and guage of wire you use, how many thermostats and their models, ... I would begin by trying it (nothing will break), and watching for situations where the thermostat(s) seem to reset themselves, especially on highest backlight. That symptom has been noted as a power problem, fixed by the isolation module, in other threads here.

Good luck

 

[charliebarns]

Back on my RC2000. I haven't worked out the relay issue yet, mainly b/c the HVAC guy is on vacation. I decided to hook them up to my Omni Pro II (2 RC2000 thermostats) and I'm running into a problem. I have one CAT6 from each thermostat homerun, and then connected in a Y and a single connection going to the Omni Pro II board. Main floor thermostat is set to ID 1, Serial 100, 1200. Upstars thermostat is set to ID 2, Serial 100, 1200. The main floor thermostat works fine in the Omni Pro II. I can see it no problem in PC access and Snaplink, and manipulate it fine. the upstairs thermostat is giving me grief, however. I can see it in PC Access and Snaplink and it mostly shows the correct temperature settings, that is until you try to manipulate it. Here is what happens:

Here are the temperature settings and the current temp:

Current temp: 23.5 C
Cool setpoint: 24.0 C
Heat setpoint: 19.5 C
FAN AUTO, HOLD OFF

send it MODE cool from PC Access or Snaplink - thermostat goes to off
sent it MODE heat from PC Access or Snaplink- thermostat goes to heat (furnace doesn't fire since temp is already above heat setpoint)
send it MODE auto from PC Access or Snaplink- thermostat goes to heat (furnace doesn't fire since temp is already above heat setpoint)

send it a different heat setpoint, say 16.5, display shows ~unknown~, FAN AUTO, HOLD OFF

I've checked and re-checked, re-terminated the wiring and I'm confident the wiring is OK. I assume connecting the two cat6 into the one cat6 and terminating on zone 16, output 8 is basically the same as daisy chaining the wiring.

Anyone have any other ideas?

Thanks

CB

 

[dutchyn]

Everything sounds fine, especially the daisy-chain idea: the install manual explicitly says it's acceptable. I do wonder though, for RS-232 connections, you need to remove the jumper from the fourth data terminal in the thermostat. But for HAI controllers (OmniPro...) you must use three wires and keep the jumper in place. Did you check that?

 

[charliebarns]

Everything sounds fine, especially the daisy-chain idea: the install manual explicitly says it's acceptable. I do wonder though, for RS-232 connections, you need to remove the jumper from the fourth data terminal in the thermostat. But for HAI controllers (OmniPro...) you must use three wires and keep the jumper in place. Did you check that?

Hi Chris,

I hadn't checked that but I just did and on both thermostats the jumper is in place... Strange behavior. Maybe an HAI guru will chime in...

 

[Ernie]

CB,

1. What do you have connected to Zone 2 on the Omni Pro II?
2. What is the zone "type" set for zones 2 and 16?
3. If you temporarily swap tstat 1 with tstat 2, does the problem follow the move or remain in the location?
4. What is the firmware verison in each of the tstats?

 

[charliebarns]

CB,

1. What do you have connected to Zone 2 on the Omni Pro II?
2. What is the zone "type" set for zones 2 and 16?
3. If you temporarily swap tstat 1 with tstat 2, does the problem follow the move or remain in the location?
4. What is the firmware version in each of the tstats?

1. Zone 2 of the Omni Pro II has an exterior door sensor attached which is currently 'Not Ready' since my permenant doors are not in place.
2. Zone 2 is set to Exit/Entry and Zone 16 is set to Auxiliary.
3. I unhooked Tstat1 (the current functioning thermostat) and just hooked up Tstat2 (the problem thermostat) and it seems to be exhibiting the same non-functioning behavior. I have not moved the locations yet but will do so and report back.
4. The functioning thermostat Firmware is 1.03 and the problem thermostat is 1.02C. The Omni Pro II is Firmware 3.1a.


Is there a firmware incompatibility?



Cb