wifi honeywell thermostat control unit

[paulga]

Thats a conundrum.
It's 24v powered relay logic. The relays have a diagram on top. I'm assuming powered closed.
So if closed they are getting 24v.
Verify your meter settings and retest.

I think you are referring to the relay box on the top right corner. It looks similar to this ac contactor but does not have diagram printed on top.

If the air conditioner is working, should there be 24v b/t the red and green terminals outside of the control box?

 

[Turtle Blues]

Green outside the control box is fan. Red is 24vac. Jumping them together should energize fan. You will not get a voltage reading between them as you are at 2 points on the same side of the control loop. The other side is at the relay in the cabinet.

 

[Turtle Blues]

If a relay is pulled in you might get a voltage reading because it is seeing through the relay.

 

[Bmarler]

Use the ac setting on your meter Jay, not dc. It’s 24 volts ac coming off the transformer.

 

[paulga]

Green outside the control box is fan. Red is 24vac. Jumping them together should energize fan. You will not get a voltage reading between them as you are at 2 points on the same side of the control loop. The other side is at the relay in the cabinet.

Per suggestion from @Bmarler I tested the voltage again and got 26.5vac b/t the green common wire and the R terminal. I was prejudiced by the safe and low voltage level thinking it was dc.

The green wire is attached together with a yellow wire to the relay box using a 3 way quick disconnector. Is it common practice to add a second 3 way quick disconnector in order to add the C wire?

 

[Bmarler]

In that particular box I’d say anything goes. It won’t hurt to add another splitter.
Personally, I’d be embarrassed to say I built that. Oh well, it probably looks fine with the lid on.

 

[Turtle Blues]

Ouch, that was just hurtful.
I'm the dinosaur that remembers when it was state of the art.
That box was assembled by a human, standing at a workbench, in Florida, in a building without AC. Long before pressed circuit boards took over the industry.
OP will be able to add a wifi stat for about $100.
A micro air wifi stat and compatible board to retrofit current products will run about 8 boat bucks.
So much for digital circuitry making products less expensive.

 

[Bmarler]

My wife and I build industrial control equipment. So we are certainly up to speed on best practice when it comes to wiring a panel.
I didn’t mean to offend with that comment, and am very apologetic if offense was taken.

 

[paulga]

In that particular box I’d say anything goes. It won’t hurt to add another splitter.
Personally, I’d be embarrassed to say I built that. Oh well, it probably looks fine with the lid on.

Thanks. now i'm clear what to do.
we are looking at a control box that was made at least a decade ago. i'm sure nowadays their internal design has become more simplified and organized

 

[Turtle Blues]

No, no offense taken. My attempt at humor did not come off as intended.
Hopefully we have sorted through the wiring to the point that OP can get his wifi stat operational at a fraction of the cost. Hoping that this R22 unit still has some life left in it.

 

[Bmarler]

I’m still running an r22 unit too. It came uninstalled with the boat when we purchased it.
I did a temp install thinking I’d replace it in a year or so, but it just won’t die…

 

[paulga]

Hmm, I can't say yes to your question, looking at your photo neither wire goes to the stat base uninterrupted, but that doesn't matter. Verify with a meter that the red wire is what eventually lands on the R terminal on the base.
Green landed on the stat base according to standard color coding would be the fan.
The module you have above is intended to save you from having to pull an additional wire.
It splits what is wired through it to derive a constant common which it identifies as K.

I want to confirm the wiring after adding the c wire thermostat

1. from the control box, the terminals R,G,W,B will be wired to the c wire adapter's EQUIPMENT Rc,G,W-O/B,Y ?

2. from the c wire adapter's THERMOSTAT section to the thermostat base: Rc goes to RC (jumped to RH), W-O/B to W. Then how to wire the other two terminals K and C?

 

[Turtle Blues]

That should be answered on about page 14 of the installation instructions for the thp. Sorry limited to marginal phone service - not trying to dodge the question but I cant quite make out what the page shows.
Instructions appear straight forward for landing your equipment connections so thought would be to just add wires as necessary from the module to your new stat base per the Honeywell diagram.

 

[paulga]

That should be answered on about page 14 of the installation instructions for the thp. Sorry limited to marginal phone service - not trying to dodge the question but I cant quite make out what the page shows.
Instructions appear straight forward for landing your equipment connections so thought would be to just add wires as necessary from the module to your new stat base per the Honeywell diagram.

Thanks.
I found a two page manual on the resideo website.

"G and Y wires are converted to C and K"

 

[Turtle Blues]

I would caution to make sure you are correct with the specific product you end up using. The diagram above does not look the same as the Honeywell products you referenced. The devil is always in the details.

 

[paulga]

Thats a conundrum.
It's 24v powered relay logic. The relays have a diagram on top. I'm assuming powered closed.
So if closed they are getting 24v.
Verify your meter settings and retest.

It's sort of a pleasing surprise that the ac started running when I closed the breaker, after adding the c wire and c wire adapter and installed the new thermostat. Because the old thermostat became unable to control the ac after I added the c wire& adapter. I thought it could be some of the terminals were not crimped well. But after I installed the new wifi thermostat, the new thermostat works.

the voltage as I measured is 28vac between the common wire and the red terminal, while I expected 24v. This is the reverse cycle in the salon while the earlier measurements and photos were taken of the reverse cycle unit in the aft cabin for easier access. Does 4v difference raise any concerns?

 

[Turtle Blues]

No, not in this instance. Transformer is a little high on output but the system should handle it.
Glad you got it working, hopefully squeeze a few more years out of it.

 

[paulga]

No, not in this instance. Transformer is a little high on output but the system should handle it.
Glad you got it working, hopefully squeeze a few more years out of it.

The contactor on the upper right corner is called a relay. So it's an automatic conditional switch. What's the condition that this relay is closed?

 

[Turtle Blues]

Need to look at wiring diagram, is it on the inside cover? Or logic diagram in owners manual.
Generally 2 relays 1 for the fan and 1 for the reversing valve.

 

[paulga]

The manual in post 6 has logic wiring diagrams. This one is for the unit.

Are both the fan and reverse valve relay controlled by the temp setting on the thermostat unit?

Here is the diagram for the electrical box

 

[Turtle Blues]

The relays should be commanded (energized) by the stat soft buttons below their status display. Fan on should be continuous, auto setting energized by stat.
For the reversing valve you need to see with a voltage meter which setting, heating or cooling is driving the reversing valve. The magnet is energized to drive it to one of the cycles and it returns to the opposite when deenergized. I hesitate to guess which is which.

 

[paulga]

The relays should be commanded (energized) by the stat soft buttons below their status display. Fan on should be continuous, auto setting energized by stat.
For the reversing valve you need to see with a voltage meter which setting, heating or cooling is driving the reversing valve. The magnet is energized to drive it to one of the cycles and it returns to the opposite when deenergized. I hesitate to guess which is which.

Thanks.
The (freon) RV solenoid is "on unit", meaning it's on the compressor? It's a far reach, I didn't see which fitting it is.
When the fan relay receives a "fan on" signal from the stat, how does the fan relay switch the fan on?

 

[Turtle Blues]

Just the reversing valve itself is mounted next to the compressor. 2 pipes in the bottom 3 out the top, coil magnet on the end.
The fan on (or auto in combination with stat) setting allows 24v through the stat wires energizing the coil magnet inside the relay closing the other side to allow the 120v through to complete the fan circuit.

 

[paulga]

Just the reversing valve itself is mounted next to the compressor. 2 pipes in the bottom 3 out the top, coil magnet on the end.
The fan on (or auto in combination with stat) setting allows 24v through the stat wires energizing the coil magnet inside the relay closing the other side to allow the 120v through to complete the fan circuit.

I didn't see the reversing valve. This is the whole unit (in the aft cabin):

Behind the fan, the cylinder container (model 2r8s3r126a) is the compressor. Is it supposed to have two pipes in the bottom and 3 out the top?

 

[paulga]

The relays should be commanded (energized) by the stat soft buttons below their status display. Fan on should be continuous, auto setting energized by stat.
For the reversing valve you need to see with a voltage meter which setting, heating or cooling is driving the reversing valve. The magnet is energized to drive it to one of the cycles and it returns to the opposite when deenergized. I hesitate to guess which is which.

I didn't know the new thermostat runs by either a default or customized program, and it is important to select the fan type correctly for the reverse cycle ac (function #3 set to 1, see attached). When I finished the installation, I left it in heating mode. Now the thermostat works in either heating and cooling mode, but the ac only blows out cold air. I tried to recall what went wrong. In the next morning after the installation, the ac kicked on in heating mode but the fan didn't run. So the ac operated like that for a couple of hours. I assumed the ac would have tripped if there was overheating, so I didn't give it much thought. It nevertheless could still be the reason that some component was damaged at that time. @Turtle Blues how to trace the issue and test?

 

[paulga]

Braden from FMS provided me a trouble shooting guide. I followed through to find that water was not running when the ac unit was "running". Per his suggestion, I reset the high pressure switch, then problem solved. The water is running now when the compressor runs, warm air is blown.