Signaturestat and Harmony II

Here's an obscure one...

Dear Carol,

I'm wondering if it's possible to use a Signaturestat on a Harmony II controller for more than just cooling. At present, we only have three wires hooked up to each thermostat (honeywells) (C,R, and Y). What I'd really like to do is to have the ability to also run the fan from time to time so that the rooms get aired out.

I have been able to find a number of references online about the harmony II board being used in conjunction with a Signaturestat, but no clear answer yet how to tell the Harmony II board to engage the fan blower w/o engaging the cooling, as the Harmony II board has no G input. Is it possible or would I have to have the thermostats and the harmony controller updated?

Thanks Bill and Carol!

Unfortunately, we're only inching closer to an answer, not quite there yet.

It is true that the controller for the Harmony II board allows a user to set fans to circulate air continuously... and that feature would be halfway decent at solving my problem, if my installer had not decided to install these controllers right next to the board and the air handler in remote corners of the house. For example, climbing into the attic everytime to turn the fans on for circulation does get a bit old.

My understanding from reading the little I could find on the Signaturestat and the Harmony II board is that the SignatureStat can tell the board to engage the fans on a thermostat level by using some combination of the few thermostat terminals that are available on the Harmony II board (C,Y,R,O, and W) that the Harmony II board then interprets as a "G" call.

Perhaps the easiest thing is to buy a signaturestat, hook up all the terminals that are available on the harmony II board, and then see what happens... yes, I'll turn it all off before I make any connections.... and as you can see below, I have a backup plan.

One other way that could do the trick is to hook up the G terminal on the signaturestat to the W terminal on the Harmony II board. Since this is a cooling-only system, I wager that such a setup could trigger the fan and the zone damper as needed. Presumably, the Harmony II would also not allow cooling and heating to occur at the same time, so it would lock out the "fan program" running over the W port automatically.

As for whether carrier has the same thing or not, I cannot say. It wouldn't surprise me given how much private-labeling Lennox engages in on the controls side. Your company, white rodgers, and others seem to supply them with all their thermostats and it would not surpise me if zone controllers like the Harmony II were simply tweaked versions of extant solutions.

From the little I have read, the infinity control system is fascinating, powerful, easy to retrofit into extant homes (but only if you only stick to carrier gear), and utterly proprietary. Between the 4-wire bus, the adaptive zoning/air velocity, etc. the carrier system makes the other control implementations look primitive by comparison. But it only works for carrier units, so I can shelve that idea.

Thanks for the reply!

Unfortunately, it confirms my fears.

Well, it's worth a look into how the controller and the Harmony II board communicate with each other. If that bus architecture is as primitive as all the other connections, perhaps it is possible to splice in a fan program from the signaturestat that would turn on "continuous fan" on the basis of a fan programmed into the signaturestat.