VisionPRO IAQ Discharge Air Temperature Sensor

[garya505]

Does anyone has experience with the Discharge Air Temperature Sensors on the VisionPRO IAQ? Depending on what Honeywell doc you look at, it uses either the C7735A1000 (2-wire) or C7835A1009 (3-wire), or maybe either one. The odd thing is, the C7735 would go to the DAT sensor connections on the EIM like it does on the Prestige IAQ, but the C7835 is a 3-wire Enviracom connection so it would go on the Enviracom 1-2-3 terminals. This really doesn't make sense, unless the VisionPRO IAQ is smart enough to look for either one.

Lookin for a Honeywell VisionPRO IAQ DAT sensor expert here ... :det:

[SoFlaDave]

Well the 3 wire sensor will be sending a unique communication signal that the stat should pick up on. Basically the 2 wire signal is getting sent through the EIM and 3 wire is getting sent directly to the stat. That being said, I have not used the 3 wire sensor yet.

[garya505]

Well the 3 wire sensor will be sending a unique communication signal that the stat should pick up on. Basically the 2 wire signal is getting sent through the EIM and 3 wire is getting sent directly to the stat. That being said, I have not used the 3 wire sensor yet.

Yeah I'd like to get some more detail on that. From reading some docs, it appears that the 3-wire C7835 was mostly used for zoning applications in the past, where you need to know when preset high and low limits are exceeded. All the zoning panels seem to have the 3-wire Enviracom interface. I suspect that the 2-wire C7735 is newer, and intended for connection to the EIMs on the Wireless FocusPRO, VisionPRO IAQ, and Prestige IAQ (which can't use the 3-wire C7835). However, I see that it's also used in some zoning setups. And the VisionPRO IAQ seems work with either one, so it's not real clear.

[garya505]

What I found out so far is that the C7735A1000 is used on all the Honeywell HZ model zoning panels. I haven't found the C7835A1009 used much, yet.