Hi everyone. We recently built a new house that has a utility room with a bunch of computer and A/V hardware in it. It generates about 1.5 KW of heat continuously. The house is all Mitsubishi Series S City Multi, and has a wall mounted unit in there for cooling. The HVAC design for the house included the ability to dump the heat into the house in winter to offset the need for heating, or put an ERV in bypass mode and change damper settings to bypass the normal HVAC flows and dump heat outside (with make up air coming in) in the summer.
Even though the design included all this, the HVAC contractor could not figure out how to get a carrier damper controller programmed to make these decisions automatically. I am a computer engineer and now am working with the contractor to make the damper controls effective (they have just been manually set to dump heat into the house, with the wall cooling unit set to a high temp to kick in if the normal airflow wasn't cooling the room enough). This is actually pretty easy to implement with a small microcontroller.
I have one question that the HVAC contractor didn't know the answer to. He's calling his supplier, but I thought I'd ask you all. The dampers are carrier DAMPACT45DEG-B units. I get that you apply 24VAC to either the open and the common (to open the damper), or to closed and the common (to close the damper). What no one seems to know (and the documentation is unclear about) is whether or not the power can be applied only during the motion of the damper, or continuously.
I have read stories of dampers being energized continuously and the gears keep spinning and wearing out, but that many new dampers auto shut off when hitting the limits, but we don't know how these DAMPACT45DEG-B units behave. Is it ok to keep 24VAC on the selected contacts, or do I need a timer of some sort to energize them only for a short period of time, and if the latter, how long?
Sorry if this answer is obvious, but we can't find it in the documentation.
Thx
mike
Even though the design included all this, the HVAC contractor could not figure out how to get a carrier damper controller programmed to make these decisions automatically. I am a computer engineer and now am working with the contractor to make the damper controls effective (they have just been manually set to dump heat into the house, with the wall cooling unit set to a high temp to kick in if the normal airflow wasn't cooling the room enough). This is actually pretty easy to implement with a small microcontroller.
I have one question that the HVAC contractor didn't know the answer to. He's calling his supplier, but I thought I'd ask you all. The dampers are carrier DAMPACT45DEG-B units. I get that you apply 24VAC to either the open and the common (to open the damper), or to closed and the common (to close the damper). What no one seems to know (and the documentation is unclear about) is whether or not the power can be applied only during the motion of the damper, or continuously.
I have read stories of dampers being energized continuously and the gears keep spinning and wearing out, but that many new dampers auto shut off when hitting the limits, but we don't know how these DAMPACT45DEG-B units behave. Is it ok to keep 24VAC on the selected contacts, or do I need a timer of some sort to energize them only for a short period of time, and if the latter, how long?
Sorry if this answer is obvious, but we can't find it in the documentation.
Thx
mike
source https://hvac-talk.com/vbb/showthread.php?2224169-Damper-question&goto=newpost
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