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GVD-4 Wiring

Is there an internal schematic available for the Field Controls Gas/Vent Damper (Electric) GVD-4? I have seen many online drawings showing pins 1 through 4, but nothing internally. I suspect that there is a motor, relay, manual switch, etc..., but everything I find online about this valve is a block diagram basically showing ONLY the 4 connections. Thank you.


    HVACNUT Member Posts: 5,888
    There is a circuit board in there for switching so there's constant 24v from 1and 4. Other than that it's just a little motor. What's to know? Demand comes in 24v on pin 2. Motor powers damper fully open, then sends 24v out on pin 3.
  • JFredette
    JFredette Member Posts: 3
    Thank you for the feedback. I'm mainly trying to understand the following (since I don't have one of these in front of me to look inside). The motor gets commanded to open up the flapper when there is a call for heat (24V on pin 2), but is that 24V always present during the entire time the furnace is on, or are there components (internal to the damper assembly) that disengage the motor once the damper opens up to a certain point? How does the damper get commanded to close? Is there a relay internal to the damper unit that switches to close the motor? I've looked at some images on line and the flapper appears to be spring loaded, so is there always 24V on the motor when there is a call for heat, then when the setpoint is met, does the flapper simply close because there is no longer power to the motor and the spring pulls the flapper closed? When I've seen videos of the valve opening, it appears that the flapper is being driven entirely by the motor in both directions (open and close).