ReplyOnce closed or open completely they should quit running.
Regular Guest
I have a Carrier Comfort Maker zone system that was installed in my house when it was built in 1997. These are the three wire power open / power close style dampers. When I had the system replaced, I replaced the zone board with a Honeywell HZ432 to accomodate the dual fuel setup, but we left the existing dampers.
In any case, I went into the attic today and heard one of the dampers making kind of a clicking or chirping noise. The system was not running, and hadn't been running for a while.
When I put my finger on the motors in each of the dampers, it felt like they were both running. The noisy one got quiet after I touched the motor. My question is this... do the damper motors continue to run all of the time, or should they time out or have a limit switch, so that the motor isn't running while the system is off or after the damper is in position?
Thanks!
Heath
Professional Member
Once closed or open completely they should quit running.
Professional Member*
I am going to disagree with you but thank you for your comment.Originally Posted by ar_hvac_man
In my opinion, it complete depends on the type of motor.
Motors that control dampers are normally referred to as damper actuators.
While some actuators will run as ar_hvac_man said, some actuators use pancake motors. These motors may keep coils energized 24/7 to keep the same position.
Some actuators have spring loaded fail safes. If it fails it fails closed. These actuators may need to stay energized to keep the position.
I think it really depends on the type of actuator you have controlling these dampers.
If you're too "open" minded, your brains will fall out.
Artificial intelligence is no match for natural stupidity.
Professional Member
Ive been wrong before. At any rate they are 15 yrs old Id have them checked out.
Regular Guest
Finally got up in the attic with a camera. Here are some pictures of the damper actuators. Does anyone know if they're repairable, or am I going to need to have them replaced?
A video, mostly to hear the noise
http://www.youtube.com/watch?v=fbLkr...ature=youtu.be
and a couple of pics
Thanks!
Heath
Professional Member*
It's toast!
The good news is that most brands of damper motors will work with the existing dampers, so no cutting into the duct.
Professional Member*
If you notice, there is a screw between 45° and 90°. That is there for air balancing purposes to prevent your damper from opening to much.
While it is good they did the air balance (and a must) the problem with an actuator like that is when it hits the screw it tries to keep going for a period of time. During this time the cogs on the gears skip and wear out over long periods of time.
The noise you are hearing is the rub of the skipping gears that are now worn out.
You will also notice towards the top you have a fat red button. This button is the gear release. The bar against the screw is to show the current position of the damper.
Push the red button in and hold it. Turn the damper clockwise until that bar is no longer against the screw. Release both the damper and the button. If it still doesn't move but you can hear the rubbing gear cogs you will need to replace the actuator.
If it does move (most likely but may not rotate all the way back to one screw or the other) you have a different problem.
If you're too "open" minded, your brains will fall out.
Artificial intelligence is no match for natural stupidity.
Professional Member*
The root of the problem is that those particular actuators were not specifically designed to be powered all of the time, so they don't have any internal circuitry to keep them from continuously driving against the range stop.
The original zone control panel they were used with would only power them open or closed for a minute or 2, then stop powering them until the next time their position needed to be changed.
Most of the newer add on zone panels power the damper actuator one way or the other continuously.
The newer actuators typically have circuitry built into them to prevent them from driving against the range stop constantly.
Specifically I've had complete success with retrofitting EWC damper actuators on those dampers.
They also give a nice red light/green light indication that they are fully to the closed or open position.
Regular Guest
I was wondering about that. It seemed like a bad design for them to be running continuously. Is there a particular EWC unit that you would recommend that I suggest to my HVAC guy?
I'm thinking he would be more likely to swap the entire damper out, which I assume would cost more - but if I can suggest something to him he's usually open to it.
Heath
Professional Member*
It is the EWC "MRK" motor replacement kit. It comes with mounting hardware for a number of applications, including a bracket that will be needed to secure it to the body of the damper assembly.
Professional Member*
The damper actuators that Carrier has been using for the past several years are modulating and not full power open/close. They take a 24v signal and drive the damper to the needed position and then the 24v is de-energized until another call to re-position. Some dealers have used them on other than Carrier zoning systems and they will work for a time and them burn out.
I only refer to this to make others on here aware of that so they don't install a new actuator only to have it fail. Always be certain of the type of system and controls you are working with.
Regular Guest
Sounds familiar
Thanks for all of the help guys... I think I'll have them replaced with the EWC MRK style if they'll drop out after they reach the open or closed position rather than just sitting there clicking and chirping away.
Heath
Regular Guest
Thanks for the recommendation Mark. The EWCs have been working great for a few days now!
Heath
Professional Member*
Great!
Professional Member
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Last edited by jpsmith1cm; 05-03-2013 at 05:34 AM. Reason: non AOP Pro Member
Professional Member
SurreyStevo
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