# Louver motor control



## mpcxl (Dec 9, 2015)

Can someone please explain this louver motor control to me. It’s controlled by a clothing dryer.


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## trentonmakes (Mar 21, 2017)

Is that some type of relay???

Likely open and closes the exhaust vent when dryer is on/off

Sent from my LG-K550 using Tapatalk


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## Forge Boyz (Nov 7, 2014)

It's a stall motor that has dry contacts on it when it is at certain angles.

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## cmdr_suds (Jul 29, 2016)

Pretty standard HVAC damper actuator. 120VAC to drive open. Spring retrun closed (removal of 120VAC). 90Deg rotation 15 seconds to open, 15 sec to close. Aux switches set at 10deg and 85 deg of rotation. Direction is determined by which side faces up


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## Signal1 (Feb 10, 2016)

It's a line voltage damper actuator that opens the vanes when it receives an output from the dryer. 
The end switch is to prove that the louvers have fully opened to allow the equipment to start.
Most commercial laundry equipment has a terminal strip on the back for these terminations.
I'm assuming this is for make-up air or combustion air.


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## micromind (Aug 11, 2007)

As noted, when voltage is applied (I've seen both 120AC and 24AC models), the shaft will rotate and stay as long as power is applied. 

Even though the motor is locked-rotor, it doesn't burn up. It is designed to operate this way. 24/7 for many years. 

When power is removed, the shaft will spring back.


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## Wirenuting (Sep 12, 2010)

You can double or triple stack them for greater torque.
They can be spring or powered return.
They also have 0-10 volt & 4-20ma positional versions.
The clamping end, u bolt style, on the shaft likes to work loose on dampers over time, it's worse inside air handlers.
They are cheaply made IMHO.

I like the Honeywell modutrol motors, but don't see them installed much anymore.. They cost more but last longer.


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## BrettC (Apr 10, 2016)

micromind said:


> As noted, when voltage is applied (I've seen both 120AC and 24AC models), the shaft will rotate and stay as long as power is applied.
> 
> *Even though the motor is locked-rotor, it doesn't burn up. It is designed to operate this way. 24/7 for many years. *
> 
> When power is removed, the shaft will spring back.


I read somewhere that ceiling fans are actually designed the same way, with very fine motor windings (apparently you can hold a ceiling fan at locked rotor current for a week or more). The inductive reactance creates a high enough impedance that there isn't a lot of current and therefore not a lot of heat (or something like that, my science might be sideways).


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## mpcxl (Dec 9, 2015)

Im confused about the Aux contacts, applied voltage and angle degree.

I get 120 goes to the motor but 120 also to contacts? And I dont understand the degree positioning ( 10 and 85).


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## varmit (Apr 19, 2009)

The contacts are for interlocking other components in the system. Example: A fan runs at full speed when the damper is at "x" degrees open. The fan shuts off when the damper is at "x" degrees open. On some models the contacts are factory jumpered from the actuator line. Others have separate "dry" contacts to allow you to use a different voltage for other controls. Some models also have analog feedback.


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## varmit (Apr 19, 2009)

To explain the reason for this unit in your application, I will assume that this is a commercial laundry with multiple dryers on a common exhaust header.. 

Possible operation: 
The dryer is loaded and started. The drum begins turning and the damper is commanded to open. When the damper gets to its open setpoint, the dryer heat comes on. 

When the drying cycle ends, the heat turns off and the damper closes. The "damper closed" position switch could allow the dryer door to be opened for unloading the dryer. 

A reason for the damper would be to lessen the heat from adjacent dryers, on the same exhaust header, from blowing hot, humid air into the stopped dryer while it was being unloaded and reloaded. The damper would make conditions a little better for the operators since it would lower the heat when the dryer was opened.


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## MDShunk (Jan 7, 2007)

Those Belimo damper motors have gotten really popular over the last 10 years. They're about half the price of the equivalent Honeywell that one would ordinarily use. We have a couple hundred of them at my workplace, and I can't say that they fail at any greater rate than any other damper motor I've had experience with. They take about 10 minutes to change out, assuming the mounting bolts aren't rusted. The bummer is that I deal with about 5 different versions of the same motor. Normally open, normally closed, power open/power close, 120 vac and 24 vdc. Some with end switches, some without. I know there's one with some kind of proportional control, but I haven't had to mess with it yet.


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## mpcxl (Dec 9, 2015)

varmit said:


> The contacts are for interlocking other components in the system. Example: A fan runs at full speed when the damper is at "x" degrees open. The fan shuts off when the damper is at "x" degrees open. On some models the contacts are factory jumpered from the actuator line. Others have separate "dry" contacts to allow you to use a different voltage for other controls. Some models also have analog feedback.


can you explain spec rating for aux contacts. why 0.5 inductive / 3 amps resistive @ 125/250? 

what are the numbers for at the actuator lever? are those degrees?

what does CW stand for and the symbol next to it?

so basically the aux contacts are not needed for operation. how do you know the motor opens to 90 degrees?

sorry for so many questions. Just trying to make sense of this​


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## MDShunk (Jan 7, 2007)

mpcxl said:


> can you explain spec rating for aux contacts. why 0.5 inductive / 3 amps resistive @ 125/250?
> 
> what are the numbers for at the actuator lever? are those degrees?
> 
> ...


Aux contacts on any positioning device are used by other parts of the controlling system to prove the thing is in the position it thinks it is. For instance, the dryers might rope the burner on control through those aux open contacts to only allow the burner to run if the damper open limit switch is happy.

Very common thing on valve control tops. Pump only gets permission to run if the valves it's pushing through have seent feedback that they're open.


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## pjholguin (May 16, 2014)

I have installed thousands of the Belimo damper actuators, they are very popular in the Pacific NW. We would use them when we were contracted to convert pnuematic controls to DDC. Never really had any issues with them.



MDShunk said:


> Those Belimo damper motors have gotten really popular over the last 10 years. They're about half the price of the equivalent Honeywell that one would ordinarily use. We have a couple hundred of them at my workplace, and I can't say that they fail at any greater rate than any other damper motor I've had experience with. They take about 10 minutes to change out, assuming the mounting bolts aren't rusted. The bummer is that I deal with about 5 different versions of the same motor. Normally open, normally closed, power open/power close, 120 vac and 24 vdc. Some with end switches, some without. I know there's one with some kind of proportional control, but I haven't had to mess with it yet.


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## Signal1 (Feb 10, 2016)

> what does CW stand for and the symbol next to it?


Clockwise open, spring return.

If you flipped it over you would see CCW with the little spring icon.


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## Going_Commando (Oct 1, 2011)

mpcxl said:


> can you explain spec rating for aux contacts. why 0.5 inductive / 3 amps resistive @ 125/250?
> .5A inductive gives the contacts some leeway on in-rush current so they don't burn out. Resistive loads don't have inrush current like motors or coils do.
> 
> 
> ...


See blue comments.


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