Hi guys,

As the title says, the aim of this project is to control the temperature of a room, using a ducting damper actuator, which will open and close using relay switches. I have a cold air source and the aim is to have the actuator open and close in relation to the inside room temp, for cooling.

I will list the components i have purchased to work with below,

So the actuator i brought is a 24vac three position with potentiometer.
https://www.buildingtechnologies.si...s-for-hvac-applications/pages/gdb132_01e.aspx

For the temperature control and relay switches, (230vac)
https://www.elitechonline.co.uk/STC-1000

Power supply:

DC 24v 3a 75watts

I do realise the parts i have purchased may not be compatible, can anyone tell me if it's safe, or even possible to wire my 230vac temp controller switch to mains, and run the 24vac actuator from my 24v DC power supply?

Also, i am having trouble even testing the 3 position actuator. From what i have read, i think 24v DC should work for power.
The actuator has 6 wires in total, 3 of which is for a built in potentiometer.
So, i am connecting the return (negative wire) permanently to negative 24v and touching one or both positive wires to the 24v power, but no movement from the actuator (just faint clicking noise like its trying to move).
Do i need to wire the potentiometer circuit for it to work?

As you can probably tell my knowledge on this is limited, so any advice appreciated, Thanks

 

At the very least you should be using a 240 to 24VAC transformer

 

From what i have read, i think 24v DC should work for power.

Where did you read that? If the actuator is rated for AC, it's not surprising it won't work on DC.

 

At the very least you should be using a 240 to 24VAC transformer

And a circuit would be useful. I do not think this project is for your experience.

 

ok, sounds like the dc power supply probably won't work. I might have read somewhere that the simple 2 wire actuators generally run on DC but im not sure.
what kind of 24vac to 230vac transformer would suit this?

i need to work out how this actuator can be powered before planing a circuit.

maybe i can find a 230vac 2 wire actuator,this could be easier

 

maybe i can find a 230vac 2 wire actuator,this could be easier

Don't see how. The actuator presumably will need to be driven in two directions, which would normally require a DC type if it has only two wires.

 

that makes sense, some damper actuators have spring return, so only have to open i guess


this wiring diagram on page 2,
https://www.belimo.eu/pdf/e/LM24A_1_3_en.pdf

seems you can actually wire the 3-position ones to just open/close

thats why i thought a DC supply would work for this.

 

What I see is one set of instructions to cover all of the versions that the company sells. So the very first step is to examine the whole part number, since the letters following the number tell which particular version it is. And that matters a great deal, since some versions will run on 24 volts DC while others will work with 230 volts AC, which would destroy the model that runs on DC.
THEN, consult the drawings on page 2/2 and find the circuit that matches your model. At that point we can offer some useful help. Until the actual model number is known all the comments are purely guesses.

 

My read here on your motor, starting with your motor is you have a GDB132.1E
Rotary air damper actuator, AC 24 V, 3-position, 5 Nm, 150 s, potentiometer. This data sheet covers your motor and a few others in the family. The GDB132.1E is in the linked data sheet and is a three position control 24 VAC Motor. It does include a 1.0 K Ohm feedback potentiometer which is useful if you want do display shaft position or feedback shaft position to a controller. The AC 24 Volt power is +/- 20% @ 2 VA / 1 Watt so you really don't need much power at 24 VAC. Looking at the data sheet I am not seeing exactly how we get 3 position control. It has to be in there somewhere.

The temperature controller you are looking at seems to be a basic on and off controller. I would have thought you would want a proportional controller with a voltage or current range out and went with a modulator type motor which positions based on a voltage (analog) signal out from a PID controller. Anyway I do not see the controller you picked as a solution.

Years ago when I did system design like this I liked Honeywell 120 VAC motors which took a 4 to 20 mA loop signal from a PID temperature controller. Honeywell Actionator Motors were what I liked.

Ron

 

I went to the data sheet that covers the whole series and followed the link for your device. It certainly looks like it uses the external pot to determine the setpoint. I found that diagram in DataSheet N4634, on page 4 of 6. That also has a description of the functions of each of the wires in the cable, by color code. It is not totally clear how that gives you a three position mode, though.

I am presuming that your goal is to have this thing open a damper for cooling air to hold some set temperature, closing the damper when that temperature is reached and then opening it again as the temperature rises. The device may possibly also be able to constantly adjust the damper to keep the temperature constant. But it might not include that option, the data sheet is not clear on that part.

 

should have linked the proper data sheet, thanks for finding that.
Here is some pics of the parts i'm trying to use..




Trying to learn why i can't use a DC input for actuator, looks like a fairly simple switch.
Do you think its possible there are rectifier diodes to convert AC to DC in the actuator circuitry?

Can you recommend a cost effective AC transformer?
this is best i can find so far,

also, i know its a bad idea to put 230v through the actuator.
could someone please clarify if the temp controller (20A relays) isolates the 230v mains power from the 24vac actuator?

 

ideally i would like to use the 3-position feature, so my cold air intake will have
1.closed position - when temp is to cold
2.Half way -resting position when not powered
2.Open position -when temp is to hot

The problem is, im not sure how the actuator actually responds yet.

first step is getting the actuator to move before i can figure out the correct wiring for temp controller

 

What is confusing to me with the pictures here is that in the data sheet there are shown polarity signs, indicating that you could indeed use DC to power the system, but that it is polarity sensitive. But usually the power requirements of a control system like this are not nearly so critical as to demand a regulated DC power source. Typically they will work well with supplies between 22 and 28 volts that have rather poor regulation. So if you go back to that data sheet, I think that your device does include polarity signs. And it looks like that EllTech device is intended to use mains power, from what I see in the photo. More later, got to leave now.

 

Here is how I would try and get started. You are going to need a 24 VAC power supply and as mentioned the voltage is not critical so all you need is a mains to 24 VAC transformer. The 24 VAC is +/- 20%.

Using the diagram in the data sheet page 4 of 6 connect one leg of the 24 VAC to #1 G Red. Connect the other 24 VAC line to #6 Y1 Purple the motor should rotate clockwise next alternate from #6 Y1 Purple to #7 Y2 Orange and the motor should rotate counter-clockwise. Once you get CW and CCW working you can use an Ohmmeter and look at the potentiometer output using P1, P2 and P3, white /red, white /blue and white /pink. Those are covered in the data sheet.

Looking at the inside the positions of the auxiliary switches should allow positioning as to where they open and close based on the motor position, do they?

Ron

 

What is confusing to me with the pictures here is that in the data sheet there are shown polarity signs, indicating that you could indeed use DC to power the system, but that it is polarity sensitive. But usually the power requirements of a control system like this are not nearly so critical as to demand a regulated DC power source. Typically they will work well with supplies between 22 and 28 volts that have rather poor regulation. So if you go back to that data sheet, I think that your device does include polarity signs. And it looks like that EllTech device is intended to use mains power, from what I see in the photo. More later, got to leave now.

yes, i wired the temp controller to mains, and used the multi meter to check for voltage through the the relay switches circuit. the mains power is isolated from the switches, so i think that means i can safely use a 24vac tran for powering that circuit.
i have another potentially stupid question now...
Could i just rum the 110/230vac temp controller from the 24vac? Is this dangerous?

 

Here is how I would try and get started. You are going to need a 24 VAC power supply and as mentioned the voltage is not critical so all you need is a mains to 24 VAC transformer. The 24 VAC is +/- 20%.

Using the diagram in the data sheet page 4 of 6 connect one leg of the 24 VAC to #1 G Red. Connect the other 24 VAC line to #6 Y1 Purple the motor should rotate clockwise next alternate from #6 Y1 Purple to #7 Y2 Orange and the motor should rotate counter-clockwise. Once you get CW and CCW working you can use an Ohmmeter and look at the potentiometer output using P1, P2 and P3, white /red, white /blue and white /pink. Those are covered in the data sheet.

Looking at the inside the positions of the auxiliary switches should allow positioning as to where they open and close based on the motor position, do they?

Ron

Might be wrong, but the data sheet says no auxiliary switches for my model No. and i would open the unit up, but it has some tamper proof screws
When i get a 24 vac transformer, i can test the operation that way without opening the actuator.

Thanks for your help guys

 

Might be wrong, but the data sheet says no auxiliary switches for my model No. and i would open the unit up, but it has some tamper proof screws
When i get a 24 vac transformer, i can test the operation that way without opening the actuator.

Thanks for your help guys

OK, I was merely speculating you had the aux switches. Once we see how CW & CCW rotation goes we can move along from there.

Ron

 

If the actuator works when connected as in post #14 then you can use the temp controller that you have with it's isolated contacts to operate the motor, using the connections that the post describes. But you will need to know which direction drives cold open and which direction closes cold air closed. AND, I am thinking that the controller qould work with DC, although the motor may need AC. So that power supply may be excess for the project requirements.
AND, I am thinking that the potentiometer connection may be an input, not an output. But it is not totally clear about that.

 

I managed to find something, looking at this data sheet seems to provide more data.

https://www.downloads.siemens.com/download-center/Download.aspx?pos=download&fct=getasset&id1=18318

While I don't quite get the Siemens terminology as to 3 position the actual connection diagrams in Section 9 actually make sense. Section 9.3 shows the actual connections on page 29 of 34.. This also fits with the CW and CCW lines mentioned earlier.

The potentiometer looks to be an output to me where we place a DC voltage across the pot and from the pot wiper get an output voltage proportional to the damper position.This gets used a feedback for some applications.

Anyway the data sheet I linked to while having much of what we already knew seems to have much more stuff in it.

Ron

 

I think that the adjustable switches can set the motion limits as the thing is driven one way or the other. BUT that is not obvious. Probably best to try what I suggested in post#18