Jump to content
NOTICE / HINWEIS: iOS 18 Update and Today Widgets ×

No VDC tension mesured between + and -


Recommended Posts

Hi,

I bought a Shelly Plus 0-10V Dimmer which I want to use with a variable frequency drive (VFD) to control the rotation speed of an asynchronous motor.
https://www.amazon.com/CNweiken-Variable-Frequency-Converter-Regulation/dp/B09XM69TYT?th=1
The VFD accepts an input signal between 0 and 10 VDC which proportionally varies the motor's rotational speed.

In my installation, the Shelly is powered in accordance with the instructions with a 220VAC voltage on the L and N terminals. It is well paired and connected to my Wifi.
I access and control the Shelly without difficulty both via the http interface and Home Assistant.

Surprisingly when I activate the Shelly and use the variator at 20, 50, 75% no VDC voltage is measured with a multimeter between the + and - terminals
I would have expected to find a voltage between these 2 terminals, I measure tiny values, ex 0.25 VDC, but not the expected values Ex: 5 VDC with the dimmer set to 50% or 10VDC with 100%

Can you help me understand this phenomenon?
With the dimmer set to 50% I should be able to measure 5VDC between these terminals, right ?
Is it correct to think that the Shelly provides an output between 0 and 10 VDC between the +/- terminals like an adjustable VDC power supply?

Thx 
Stef

Link to comment
Share on other sites

  • Members
Posted (edited)

The Shelly plus 0-10V Dimmer has a passive 0-10V output. It delivers no voltage, but a pulse wide modulated impulse train. Most LED drivers use PWM 0-10V inputs which deliver the necessary voltage of 10 V DC. To get an active 0-10V PWM output, you may use an additional Shelly Add-On plus:

IMG_1078.thumb.jpeg.423786e0ca21cb2250437243116ed639.jpeg

 

The 4,7kΩ resistor improves the linearity. It may be omitted if this tradeoff is negligible.

Edited by thgoebel
Link to comment
Share on other sites

  • 2 weeks later...
On 6/9/2024 at 9:48 PM, thgoebel said:

The Shelly plus 0-10V Dimmer has a passive 0-10V output. It delivers no voltage, but a pulse wide modulated impulse train. Most LED drivers use PWM 0-10V inputs which deliver the necessary voltage of 10 V DC. To get an active 0-10V PWM output, you may use an additional Shelly Add-On plus:

IMG_1078.thumb.jpeg.423786e0ca21cb2250437243116ed639.jpeg

 

The 4,7kΩ resistor improves the linearity. It may be omitted if this tradeoff is negligible.

This solution seems so smart! Great! I have been searching for months for something "easy" like this. I will try as soon as possible. Do I have to configure something specifically by shelly app on Add-on side?

Link to comment
Share on other sites

  • 2 months later...

Hi Guys,

@thgoebel, is it mandatory to use a 4,7k resistor and to strap VREF OUT and VREF + R1 OUT on the shelly dimmer 0-10v?

@Stef, what about the control of your variable frequency drive (VFD) with a Shelly Dimmer 0-10v to control the rotation speed of an asynchronous motor? Is it working? Could you detail the connection between + and - of the Shelly and the AI1, ACOM and 10v of the inverter?

Best regards.

Link to comment
Share on other sites

  • Members
Posted (edited)

No, it is not mandatory to provide a 3,3kΩ terminating resistor (parallel connection of 10kΩ and 4,7kΩ) for the output. This helps to linearise the output voltage in the case it’s transposed as voltage in the external curvaceous, not as PWM signal. In every case you need a PWM signal only , the internal 10kΩ resistor in the Add-On plus (terminal Vref+R1 Out) is sufficient. 

Edited by thgoebel
Link to comment
Share on other sites

OK, many thanks thgoebel.

Is there an idea for connecting the shelly dimmer to an inverter's input external speed control like this one? it's for adjusting the power consumption of a swimming pool pump (1.9 kW/h at 50 Hz!!! 😞

image.thumb.png.089785293fbc3123a4f8d03b1c906582.png

+ pin on the shelly must be connected to 10V? AI1? or ACOM? on the inverter

- pin on the shelly must be connected to 10V? AI1? or ACOM? on the inverter.

First I tried to use the Add-On with your diagram by connecting (+ Shelly Dimmer) to (AI1 inverter) and (- Shelly Dimmer) to (ACOM inverter): it works... but something seems to be wrong: the input voltage measured between AI1 and ACOM varies from 0v to 5.6v (and not up to 10vcc), and the frequency displayed on the inverter from 0 Hz to 20-30 Hz, and not very steady, even if I do not change the slider position of the dimmer into the Shelly App.

Then I tried to use only the shelly without the Add-on Plus by connecting (+ Shelly Dimmer) to (10V and to AI1 inverter) and (- Shelly Dimmer) to (ACOM inverter) because it seems to me very close to your diagram with the Add-On. It doesn't work: 10 vcc whatever the slider position of the Shelly dimmer into the Shelly App...

Best regards.

 

Link to comment
Share on other sites

  • Members

The inverter has a (passive) 0-10V control input, but NOT a PWM input! In this case I would recommend a Shelly Dimmer 0/1-10V PM, which delivers a quite smooth DC voltage between 0-10V. This control voltage depends on the dimming level (0-100%) which is adjusted with WebUI, Shelly Cloud or a Smart Home application. Terminal „minus“ of Shelly has to be wired with ACOM of the inverter; terminal „plus“ of the Shelly goes to AI1 of the inverter.

IMG_1366.thumb.jpeg.c5869eac07dec6541d5dbab512eb7333.jpeg

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...