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Fan motor ramp up - Printable Version

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Fan motor ramp up - KoBra - 14.02.2022

I am trying to control fancoils with 0-10V EC motors. There is no actual load on the actuator but they make noise if i apply from one to another moment 100% (10V) to the controller. Basically i have the fan speed where i need to go to, but i need a ramp up/down script (of FB editor building block)

so if i change from 0>10V i must ramp up from 0>10V in 10 seconds for example. Anyone an idea how to do this in a convenient way? 

(i searched the forum but it seems no one ever dealt with this issue)


RE: Fan motor ramp up - Dré - 14.02.2022

maybe this is wha tyou are looking for?

This example will dim 3 lights from 0% to 100% in 10% steps with 0.2 seconds delay between each step. You can adjust the step/delay as needed and also add new group addresses to the list.


RE: Fan motor ramp up - KoBra - 16.02.2022

(14.02.2022, 18:31)Dré Wrote: maybe this is wha tyou are looking for?

This example will dim 3 lights from 0% to 100% in 10% steps with 0.2 seconds delay between each step. You can adjust the step/delay as needed and also add new group addresses to the list.

Thanks, that is already something.

But i tried and it just goes from 0-100 in a loop. (sorry noob in scripting)

Basically i calculate the set point of the fan speed based on room temp, offset to target and a minimal fanspeed. The target is adjusted when the room goes from Standby to Comfort in KNX but it can happen during a mode change the fan goes from 0-100% at once. I send this on address 2/1/9 but if i send out the setpoint at once (lets say 100%) the fans don't like the torque the electric EC motor makes. As the analogue output sends 10V at once towards the FCU

To avoid the big starting torque i need to ramp up and down the fan to make sure the motors last longer where the setting 
step = 1
delay = 0.1
works perfectly but i just don't want a loop   Wink 

When turning off it is the other way around. If a fan would be at 100% and go of (but this is a much rarer case) you could get a spike in the control voltage as the motor becomes a generator at once.


RE: Fan motor ramp up - admin - 16.02.2022

Event script that gets the target level and adjusts the output object in small steps. Adjust as needed:
Code:
output = '1/1/4'
step = 5
delay = 0.5

target = event.getvalue()
current = grp.getvalue(output)

if target == current then
  return
end

while true do
  if current < target then
    current = math.min(current + step, target)
  else
    current = math.max(current - step, target)
  end

  grp.write(output, current)

  -- stop when target is reached
  if current == target then
    return
  end

  os.sleep(delay)

  -- stop when targed changed, another script is running
  if grp.getvalue(event.dst) ~= target then
    return
  end
end



RE: Fan motor ramp up - KoBra - 16.02.2022

(16.02.2022, 07:12)admin Wrote: Event script that gets the target level and adjusts the output object in small steps. Adjust as needed:
Code:
output = '1/1/4'
step = 5
delay = 0.5

target = event.getvalue()
current = grp.getvalue(output)

if target == current then
  return
end

while true do
  if current < target then
    current = math.min(current + step, target)
  else
    current = math.max(current - step, target)
  end

  grp.write(output, current)

  -- stop when target is reached
  if current == target then
    return
  end

  os.sleep(delay)

  -- stop when targed changed, another script is running
  if grp.getvalue(event.dst) ~= target then
    return
  end
end

Thanks! Works perfectly! Would recommend to note this somewhere as a standard script for EC fancontrol (0-10V controlled fans)


RE: Fan motor ramp up - admin - 16.02.2022

A proper solution would be to use an analog output that has a transition time setting. Reactor LMs with analog outputs have this out of the box.


RE: Fan motor ramp up - KoBra - 16.02.2022

(16.02.2022, 08:45)admin Wrote: A proper solution would be to use an analog output that has a transition time setting. Reactor LMs with analog outputs have this out of the box.

I agree but in this case this functioniert is Not available on the AO module.
I also use this Funktion to send a Control percentage by modbus to LG AHU supply air controllers.