Motor damper control

danw said:

I don't know what 'qw' is.

I'd say the easiest way is to drive the damper with a damper motor that has a 4-20mA input.

Use a temperature sensor as input to the PLC and vary the position of the damper by PID, if it's a setpoint, or by comparison or look-up if air flow has arbitrary control points.

If you don't already have the PLC, single loop controllers do this as a package, presuming you want to control temperature to a setpoint (which might not be the case).

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mo_eng said:

when outdoor air tempreture becomes 24 c or lower the economi9zer system shall be actived. in the case , the fresh , return and exhast air damper shall be proportionaly controled by mixed air tempreture sensor(pt1000)to achive mixed air tempreture sensor wich is 17 c.
at first how can i defined %qw0(analog output to motorize damper)?
i think %QW0:= A (%MW0)^2 + B IN THIS CASE MW0=IW0 AND IW0 IS ANALOG INPUT FROM PT1000
IF THAT RIGHT HOW CAN I DETERMINE A AND B (CONSTANT VALUES)?
my plc is twido (tele) and my motorize damper is siemens

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tripper said:

you have just described a standard ahu (air handling unit) with economy cycle and oa lockout. There are many ddc or bms or even standalone controllers already progammed for this, might save u time & money.

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