Sequence Of Operation:
This controls the AHU supply duct static pressure by modulating the fan speed via a variable frequency drive.
Current Value Chart:
The measured static pressure(STP) strip chart is shown that records each minute the supply air duct static pressure and its setpoint during the previous 60 minutes.
Analog Gauges: Gauges are provided on the central monitoring panel that display: Supply duct static pressure(STP), fan motor frequency(Hz), fan motor voltage(VAC), and the controller output(CO) value to the VFD.
System Chart:
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Controller Status: A 5-state status pilot light is included for the local controller, shown inside this controller's diagram. 1.) Static Pressure Setpoint(SP) - When this radio button is checked it the static pressure setpoint is available for change. 2.) Proportional(P) Value - When this radio button is checked the value is available for change. 3.) Intergral(I) Value (repeats/minute) - When the checkbox is un-checked the integral is is ignored. When the radio button is checked the value is available for change. 4.) Derivative(D) Value - When the checkbox is un-checked the derivative value is ignored. When the radio button is checked the value is available for change. 5.) VFD Demand(CO): 0 to 100% - When this radio button is checked it overrides the controller output (CO) and selects a manual mode. Choose the radio button for desired value to adjust. Select the increment, then use the ![]() ![]() |
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AHU Supply Duct Static Pressure Control - Strip Chart | |
This example continuosly records the supply duct static pressure(STP), variable frequency drive values (Hz & VAC), PID controller output value(CO) at the current minute and during the previous 100 minutes. Simulation: random values updated every 2 seconds (equals 1 minute). |