Laserfiche WebLink
x St¢ttiors Pressure Conlrol <br />A. General: Provide the Operalo€s with the following options for pressure control; <br />MANUAL PRESSURE CONTROL: Provide a RTtz panel 2 -way selector swvitch <br />(h1ANi AUTO ➢), hr. MAN anode. the I'LC Pit) Loop will use [lie POTFNTIOMFTFR input <br />vsa] vo Lis Ilse discharge pressure setpoint to maintain. "l`Itis O -5k ohm PO'f''LN`FIOME'Cl:R (on <br />the [ace of the RTU) signal will be converted to a 4 -20 mA signal ushig an AGM signal <br />b,ulartcr /converter. The 4 -20 mA signal will be an anatog input into the PLC 1 /0 and then he <br />settled into the logic with limits of 60 -90 psi 1nr cod to end tutrts of the potentioanter. This <br />will prevent an operator 0 -om dialing in an unacceptable value for discharge pressure <br />setpoint. Thiw manual mode shall override any AUTO setpoin't valve. <br />2. AUTO PRESSURE CONTROL / PLC: When the pressure scilpoiant switch is placed in <br />AU'TL)„ the PLC shall use an internal PIII loop to control the dkofiarge pressure to match the <br />auto pressure setpoint value which may be entered into the PLC via operator entry through <br />SC'ADA car H:N41 lwith operator access control). <br />AUTO PRESSURE CONTROL / ABB LOOP CONTROLLER BACKUP: Under normal <br />conditions, the PLC signal to the VFD will "pass through" the ABB single loop controller. <br />In the event this input control signal is "lost ", tlae ABB single Loop controller will use all <br />internal PID Corxtrol to oporate in BACKUP MODE using a ,cparatety provided pressure <br />signal to maintain the "active" pressure setpoint. The ABB single loop controller will <br />continuously display the pressure sel.point and discharge pressure "active" values. <br />4. The VFD shall always follow the output signal from the PLC in Ai TO PLC and follow the <br />ABB single letup controller in AUTO/ABB CONTROLLER and P1D BACKUP modes. <br />X1 Booster Punms Flow Monitoring <br />A. Harrclwired Functions <br />I. \one. <br />B. PLC" Functions <br />1. MO Ili liar Lhe bnosuI• PLanp dischrtrge flow meter and 'generate a totalized flow (I 000s of cubic <br />feet) capable of ra miarinium of art least eight significant nannber& <br />C. IIMI Functions <br />1. Display both current 11ow and totalized flow. <br />X11 Bvimss Mode <br />A. Hardwired Functions <br />City of Santa Ana RFP 15 -105 <br />261218 <br />