Clients/Laguna/emails/.raw/2026/february/FW_UF_Refinement_Notes_1212026.md

—Mason Radke —Autosys, LLC From: Mason Radke <mason@autosysnet.com> Date: Wednesday, January 21, 2026 at 8:08 PM To: Nichols, Jerry <jenichl@countyofsb.org>, Kevin Seifert <kevin@autosysnet.com> Subject: UF Refinement Notes 1/21/2026 Control System Refinement – PID Tuning, Backwash, and TMP Protection Today was a focused and highly productive control optimization session centered around improving PID performance, loop coordination, and backwash reliability while preventing nuisance TMP alarms and protecting equipment. Major Themes * Improved measurement resolution and control fidelity * Faster and more responsive PID behavior * Better coordination between pressure and flow loops * Stabilized backwash and backpulse behavior * Reduced false high TMP alarms * Smoothed transitions and protected mechanical systems ________________________________ Completed Work PID & Loop Improvements * Updated PV for CONV_PID_N145_60 (P35-4 PID) from integer to float for higher resolution control * Switched P35-4 PID from Dependent → Independent mode for finer tuning * Reduced P35-4 update time from 0.5s → 0.1s for faster response * Retuned FIC-3520-4 PID to P: 0, I: 0.01, D: 0 and monitored trends for overshoot/undershoot * Added 50 GPM deadband to prevent unnecessary pump hunting near setpoint * Adjusted unit net flow setpoint from 875 → 825 GPM * Updated PV for CONV_PID_N145_150 (DP loop) from integer to float for improved small-signal control * Updated Backwash Flow PID: * Dependent → Independent * Update rate 0.5s → 0.1s * PV integer → float * Updated Backwash Pressure PID: * Update rate 0.5s → 0.1s * Increased P to 5 to better coordinate with flow loop and prevent TMP alarms ________________________________ Backwash & Backpulse Refinement * Modified Train 4 backwash routine: * Rung 20: Reduced ramp-down rate from 20/500ms → 4/500ms for smoother decel * Rung 18: Changed step range from 40–59 → 40–42 to avoid speed overwrite conflicts * Tuned backpulse startup speed: * Tested 50% → 48% → 44% → returned to 50% after identifying root cause elsewhere * Lowered backpulse flow setpoints progressively for TMP protection: * 1600 → 1400 → 1200 (test condition) * Adjusted TMP protection behavior: * Raised High TMP setpoint 7.6 → 8.0 * Increased alarm timer 7s → 15s to avoid false trips during transients * Tuned both pressure and flow setpoints to: * Prevent false TMP alarms * Allow flow loop time to ramp down before protection trips ________________________________ Testing & Validation Support * Temporarily reduced production cycle time 8 min → 5 min to accelerate backwash testing * Restored production cycle to 8 minutes after validation ________________________________ Additional Logic Enhancements * In ZW4_NP_FLW routine, Rung 6: * Forced lower limit speed to 20% * Ensured proper interaction with Rung 5 logic * Updated SY_3500_4_SP from 35% → 20% to: * Allow lower speeds during high TMP * Match flow PID minimum during chemical backwash * Prevent pressure PID takeover ________________________________ Carryover / To-Do Items 🔧 Engineering Follow-Ups * Expose FIC_8820_4_SP in the HMI to allow adjustable backpulse flow setpoint * Review and improve post-production ramp-down logic to prevent hydraulic hammer * Investigate chemical clean flow control: * P35-4 uses same flow PID as backwash * May require separate tuning or gain scheduling for tighter control during chemical clean —Mason Radke —Autosys, LLC