06062017 Cascade LevelFlow Loop Tank Fill Level set

06/06/2017 Cascade Level/Flow Loop Tank Fill Level set point L LIT LC 1 1 Flow set point FC 2 H 30. 0" H FIT L 2 I FCV P 2 FE 2 Cascade Control – Block Diagram Slave Set Point Final Control Element Process Flow Secondary Master Controller (Primary) Master Set Point Controller Output Slave Controller (Seconary) Variable Measurement Controller Output Level Primary Variable Measurement PITH 2 UR Notes: 1. UR – Paperless Chart Recorder 2. YIC – Loop Controller 3. PITL – Differential pressure indicator, transmitter measuring level; LIT 4. PITH – Differential pressure indicator, transmitter measuring flow; FIT 4. Tank A and B are open to atmosphere. 5. VFD – Variable Frequency Drive Three Valve Manifold IA 24 Vdc Open to Atmosphere Column FE YIC I P FV 2 1 PITL 1 L H FI SV HV 3 A C 2 HV 4 A 1 HV 5 A HV 2 A HV 3 B HV 4 B HV 5 B HV 2 B C 1 E 2 E 1 Chiller HV 7 Tank A Warm Water 16 Gal. (60 L) HV 1 B Tank B Cool Water 16 Gal. (60 L) HV 6 A VFD VFD HV 8 B HV 1 A VFD HV 8 A P 4 P 1 P 3 P 2 2