Presentation by Clifford T. Johnson, PE, Control Systems Engineer Loop Diagrams Chapter 7 Honeywell Chapter 3 Instrumentation and Control Systems Documentation Loop Diagrams are most important for technicians Presentation by Clifford T. Johnson, PE, Control Systems Engineer Today Instrumentation ELC-213

Control Modes, Proportional. Reset & Rate Assignment , Lab & video Loop Diagrams Control Modes, Proportional. Reset & Rate Today Assignment & Lab ELC-213

ISA Definitions These are excepts from the ISA Comprehensive Dictionary of Instrumentation and Control page 168 covering LOOP ISA Loop Definition ELC-213

ICSD Chapter 7 Loop Diagrams A better definition is: A single stand alone device is NOT a loop ICSD Loop Diagrams ELC-213

Instrument Loop Identification Chapter 7, Pg. 141 details The P&ID is where the actual loops are defined and receive their tagging and Loop numbers. The devices are then entered into the Instrument Index, the the specification sheet is created, the IOM is received and it would be at this point that the loop sheet can be developed ICSD Loop Identification ELC-213

left up to the designer and engineer as they see fit Loop Diagram Symbols Instruments ISA symbols are generally used to depict Instruments and control devices with the addition of terminals or ports Other devices Tanks, piping, etc are left up to the designer and engineer as they see fit ICSD Loop Symbols ELC-213

Energy Supply Electrical, Pneumatic, and other requirements for operating the instrumentation and control devices must be clearly identified by the sources such as electrical breakers and air supplies. Not just what it is, but where is it coming from. ICSD Loop Energy ELC-213

Instrument Action ICSD Instrument Action ELC-213

Loop Diagram Field Area ICSD Loop area ELC-213

Loop Diagram most common ICSD Loop Diagram ELC-213

Loop Diagram complex ICSD Complex Diagram ELC-213

You must show solenoid operation Loop Diagram SIS You must show solenoid operation Download from Resources and Fill in Tags, correct the symbols as necessary, Show actual wiring with numbers and colors and Fill in Title Block Lab SIS Loop Sheet ELC-213

Loop Diagram for a fieldbus ELC-213

Summary: Loop Diagrams Next to the the P&ID, the Loop Diagram (or Sheet) is the most Important document for the Instrument Technician. Do not let the contractor create the loop sheets. He does not have the proper experienced people to do a good job. There are a few good Instrument Database software applications that make the job easier with fewer errors Properly developed they will greatly assist the technician to troubleshoot a control problem. Cliff T Johnson, PE, Control Systems Engineer Instructor, CPCC, ELC-213 & PCI-162 Summary Loop Diagram ELC-213

Honeywell Chapter 3 Modes of Control ELC-213

Honeywell Chapter 3 On-Off ( HVAC) ELC-213

Honeywell Chapter 3 Propotional Band 100% ELC-213

Honeywell Chapter 3 Propotional Band 20% ELC-213

Honeywell Chapter 3 Propotional Band 200% ELC-213

Honeywell Chapter 3 Reset (Integral) Action ELC-213

Homework ASSIGNMENT Web Link Find an example of a Loop Diagram on the web, email web page LINK only to me, do NOT email images or web pages All Emails Subjects and File names must have Subject:Your last Name-Subject-Assignment Date (AD) Email subjects Ex: Johnson-LoopLink-AD File name Ex: Johnson-Loop- AD.vsd You will lose 1-3 points for incorrect subject Subjects Assignment ELC-213

The End End Instrumentation ELC-213