Honeywell AUTOMATIC CONTROL SI Edition User Manual

ENGINEERING MANUAL OF AUTOMATIC CONTROL
CHILLER, BOILER, AND DISTRIBUTION SYSTEM CONTROL APPLICATIONS
293
Variable Speed Pump Control......................................................... 353
Decoupled Variable Speed Pump Control, Direct Return ........... 353
Pump Speed Valve Position Load Reset .................................... 355
Balancing Valve Considerations ................................................. 357
Balancing Valve Effects .......................................................... 357
Balancing Valve Elimination.................................................... 357
Differential Pressure Sensor Location Summary........................ 357
Pump Minimum Flow Control...................................................... 357
Decoupled Variable Speed Pump Control, Reverse Return ....... 358
Hot Water Distribution Systems........................................................... 358
General ........................................................................................... 358
Hot Water Converters...................................................................... 358
Hot Water Piping Arrangements...................................................... 359
General ....................................................................................... 359
Primary-Secondary Pumping ..................................................... 360
Control of Hot Water Systems......................................................... 360
General ....................................................................................... 360
Modulating Flow Control ............................................................. 360
Supply Hot Water Temperature Control ...................................... 361
Supply Hot Water Temperature Control with Flow Control.......... 361
Hot Water Reset ......................................................................... 361
Hot Water Converter............................................................... 361
Three-Way Valve .................................................................... 364
Coordinating Valve Selection and System Design ...................... 364
Hot Water Control Method Selection .......................................... 364
Chilled Water Distribution Systems ..................................................... 364
General ........................................................................................... 364
System Objectives ...................................................................... 365
Control of Terminal Units ............................................................ 365
Dual Temperature Systems ............................................................. 365
Changeover Precautions ............................................................ 365
Multiple-Zone Dual-Temperature Systems...................................... 365
Steam Distribution Systems and Control............................................. 366
Introduction ..................................................................................... 366
Advantages of Steam Systems Vs Hot Water Systems .................. 366
Steam System Objectives ............................................................... 366
Properties of Steam ............................................................................ 366
Steam System Heat Characteristics ............................................... 367
Steam Pressure, Temperature, and Density ................................... 367
Steam Quality ................................................................................. 367
Steam Distribution Systems ................................................................ 368
Steam Piping Mains ........................................................................ 368
Steam Traps .................................................................................... 368
Pressure Reducing Valve Station.................................................... 369
Types of Low Pressure Steam Distribution Systems....................... 370
One-Pipe Steam Systems .......................................................... 370
Two-Pipe Steam Systems ........................................................... 370
Types of Condensate Return Systems............................................ 370
Variable Vacuum Return Systems................................................... 371
Control Principles for Steam Heating Devices..................................... 371
General ........................................................................................... 371
Modulating Steam Coil Performance .............................................. 371
Oversized Valve .......................................................................... 372
Correctly Sized Valve .................................................................. 372
Supply and Return Main Pressures ................................................ 373
System Design Considerations for Steam Coils ............................. 373
Low Temperature Protection for Steam Coils .................................. 373

Honeywell AUTOMATIC CONTROL SI Edition Specifications

General

Brand	Honeywell
Model	AUTOMATIC CONTROL SI Edition
Category	Control Systems
Language	English