Chapter 9 Analog Electronic Controls - ibse.hkibse.hk/cpd/control/ASHRAE_Workshop_Control_WilliamYick...©ASHRAE 1999 9-47 Configuration Process Binary Inputs Status Trip Alarm Binary

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Chapter 9Analog Electronic Controls

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Control I/O

Analog InputTemperature – 100 ohm, 1000 ohm0-20mA, 4- 20mA, 0 – 10 Vdc,

Digital InputOn/OFFPulse

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Control Output

Analog Output0-20mA, 4- 20mA, 0 – 10 Vdc,

Digital OutputOn/OFFPulse

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Application-SpecificElectronic Controllers

Single-zone unit controllersControl of VAV air handlers and packaged unitsControl of multizone air handlersEconomizer enthalpy controlVAV box controllers

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Types of Actuators

Electronic-electricElectronic-hydraulicElectronic-pneumatic

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Hydraulic Actuator

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Single Zone Unit

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VAV System Control

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Chapter 10Digital Controls

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Basic DDC Loop

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Types of Input/Output Points

Analog inputsBinary (digital) inputsAnalog outputsBinary (digital) outputs

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Small Stand-Alone Panel

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System With DataGathering I/O Panels

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Distributed Intelligence

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Two-Tiered Network

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Types of System Software

Network communications softwarePanel operating systemsApplication softwareUtility softwareOMI software

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Programming Languages

Text-based languagesGraphical programmingLadder logic

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Text-Based Programming100 C*** ECONOMIZER OUTDOOR AIR DAMPER CONTROL105 C*** SHUT DAMPER WHEN FAN IS OFF110 IF (FANDPS.EQ.ON) THEN GOTO 510120 SET (0, OADMPR)130 GOTO 1000500 C*** SHUT OFF ECONOMIZER WHEN OAT >65510 DBSWIT (1, OATEMP, 63, 65, $LOC3)520 IF ($LOC3) THEN GOTO 610530 SET (20, OADMPR)540 GOTO 1000600 C*** OUTDOOR AIR DAMPER, N.C., 0 TO 100%610 LOOP (128, MATEMP, $LOC1, 55, 10, 30, 0, 1, 50.0, 0, 100, 0620 MAX (OADMPR, $LOC1, 20)1000 C*** END OF ECONOMIZER CONTROL

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Graphical Programming

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Ladder Logic Programming

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Question & Answer Template

Response32. Is there heating control? (y/n) Yes33. Type of heating control: (select a, b, c or d) C

a. Two-positionb. Modulating with face and bypass damperc. Modulating without face and bypass damperd. Modulating with common heating and cooling

36. What is the heating output with the fan off? (___%) 0%37. What is the heating setpoint? (___°F) 105°F38. Is there an auxiliary two-position output? (y/n) No

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Typical I/O Schedule

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DDC Control Schematic

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Sequence of OperationOccupied modeUnoccupied modeSetback modeFan alarm modeRoom temperature controlDry bulb economizer controlMixed air low limit controlFan alarmFilter alarmFreeze alarm

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Graphical Programming

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Advantages of DDCIncreased accuracyFlexibilitySophisticated control sequencesEnergy managementTrendingAlarm reportingRemote monitoring and controlPreventative maintenanceLower cost in many applications

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Agenda

IntroductionSystem ArchitectureCommunication ProtocolHow to design a systemQ & A

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IntroductionBMS – Building Management SystemIt is used for Monitoring & Control the followings:

1) HVAC System2) Fire Services System3) Plumbing & Drainage System4) Electrical System, 5) Lighting System

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Others Features

Energy Audit SoftwareData VisualizationTotalizationTime SchedulingEvent ProgramRemote AccessLoading Profile

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BMS Role

Manage occupant comfortAlert operators of facility problemsReduce energy usageProtect facility assets

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Design Background & Intent

Central Control and Monitoring System

Centralize Monitoring and Control system to manage a group of building systemsProvide management features for building systems operation and monitoringProvide reporting features to summary the systems status and alarm reportingReduce manpower or providing better service

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Benefits

Lowers Energy Cost

Lowers Operations Cost

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What it doesConnects to major M&E equipment in the building.Automatic operation for routine and repetitive

functions.Reduced operator training time through on screen

instruction and supporting graphic display.Better management of energy cost through energy

management programs.Better management of facility through historical

records.Improved operation through software and hardware

integration of different subsystems such as fire alarm and access control.

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What Customer Wants BMS to Do

Easy to useEasy to installAble to control the building with minimum manpower and energy without risk of customers’ comfort.Open systems and vendor independence“Web interface”

Don’t make me buy software for each userAble to access remotelyKeep me safe from “hackers”

Current technology

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System Structure

The Metasys DistributedThe Metasys DistributedUser InterfaceUser Interface

TCP/IPTCP/IP

N2N2

BACnetBACnetLONLON

Automation Automation EnginesEngines N2N2

BACnetBACnetLONLON

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Network Controller

Building Automation FunctionsAlarm detection/managementSchedulingTrends ReportTotalizationOptimal start/ stopCustom control applicationsEvent program

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Network ControllerBACnet IP (across the network)BACnet MS/TP (field bus standard)Variety of modelsJava Virtual MachineEmbedded Microsoft OSIP “http, soap, snmp, smtp, sntp…”LON (field bus compatibility) Web Services

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BACnet ControllersField Equipment ControllersTerminal Equipment ControllersInput/Output ModulesFEC and IOM standard panelsVAV Modular AssemblyController Configuration ToolWireless commissioning toolNetwork sensors

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Life Safety & Smoke Control

Smoke Control Engine

TCP/IP

IFC w/ BACnet option

ServerFunctional IntegrationFunctional Integration

Secondary Secondary reportingreporting

Long term Long term event event

storagestorage

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Configuration ProcessBinary Inputs

StatusTrip Alarm

Binary OutputsStart / Stop

Open / Close

Analog InputsTemperature

Pressure

Analog OutputsValve Position

Damper Position

DDCController

Panel

Wiring from equipment control panels,sensors and actuators are connect to

DDC Controllers.DDC Controllers provide local stand-alone

control to maintain environment

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Configuration ProcessBinary Inputs

StatusTrip Alarm


Open / Close


Pressure


Damper Position

DDCController

Panel

Controllers are networkedwith subsystems to NAE.NAE provides supervisorycontrol and management

features.

TEC

ComputerisedSubsystemsChiller PanelFire Alarm

NetworkController

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Configuration Process

Binary InputsStatus

Trip Alarm


Open / Close


Pressure


Damper Position

DDCController

Panel

NAEs and PCsare on a LAN.PCs provideGUI and data

archiving.

TEC

ComputerisedSubsystemsChiller PanelFire Alarm

NetworkController

NetworkController

Documents

Chapter 9 Analog Electronic Controls - ibse.hkibse.hk/cpd/control/ASHRAE_Workshop_Control_WilliamYick...©ASHRAE 1999 9-47 Configuration Process Binary Inputs Status Trip Alarm Binary