APPENDIX E - 23 09 23 Instrumentation and Controls.pdf

FEDERAL AVIATION ADMINISTRATION JULY 27, 2009

TERMINAL FACILITIES STANDARD DESIGNS

INSTRUMENTATION AND CONTROLS FOR HVAC 23 09 23 - 1

SECTION 23 09 23 – INSTRUMENTATION AND CONTROLS FOR HVAC

PART 1 - GENERAL

1.1 REFERENCES

A. The publications listed below form a part of this Specification to the extent referenced. The publications listed below are referenced as the latest edition published as of the date of this document. The publications are referred to within the text by the basic designation only.

B. Air Movement and Control Association International (AMCA)

1. AMCA 500-D Laboratory Methods of Testing Dampers for Rating

C. American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)

1. ASHRAE Guideline 3 Reducing Emission of Halogenated Refrigerants in Refrigeration and Air-Conditioning Equipment and Systems

D. ASME International (ASME)

1. ASME B16.5 Pipe Flanges and Flanged Fittings

2. ASME B31.1 Power Piping

E. ASTM International (ASTM)

1. ASTM A 126 Gray Iron Castings for Valves, Flanges, and Pipe Fittings

F. Institute of Electrical and Electronics Engineers (IEEE)

1. IEEE C62.41 Recommended Practice for Surge Voltages in Low-Voltage AC Power Circuits

2. IEEE C62.45 Surge Testing for Equipment Connected to Low-Voltage (1000v and less)AC Power Circuits

G. Manufacturers Standardization Society (MSS)

1. MSS SP-110 Ball Valves Threaded, Socket-Weding, Solder Joint, Grooved and Flared Ends

2. MSS SP-72 Ball Valves with Flanged or Butt-Welding Ends for General Service

H. National Fire Protection Association (NFPA)

1. NFPA 70 National Electrical Code

2. NFPA 90A Installation of Air Conditioning and Ventilating Systems

I. Sheet Metal and Air Conditioning Contractors National Association (SMACNA)

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1. SMACNA HVAC Duct Const Stds HVAC Duct Construction Standards - Metal and

Flexible

2. SMACNA HVACTAB HVAC Systems - Testing, Adjusting and Balancing

J. Underwriters Laboratories (UL)

1. UL 1449 Transient Voltage Surge Suppressors

2. UL 506 Specialty Transformers

3. UL 916 Energy Management Equipment

1.2 ADDITIONAL REFERENCES

A. TIA/EIA-232 Interface Between Data Terminal Equipment and Data Circuit-Terminating Equipment Employing Serial Binary Data Exchange;

B. TIE/EIA-485 Electrical Characteristics of Generators and Receivers for Use in Balanced Digital Multi-point Systems;

C. TIA/EIA-568 Commercial Building Telecommunications Wiring Standard;

D. FCC 47 CFR Part 15, Subpart B - Unintentional Radiators; and

E. NEMA ICS-6 Enclosures for Industrial Control Systems.

1.3 GENERAL REQUIREMENTS

A. The direct digital control (DDC) shall be a complete system suitable for the heating, ventilating and air conditioning (HVAC) system. The manufacturing facility where the DDC controllers are produced shall be ISO 9001 certified. The control system shall be of open protocol.

1.4 DEFINITIONS

A. Digital Controller: A control module which is microprocessor based, programmable by the user, has integral input/output within the module or on network connected modules, and performs stand-alone operations.

B. Direct Digital Control (DDC): Digital controls, as defined in this Section, performing control logic. The controller directly senses building environment and makes control decisions based on user defined, controller resident programs. The controller outputs control signals that directly operate valves, dampers, and motor controllers. No conventional control devices, pneumatic or electronic, such as receiver-controllers, thermostats, and logic units are present within or interface with a direct digital control loop. Actuators are electric or pneumatic, and the controller output is converted to the appropriate type of signal.

C. DDC System: A system made up of one or more digital controllers which communicate on a network.

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D. Distributed Control: The intent of distributed control is to install the controllers near their respective controlled equipment. The control system consists of stand-alone controllers, with the total number of input and output points limited to 48 or less per controller. Failure of any single controller will not cause the loss of more then 48 control points.

E. Dynamic Control: A process that optimizes energy efficiency of HVAC systems (air handling units, chillers, air-cooled fluid cooler, pumps) and as specified by increasing and decreasing setpoints or starting and stopping equipment in response to heating and cooling needs of the facility. A requirement of dynamic control is knowing the heating/cooling demand status of the process. Therefore dynamic control requires controllers connected in a communications network.

F. Firmware: Firmware is software programmed into read only memory (ROM) and erasable programmable read only memory (EPROM) chips. Software may not be changed without physically altering the chip.

G. Hand-Held Terminal: A hand-held terminal is a manufacturer specific device connected directly to a communications port on a controller, through which the controller is accessed and, in some cases, programmed.

H. Input/Output (I/O) Points: I/O points refer to analog inputs (AI), digital inputs (DI), analog outputs (AO), and digital outputs (DO) in a digital controller. Another term for digital inputs and outputs is binary inputs and outputs. Inputs are from analog sensors (temperature, pressure, humidity, flow) and digital sensors (motor status, flow switches, switch position, and pulse output devices). Outputs operate modulating and on/off control devices.

I. I/O Expansion Unit: An I/O expansion unit provides additional point capacity to a digital controller and communicates with the stand-alone digital controller on a LAN. An I/O unit is not stand-alone because the control program does not reside in the I/O unit. An I/O expander which connects directly to a stand alone controller through a multi-line microprocessor bus is restricted to reside within 3 feet of the stand alone controller and is considered part of the stand alone controller.

J. Local Area Network (LAN)

1. A communications bus that interconnects digital controllers for peer-to-peer (see "peer-to-peer" below) communications. Different levels of LANs are possible within a single DDC system. In this case, a digital controller on a higher level LAN acts as a network controller to the controllers on the lower level LAN. The network controller, then, has at least two LAN communications ports. One port supports peer-to-peer communications with other digital controllers on the higher level LAN. The other port supports communications with the digital controllers on the lower level LAN.

2. LANs permit sharing global information. This allows building and site wide control strategies such as peak demand limiting, dynamic control strategies, coordinated response to alarm conditions, and remote monitoring and programming of digital controllers.

K. Microprocessor: A microprocessor refers to the central processing unit (CPU) that contains all registers and logic circuitry that allow digital controllers to function.

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L. Output Signal Conversion: Output signal conversion refers to changing one kind of control output into a proportionally related signal appropriate for direct actuation of the controlled device. An example is converting a 4 to 20 mA or 0 to 10 VDC signal to a proportional 3 to 15 psig signal to operate a pneumatic actuator.

M. Optimum Start: Optimum start is a method of starting HVAC equipment prior to scheduled occupancy in order to have the building at setpoint when occupied. Optimum start is based on the zone temperatures, zone setpoints, and outdoor temperature.

N. Peer-to-Peer: Peer-to-peer refers to controllers connected on a communications LAN that act independently, as equals, and communicate with each other to pass information.

O. PID: PID refers to proportional, integral, and derivative control; the 3 types of action that are used in controlling modulating equipment.

P. Resolution: Refers to the number of possible states an input value or output value can take and is a function of the digital controller I/O circuitry; the A/D converter for input and the D/A converter for output. Ten bit resolution has 1024 possible states.

Q. Stand-Alone Control: Refers to the digital controller performing required climate control, and energy management functions without connection to another digital controller or computer.

Requirements for stand-alone control are a time clock, a microprocessor, resident control programs, PID control, and I/O. All stand-alone controllers have a communication port and firmware for direct connection and interrogation with a laptop computer or similar hand-held device. This interrogation includes parameter changes and program downloads.

R. Terminal Control Unit (TCU): An off-the-shelf, stand-alone digital controller equipped for communication on a lower level LAN. TCUs may deviate from stand-alone only in receiving energy management and time information from a stand alone digital controller. A TCU is commonly application specific and is used for distributed control of specific HVAC subsystems. A TCU communicates with other digital controllers. Typically, a TCU communicates on a lower level LAN. Examples where TCUs are used include small air-handling units (AHUs), variable air volume (VAV) boxes, fan coil units, and heat pumps.

1.5 DDC SYSTEM DESCRIPTION

A. Provide new DDC systems including associated equipment and accessories. Manufacturer's products, including design, materials, fabrication, assembly, erection, examination, inspection, and testing shall be in accordance with ASME B31.1 and NFPA 70, except as modified herein or indicated otherwise.

B. Provide the DDC systems to maintain stable temperature control and all other conditions as indicated. The end-to-end accuracy of the system, including temperature sensor error, wiring error, A/D conversion, and display, shall be 1 degree F or less.

C. Provide a DDC system with workstation software.

D. Design Requirements

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1. Control System Schematic: Provide control system schematic that includes the following:

a. Location of each input and output device.

b. Flow diagram of each HVAC component, for instance flow through coils, fans, dampers.

c. Name or symbol for each component such as V-1, DM-2, and T-1 for a valve, damper motor, and temperature sensor, respectively.

d. Setpoints.

e. Sensor range.

f. Actuator range.

g. Valve and damper schedules and normal position.

h. Switch points on input switches.

i. Written sequence of operation for each schematic.

j. Schedule identifying each sensor and controlled device with the following infor-mation:

1) LAN and Software point name with send and receive address if applicable

2) Point type (AO, AI, DO, DI)

3) Point range

4) Digital controller number for each point

2. Electrical Equipment Ladder Diagrams: Submit diagrams showing electrical equipment interlocks, including voltages and currents.

3. Component Wiring Diagrams: Submit a wiring diagram for each type of input device and each type of output device. Diagram shall show how the device is wired and powered; showing typical connections at the digital controller and each power supply, as well as at the device itself. Show for all field connected devices, including, but not limited to, control relays, motor starters, electric or electronic actuators, and temperature, pressure, flow, proof, and humidity sensors and transmitters.

4. Terminal Strip Diagrams: Submit a diagram of each terminal strip, including digital controller terminal strips, terminal strip location, termination numbers and associated point names.

5. Communication Architecture Schematic: Submit a schematic showing communication networks used for all DDC system controllers, workstations, and field interface devices.

1.6 SUBMITTALS

A. The following shall be submitted:

1. Design Submittals

a. List of Drawings

b. List of Symbols and Abbreviations Used on Drawings

c. List of I/O Points

d. Equipment Components List

e. AC Power Table

2. Shop Drawings

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a. Control system schematic

b. Ladder diagrams

c. Component wiring diagrams

d. Terminal strip diagrams

e. Communication architecture schematic

3. Product Data

a. DDC hardware

b. DDC capabilities

c. Variable Frequency Motor Drives

d. Workstation software

e. Input devices

f. Output devices

g. Surge and Transient Protection

h. Notebook computer

i. Hand-Held terminal

j. Smoke detectors

4. Test Reports

a. Field Test Plan

b. Performance Verification Test Plan

c. Field Tests

d. Performance Verification Tests

5. Certificates

a. Installers Qualifications

b. Training

6. Operation and Maintenance Data

a. Controls and HVAC System Operators Manual

b. DDC Manufacturer's Hardware and Software Manuals

7. Closeout Submittals

a. Training Course Documentation

b. Service organizations

c. Installer certification

1.7 Operating environment

A. Protect components from humidity and temperature variations, dust, and other contaminants, within limits published by the manufacturer.

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1.8 QUALITY ASSURANCE

A. Standard Products: Material and equipment shall be standard products of manufacturer regularly engaged in the manufacturing of such product, using similar materials, design and workmanship. The standard products shall have been in commercial or industrial use for 2 years prior to bid opening. The 2-year use shall include applications of similarly sized equipment and materials used under similar circumstances and sold on the commercial market through advertisements, manufacturers' catalogs, or brochures. Products are supported by a local service organization.

B. Nameplates and Tags: Nameplates and tags bearing device unique identifiers shall be engraved or stamped. Permanently attach nameplates to HVAC control panel doors and back plates. For each field mounted piece of equipment attach a plastic or metal tag with equipment name and point identifier.

C. Verification of Dimensions: Verify all dimensions in the field, and shall advise the Contracting Officer's Representative (COR) of any discrepancy before performing work.

D. Drawings: Because of the small scale of the drawings, it is not possible to indicate all offsets, fittings, and accessories that may be required. Carefully investigate the mechanical, electrical, and finish conditions that could affect the work, and shall furnish all work necessary to meet such conditions.

1. List of Drawings: Provide a list of drawings.

2. List of Symbols and Abbreviations Used on Drawings: Provide an index of symbols and abbreviations used on the drawings.

3. List of I/O Points: For each input and output physically connected to a digital controller provide, on a controller by controller basis, the following:

a. Point description: for example: mixed air temperature, supply fan start/stop, etc.

b. Point type: AO, AI, DO, or DI.

c. Point range.

d. Sensor range associated with point range:

e. Software name(s) associated with point, if any.

f. Point connection terminal number.

4. Equipment Components List: Submit a listing of controllers and connected devices shown on control system schematic. List the following:

a. Control system schematic name.

b. Description.

c. Manufacturer of controller.

d. Controller's name.

e. Equipment part numbers.

f. Cv for valves.

g. For actuators:

1) Motive force (electric).

2) Normal position.

3) Nominal operating range (4 to 8 mA).

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5. AC Power Table: Submit a table listing each controller and the circuit breaker number, panel box number, and physical location of each controller's source of AC power.

E. Installer’s Qualifications: The Installer performing the work shall have completed at least three DDC systems installations of a similar design and have successfully operated a similar sequence of operation for at least three years.

F. Training Course Documentation: Training course documentation including a manual for each trainee plus two additional copies and one copy of audiovisual training aids, if used.

Documentation shall include an agenda, defined objectives for each lesson and detailed description of the subject matter of each lesson.

G. Service Organizations: Qualified service organization list including the names and telephone numbers of organizations qualified to service the HVAC control systems.

H. Installer Certification: Provide certification that installation of the control system is complete and meets the technical requirements of this section.

I. Controls and HVAC System Operators Manual: Provide two copies of a Control and HVAC Systems Operators Manual. Provide in a 3-ring binder with a minimum of the following seven sections. Use tabs to divide each section.

1. Description of HVAC Systems: Provide a description of the HVAC system components and control system. Include sequence of operation and a complete points list.

2. Controls Drawings: Provide drawings as specified in submittal paragraph.

3. Control Program Listings: Provide listing of all control programs, including terminal equipment controller setup pages if used.

4. Current Operating Parameters: Provide printouts of input and output setup information, (database setups). This section provides information such as point addresses, slopes and offsets for all points, database of points, etc.

5. Design Information: Include relevant design data and calculations.

6. Control Equipment Technical Data Sheets: Provide technical data sheets for all controller hardware and accessories.

7. Backup of Control Program: Provide backup copies of the control program and ACAD control drawings on CD-ROM.

8. DC Manufacturer's Hardware and Software Manuals: Provide the following manuals.

a. Installation and Technical Manuals for all digital controller hardware.

b. Installation and Technical Manuals for workstation.

c. Operator Manuals for all digital controllers.

d. Operator Manuals for all workstation software.

e. Programming Manuals for all digital controllers.

f. Programming Manuals for workstation software.

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PART 2 PRODUCTS

2.1 DDC SYSTEM

A. Provide a DDC system as a distributed control system. The system shall have stand-alone digital controllers, a communications Network, and a separate workstation computer with workstation software.

B. Provide an operator programmable system to perform closed-loop, modulating control of building equipment. Connect all digital controllers through the communication network to share common data and report to workstation computers. Provide workstation DDC software capable of programming and monitoring the digital controllers. The control system shall be capable of downloading programs between the workstation and digital controllers.

C. Direct Digital Controllers: DDC hardware shall be UL 916 rated.

1. Distributed Control: Apply digital controllers in a distributed control manner.

2. I/O Point Limitation: Total number of I/O hardware points, including those communicated over a LAN, used by a single stand-alone digital controller, including I/O expansion units shall not exceed 48.

3. Environmental Operating Limits: Provide digital controllers that operate in environmental conditions between 32 and 120 degrees F.

4. Stand-Alone Control: Provide stand-alone digital controllers.

5. Internal Clock: Provide a clock with each stand-alone controller. Each controller shall have its clock backed up by a battery or capacitor with sufficient capacity to maintain clock operation for a minimum of 72 hours during power outage.

6. Memory:

a. Provide sufficient memory for each controller to support required control, communication, trends, alarms, and messages.

b. Memory Protection: Programs residing in memory shall be protected either by using EEPROM, flash memory, or by an uninterruptible power source (battery or uninterruptible power supply (UPS)). The backup power source shall have sufficient capacity to maintain volatile memory during an AC power failure. Where the uninterruptible power source is rechargeable (a rechargeable battery), provide sufficient back-up capacity for a minimum of seventy-two hours. The rechargeable power source shall be constantly charged while the controller is operating under normal line power. Where a non-rechargeable power source is used, provide sufficient capacity for a minimum of two years accumulated power failure.

Batteries shall be replaceable without soldering.

7. Inputs: Provide input function integral to the direct digital controller. Provide input type(s) as required by the DDC design. For each type of input used on high-level controllers, provide at least one similar spare input point per controller.

a. Analog Inputs: Allowable input types are 100 ohm (or higher) platinum RTDs, thermistors, 4 to 20 mA, and 0-10 VDC. Thermistor and direct RTD inputs must have appropriate conversion curves stored in controller software or firmware. Ana-log to digital (A/D) conversion shall have 10-bit minimum resolution.

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b. Digital Inputs: Digital inputs shall sense open/close, on/off, or other two state indi-cations.

8. Outputs: Provide output function integral to the direct digital controller. Provide output type(s) as required by the DDC design. For each type of output used on high-level controllers, provide at least one similar spare output point per controller.

a. Analog Outputs: Provide controllers with 10 bit minimum output resolution. Out-put shall be 4 to 20 mA, 0 to 10 VDC, or 0 to 20 psig.

b. Digital Outputs: Provide contacts rated at a minimum of 1 ampere at 24 volts.

9. PID Control: Provide controllers with proportional integral, and derivative control capability. Terminal controllers (TCV) are not required to have the derivative component.

10. Digital Controller Networking Capabilities: The upper level digital controllers shall be capable of networking with other similar upper level controllers. Upper level controllers shall also be capable of communicating over a network between buildings.

11. Communications Ports:

a. Controller-to-Controller LAN Communications Ports: Controllers in the building DDC system shall be connected in a communications network. Controllers shall have controller to controller communication ports to both peer controllers (upper level controllers) and terminal controllers (lower level controllers). Network may consist of more than one level of local area network and one level may have multi-ple drops. Communications network shall permit sharing information between controllers, allowing execution of dynamic control strategies, and coordinated re-sponse to alarm conditions. Minimum baud rate for the lowest level LAN is 9600 Baud. Minimum baud rate for the highest level LAN shall be 9600 Baud. Mini-mum baud rate for a DDC system consisting of a single LAN is 9600 Baud.

b. On-Site Interface Ports: Provide a RS-232, RS-485, or RJ-11 communications port for each digital controller that allows direct connection of a computer or hand held terminal and through which the controller may be fully accessed. Controller access shall not be limited to access through another controller. On-site interface commu-nication ports shall be in addition to the communications port(s) supporting con-troller to controller communications. Communication rate is 9600 Baud minimum.

Every controller on the highest level LAN shall have a communications port sup-porting direct connection of a computer; a hand held terminal port is not sufficient.

By connecting a computer to this port, every controller in the direct digital control system shall be accessible and programmable. The following operations shall be available: downloading and uploading control programs, modifying programs and program data base, and retrieving or accepting trend reports, status reports, mes-sages, and alarms.

c. Remote Work Station Interface Port: Provide one additional direct connect com-puter port in each DDC system for permanent connection of a remote operator's work station, unless the workstation is a node on the LAN. All operations possible by directly connecting a computer to a controller at the highest level LAN shall be available through this port.

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12. Modem: Provide two modems per DDC system to communicate between the digital control system and the computer workstation. Minimum modem baud rate is 56 Kbaud with v.90 communication standard.

13. Digital Controller Cabinet: Each indoor digital controller cabinet shall protect the controller from dust and be rated NEMA 1, unless specified otherwise. Each outdoor digital controller cabinet shall protect the controller from all outside conditions and be rated NEMA 4. Cabinets for high level controllers shall be hinged door, lockable, and have offset removable metal back plate.

14. Main Power Switch: Each controller on the highest level LAN or each control cabinet shall have a main external power switch for isolation of the controller from AC power.

The switch shall be located in the DDC cabinet.

D. Terminal Control Units (TCUs)

1. The same company as the digital controllers shall manufacture TCUs.

2. TCUs shall automatically start-up on return of power after a failure, and previous operating parameters shall exist or shall be automatically downloaded from a digital controller on a higher level LAN.

3. TCUs do not require an internal clock if they get time information from a higher level digital controller.

E. DDC Software

1. Sequence of Control: Provide, in the digital controllers, software to execute the sequence of control. Provide one registered copy of all software used to program control sequences in all direct digital controllers and LAN controllers on the computer workstation. Provide any access keys which restrict programming language software functions or the ability to compile or prepare programming for download to controllers. Provide final copy of each program used in the system in both compiled and editable formats. Where specially programmed factory configured smart controllers are used in the system, provide minimum factory programming tools and specialized controller programs ready for download to replacement controllers. At minimum, controllers must be capable of performing programming functions outlined in the following "Parameter Modification" article.

2. Parameter Modification: Provide software to modify control parameters. Parameter modification for all controllers (high level and low level application specific) is through the main workstation computer and with laptop computer or keypad terminal directly at each controller. Modifications accomplished without having to make changes directly in line-by-line programming. When the control program is of the line-by-line type, database parameters in the following list that take real number values require assignment of variable names so parameters can be changed without modifying programming.

Alternatively, block programming languages shall provide for modification of these database parameters in fill-in-the-blank screens. Parameters of like type, including those in different high level and low level controllers, may be grouped together for a single, global change. For example, an operator may group all second floor space temperature setpoints into a group and raise the setpoint by two degrees with a single command. The following parameters shall be modifiable in this way:

a. Setpoints

b. Dead band limits and spans

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c. Reset schedules

d. Switch over points

e. PID gains and time between control output changes

f. Time

g. Timed local override time

h. Occupancy schedules

i. Holidays

j. Alarm points, alarm limits, and alarm messages

k. Point definition database

l. Point enable, disable, and override

m. Trend points, trend intervals, trend reports

n. Analog input default values

o. Passwords

p. Communications parameters including network and telephone communications setups

3. Differential: Where setpoint is in response to some analog input such as temperature, pressure, or humidity, include a setpoint differential to prevent short cycling of control devices.

4. Motor and Flow Status Delay: Provide an adjustable delay between when a motor is commanded on or off and when the control program looks to the motor or flow status input for confirmation of successful command execution.

5. Run time Accumulation: Provide resettable run time accumulation for each controlled digital output.

6. Timed Local Override: Provide user definable adjustable run time for each push of a momentary contact timed local override. Pushes shall be cumulative with each push designating the same length of time. Provide a user definable limit on the number of contact closures summed, such as 6, before the contact closures are ignored. Timed local overrides are disabled during occupancy periods.

7. Time Programs: Provide programs to automatically adjust for leap years, daylight savings time, and operator time adjustments.

8. Scheduling

a. Individual controlled equipment shall be programmable with schedule based on time of day, day of week, and day of year. Equipment may be associated into groups. Each group may be associated with a different schedule. Changing the schedule of a group shall change the schedule of all equipment in the group.

Groups may be modified, created and deleted by the operator.

b. Provide capability to view and modify schedules in a seven-day week format.

When control program does not automatically compute holidays, provide capability to enter holiday schedules one full year at a time.

9. Point Override: I/O and virtual points shall accept software overrides to any possible value.

10. Alarming: I/O points, software points, and all devices with feedback shall be alarmable.

The type of alarm shall be determined by the Resident Engineer (routine, priority, critical, etc.). Alarms may be enabled and disabled for every point. Alarm limits shall be adjustable on analog points. Controllers connected to an external communications device such as a printer, terminal, or computer, shall download alarm and alarm message when alarm occurs. When a computer workstation is connected to a DDC system with a LAN

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or modem, operator selected alarm conditions will initiate a call and report to the computer. Otherwise alarms will be stored and automatically downloaded when a communications link occurs. The following conditions shall generate alarms:

a. Motor is commanded on or off but motor status input indicates no change

b. Temperature, humidity, or pressure strays outside selectable limits

c. An analog input takes a value indicating sensor failure

d. A module is not communicating on the LAN

e. A power outage occurs

f. Damper or valve is commanded open or closed, but limit switch status does not change.

11. Messages: Messages shall be operator defined and assigned to alarm or status conditions.

Messages shall be displayed on the workstation or printer when these conditions occur.

12. Trending: DDC system shall have the capability to trend all I/O and virtual points.

Points may be associated into groups. A trend report may be set up for each group. The period between logging consecutive trend values shall range from 1 minute to 60 minutes at a minimum. The minimum number of consecutive trend values stored at one time shall be 30 per variable. When trend memory is full, the most recent data shall overwrite the oldest data. Trend data shall be capable of being uploaded to a computer. Trend data shall be available on a real time basis; trend data shall appear numerically and graphically on a connected computer's screen as the data is processed from the DDC system. Trend reports shall be capable of uploading a to computer for storage.

13. Status Display: Current status of I/O and virtual points shall be displayed on command.

Points shall be associated into functional groups, such as all the I/O and virtual points associated with control of a single air-handling unit, and displayed as a group, so the status of a single mechanical system can be readily checked. A group shall be selectable from a menu of groups having meaningful names; such as AHU-4, Second Floor, Chiller System, and other such names.

14. Diagnostics: Each controller shall perform self-diagnostic routines and provide messages to an operator when errors are detected. The DDC system shall be capable of recognizing a non-responsive module on a LAN. The remaining, responsive modules on a LAN shall not operate in a degraded mode.

15. Power Loss: During a power outage, each controller shall assume a disabled status and outputs shall go to a user definable state. Upon restoration of power, DDC system shall perform an orderly restart, with sequencing of outputs.

16. Program Transfer: Provide software for download of control programs and database from a computer to controllers and upload of same to computer from controllers. Every digital controller in the DDC system shall be capable of being downloaded and uploaded to through a single controller on the highest level LAN.

17. Password Protection: Provide at least three levels of password protection to the DDC system permitting different levels of access to the system. The lowest level allows monitoring only. The highest level allows full control of all functions, including setting new passwords.

F. Workstation: Provide a central workstation computer with installed software to provide an interface for monitoring, troubleshooting, and making adjustments to the program or operating parameters of all DDC controllers, including TCUs. The workstation shall also be capable of programming all controllers, including TCUs. DDC system shall routinely operate continuously without connection to the workstation. Information at the workstation is not required for day to day operations of the direct digital controllers.

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1. Hardware: The DDC system manufacturer shall recommend all workstation computer equipment and peripherals. The workstation shall be configured to operate according to the DDC system manufacturer's specifications. Workstation hardware shall be configured to allow operation of software, uploading and downloading of programs, and creation of graphics. At a minimum the workstation hardware shall consist of:

a. Computer; computer shall use Microsoft Windows 10, and shall not have less than

Intel Core i5 processor running at 3.2 gigahertz speed, 250 giga-byte hard disc, 8 giga-byte RAM, 1 serial and 1 parallel port, 2 USB ports, 17-inch monitor with 1280 x 768 minimum resolution, 101 character keyboard, 48X internal CD ROM drive.

b. Mouse

c. Modem; 56 Kbaud, v.90 standard

d. Printer; printer shall be laser output with one spare cartridge.

e. 120-volt terminal strip UL 1449 6-outlet with surge protection.

2. Software: Workstation software shall be configured to operate according to the DDC system manufacturer's specifications. Software shall be installed in the workstation computer and permit monitoring and troubleshooting of the DDC system. Workstation software permits modification of controller parameters and control for all controllers, both high level and low level application specific. Operations shall be menu selected.

Menu selections shall be made with a mouse.

a. Menu System: Menu system shall allow an operator to select a particular function or access a particular screen through successive menu penetration.

b. Controller Parameter Modification: The workstation software shall be an interface for performance specified in paragraph entitled "Parameter Modification" and available through direct connection of a computer to a digital controller. Parameter modification shall require only that an operator "fill in the blank" for a parameter on a screen requesting the information in plain language. Parameter modifications shall download to the appropriate controllers at operator request.

c. Program modification: For systems using a line-by-line programming language, provide an off-line text editor, similar to a BASIC program editor, permitting mod-ification of controller resident control programs. For systems using block pro-gramming languages provide a capability for linking blocks together to create new programs or modify existing programs. Program modifications shall download to appropriate controllers at operator request.

3. Dynamic Graphic Programming: Construct the "dynamic" graphics pages for monitoring and system control. This graphics utility shall be usable both for on-line control such as override and alarm acknowledgement, and for display of system status and alarm activity.

Graphics shall support at least 16 colors and not less than 60 outputs of real time, live dynamic data per graphic. The system shall display dynamic graphic data as an animated symbol (i.e., when a damper opens, the damper on a graphic plan moves to the open position; fan status "on" shall display fan moving), and ASCII set (i.e., on-off), a decimal )i.e., 96.3F), or as an analog bar graph. Each operator workstation shall support not less than 1,000 separate graphic pages. Include three-dimensional developed graphics for each device as approved by the FAA's representative for this project. The following graphic pages shall be provided:

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a. Graphics shall closely follow the style of the control drawings in representing me-chanical systems, sensors, controlled devices, and point names.

b. Graphic Title: Graphics shall have an identifying title visible when the graphic is being viewed.

c. Dynamic Update: When the workstation is on-line with the control system, point data shall update dynamically on the graphic images.

d. Graphic Penetration: Provide graphic penetration when the capability exists. For systems without graphic penetration, provide menu penetration for selection of in-dividual graphics to give the same hierarchical affect provided by graphic penetra-tion.

e. Graphic Types: Graphic-based software shall have graphics of the building sec-tion, floor plans, and mechanical systems. Provide the following graphics:

1) Building Section Graphic: Show stacked floors in section graphic with appropriate floor name on each floor.

2) Floor Plan Graphics: Provide a single graphic for each floor, unless the graphic will contain more information than can reasonably be shown on a single graphic. Each heating or cooling zone within a floor plan shall have a zone name and its current temperature displayed within the zone outline.

The ductwork and associated devices (VAVs, etc.) shall be shown for quick reference of the system layout. Show each controlled variable in the zone.

Provide visual warning for each point in alarm.

3) Mechanical System Graphics: Provide three-dimensional drawings to symbolize mechanical equipment; do not use line drawings. Show controlled or sensed mechanical equipment. Each graphic shall consist of a single mechanical system; examples are a graphic for an air handling unit, a graphic for a VAV terminal unit, a graphic for a split system heat pump unit, a computer room air conditioning unti, CHW loop HW loop, etc. These systems may be combined with prior approval. Place sensors and controlled devices associated with mechanical equipment in their appropriate locations.

Place point name and point value adjacent to sensor or controlled device.

Provide visual indication of each point in alarm. Conditions, such as zone temperature, associated with the mechanical system shall be shown on the graphic. Point values shall update dynamically on the graphic.

f. Graphic Editing: Full capacity as provided by a draw software package shall be in-cluded for operator editing of graphics. Graphics may be created, deleted, modi-fied, and text added. Provide capability to store graphic symbols in a symbol direc-tory and incorporate these symbols into graphics. A minimum of 16 colors shall be available.

g. Dynamic Point Editing: Provide full editing capability for deleting, adding, and modifying dynamic points on graphics.

h. Trending: Trend data shall be displayed graphically, with control variable and pro-cess variable plotted as functions of time on the same chart. Graphic display of trend data shall be a capability internal to the workstation software and not a capa-bility resulting from download of trend data into a third-party spreadsheet program such as Excel, unless such transfer is automatic and transparent to the operator, and

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the third-party software is included with the workstation software package. At the operator's discretion, trend data shall be plotted real time.

4. Display Graphics of the HVAC System and HVAC Status: A visual interface for the operator shall be provided and displayed on the monitor screen. The system shall support an operator definable "default" system page. The default system page shall be displayed upon system startup, operator activity time-outs, and when the system is not in use. This default system page may be any one of the standard dynamic graphic pages, or may be a custom display developed for this purpose. The graphics shall as a minimum be representative of the floor plans of the buildings, including, each room with identification; representative of the HVAC equipment and each individual component location on the floor plans; elevation views which represent the vertical relationships of the HVAC equipment located in the Tower; and indication of the operational status of each HVAC component. The graphic pages shall provide direct access to all DDC controlled points. The user shall be provided access to all controllable aspects of every component of the HVAC system directly from the graphics pages; including checking device status to manually controlling each component of every device. This includes, but is not limited to, the requirements as indicated on the point system lists and the flow diagrams on the drawings.

5. Dynamic Graphic Flow Chart Programming: Construct "dynamic" graphic flow charts of system control logic/sequences for each sequence. This flow chart utility shall be usable both for on-line control logic development (i.e., programming), and for live displays of the interactive process variables occurring throughout the sequences of operations. Flow chart elements shall consist of "icons" selected from a "toolkit". The cursor and mouse shall be used to place the icons on the graphic, and to connect the icons, or modules.

Text may be inserted into the graphic to describe the control logic in sentence format.

Once completed, the graphics shall be able to be printed out for permanent records.

G. Maintenance Personnel Interface Tools: Provide a notebook computer for field communication with the digital controllers. In addition to changing setpoints, and making operational changes, field personnel shall be able to download programs with the notebook computer.

1. Notebook Computer

a. Provide notebook computer, necessary software, carrying case, and direct connec-tion cable to communicate with all digital controllers when directly connected.

b. Provide notebook computer with the following features as a minimum:

1) Intel Core i5 processor, 3.2 gigahertz speed,

2) Internal hard disk; minimum 250 giga bytes

3) Internal battery operation; for a minimum of 5 hours of operation.

4) RAM; minimum 8 gigabytes

5) 48X CD RW

6) Serial interface port to communicate with the digital controller. Parallel port to communicate with a printer. Two high-speed USB ports.

7) Software: Digital control manufacturer's graphic DDC software, and all other required programs installed. Windows XP operating system installed.

Include all documentation and original media.

2.2 SENSORS AND INPUT HARDWARE

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A. Field Installed Temperature Sensors

1. Thermistors: Precision thermistors may be used in temperature sensing applications below 200 degrees F. Sensor accuracy over the application range shall be 0.36 degree F or less between the range of 32 to 150 degrees F. Stability error of the thermistor over 5 years shall not exceed 0.25 degree F cumulative. Sensor element and leads shall be encapsulated. Bead thermistors are not allowed. A/D conversion resolution error shall be kept to 0.1 degree F. Total error for a thermistor circuit shall not exceed 0.5 degree F, which includes sensor error and digital controller A/D conversion resolution error.

Provide 18 gage twisted and shielded cable for thermistors.

2. Resistance Temperature Detectors (RTDs): Provide RTD sensors with 1000 ohm, or higher, platinum elements that are compatible with the digital controllers. Sensors shall be encapsulated in epoxy, series 300 stainless steel, anodized aluminum, or copper.

Temperature sensor accuracy shall be 0.1 percent (1 ohm) of expected ohms (1000 ohms) at 32 degrees F. Temperature sensor stability error over 5 years shall not exceed 0.25 degree F cumulative. Direct connection of RTDs to digital controllers, without transmitters, is preferred provided controller supports direct connection of RTDs. When RTDs are connected directly to the controller, keep lead resistance error to 0.25 degree F or less. Total error for a RTD circuit shall not exceed 0.5 degree F, which includes sensor error, lead resistance error or 4 to 20 mA or 0 to 10 VDC transmitter error, and A/D conversion resolution error.

3. Temperature Sensor Details:

a. Room Type: Conceal element behind protective cover matched to the room interi-

or. Room temperature sensors connected directly to application specific controllers shall have integral pushbutton, system override digital input button, and a setpoint adjustment lever. Provide a connection to allow interrogation of the digital control-ler.

b. Duct Averaging Type: Continuous averaging RTDs for ductwork applications shall be one foot in length for each 4 square feet of ductwork cross-sectional area with a minimum length of 6 feet. Probe type duct sensors of 1-foot length mini-mum are acceptable in ducts 12 feet square and less.

c. Immersion Type: Three inches total immersion for use with sensor wells, unless otherwise indicated.

d. Sensor Wells: Stainless steel material. Provide heat-sensitive transfer agent be-tween exterior sensor surface and interior well surface.

e. Outside Air Type: Provide element on the buildings north side with sunshade to minimize solar effects. Mount element at least 3 inches from building outside wall.

Sunshade shall not inhibit the flow of ambient air across the sensing element.

Shade shall protect sensing element from snow, ice, and rain.

B. Transmitters: Transmitters shall have 4 to 20 mA or 0 to 10 VDC output linearly scaled to the temperature, pressure, humidity, or flow range sensed. Transmitter shall be matched to the sensor, factory calibrated, and sealed. Total error shall not exceed 0.1 percent at any point across the measured span. Supply voltage shall be 24 volts AC or DC. Transmitters shall have non-interactive offset and span adjustments. For temperature sensing, transmitter stability shall not exceed 0.05 degrees C a year.

1. Spans and Ranges: Transmitter spans or ranges shall meet the following:

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a. Temperature:

1) 50 degrees F span: Room, chilled water, cooling coil discharge air, return air sensors.

2) 100 degrees F span: Outside air, mixed air sensors.

b. Pressure:

1) Negative 0.5 to positive 0.5 inches water differential range: static pressure control of rooms.

2) 0 to 5 inches water differential range: Duct static pressure.

3) 0 to 60 pounds per square inch gage differential: Water differential pressure.

c. Relative Humidity:

1) 10 to 90 percent minimum relative humidity range.

2. Relative Humidity Transmitters: Provide integral humidity transducer and transmitter.

Output of relative humidity instrument shall be a 4 to 20 mA or 0 to 10 VDC signal proportional to full range of relative humidity input. Accuracy shall be 2 percent of full scale, long-term stability shall be less than 1 percent drift per year. Sensing element shall be polymer type.

3. Pressure Transmitters: Provide integral pressure transducer and transmitter. Output of pressure instrument shall be a 4 to 20 mA signal proportional to the pressure span.

Accuracy shall be 1.0 percent. Linearity shall be 0.1 percent.

4. Current Transducers: Provide current transducers to monitor amperage of motors. Select current transducer for normal measured amperage to be near 50 percent of full-scale range. Current transducers shall have an accuracy of 1 percent and 4 to 20 mA or 0 to 10 VDC output signal.

5. Air Quality Sensors:

a. CO2 Sensor: Provide CO2 sensors with integral transducers where shown. Output signal shall be 4 to 20 mA or 0 to 10 VDC. Accuracy shall be plus or minus 5 percent of full scale.

6. Input Switches

a. Timed Local Override: Provide momentary contact push button override with override time set in controller software. Provide to override DDC time of day program and activate occupancy program for assigned units. Upon expiration of override time, the control system shall return to time-of-day program. Time interval for the length of operation shall be software adjustable and shall expire unless reset.

b. Hand-Off-Auto Switch: Provide hand-off-auto switch with name plate to manually switch between off, DDC (auto) and manual (hand) control. Size and wire hand-off-auto switch to switch control (120 VAC or less), not line, circuitry. Wire all safety controls to protect circuit and equipment during both hand and auto operation.

c. Insertion Freeze Protection Switch: Electric switch shall be capillary type.

Provide special purpose insertion thermostats with flexible elements a minimum of

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20 feet in length for coil face areas up to 40 square feet. Switch contacts shall be rated for motor starter circuit voltage being interrupted.