Section 15970 INSTRUMENTATION AND CONTROL FOR HVAC SYSTEMS

Section 15970

INSTRUMENTATION AND CONTROL FOR HVAC SYSTEMS

PART 1 - GENERAL

1.1 SUMMARY

A. Section Includes:

1. Instrumentation and control for HVAC systems.

2. Temperature control.

3. Ventilation control.

4. Heating control.

5. Cooling control.

6. Control wiring.

7. Panels and accessories.

8. Miscellaneous.

B. Related Specification Sections include but are not necessarily limited to:

1. Division 1, Additional General Requirements

2. Section 10400, Identifying Devices

3. Section 11005, Equipment: Basic Requirements

4. Section 15605, HVAC: Equipment

5. Section 15890, HVAC: Ductwork

6. Section 16010, Electrical General Provisions

7. Section 16050, Basic Materials and Methods

8. Section 16075, Electrical Identification Nameplates and Warning Signs

9. Section 16120, Conductors and Cables

10. Section 16130, Raceway Systems and Pull Boxes

11. Section 16442, Control Panels

12. Section 17405, Process Instrumentation and Control

1.2 QUALITY ASSURANCE

A. See Specification Section 11005, Equipment: Basic Requirements. B. Referenced Standards:

1. ASTM International (ASTM):

D1693 Standard Test Method for Environmental Stress- Cracking of Ethylene Plastics

2. Instrumentation, Systems, and Automation Society (ISA):

S5.1 Instrumentation Symbols and Identification

S5.4 Standard Instrument Loop Diagrams

3. National Electrical Manufacturers Association (NEMA):

250 Enclosures for Electrical Equipment (1000 Volts

Maximum)

4. National Fire Protection Association (NFPA):

70 National Electrical Code (NEC)

5. Underwriters Laboratories, Inc. (UL) C. Miscellaneous:

1. Controls to be in compliance with Specification Section 16010, Electrical and General Provisions, for NEMA and NEC enclosure class requirements unless noted or specified otherwise.

2. Unless specifically noted otherwise, components of systems shall be industrial duty suitable for moist, corrosive environments.

1.3 SYSTEM DESCRIPTION

A. Work shall be provided as an integrated operating system.

B. Provide a complete system of automatic temperature control, thermostats, relays, valves, damper operators and other associated controls and appurtenances required to maintain minimum conditions described in detail herein and on Drawings, together with thermometers, gauges and other accessory equipment.

1. Assemble control system with complete system of wiring and conduit to fulfill requirements of the Contract Documents. Contractor to determine conduit routes and cable quantities for all devices wired to the HVAC Main Control Panel 15LFCP950. Wiring and conduit shall meet the requirements of Division 16, Electrical.

C. Install system using competent mechanics under direct supervision of control manufacturer.

D. Controls, as set out in "Sequence of Operation," are designed to illustrate operating functions only.

1. Control sequence shall be considered supplementary to "Sequence of

Operation."

2. These minimum specified items, and any additional controls, not indicated but required to meet performance as outlined in the Contract Documents, shall be furnished and installed at no additional cost to OCSD to make a complete system.

E. Sequence of Operation - General:

1. Sequence of operation indicated illustrates basic operating functions only.

2. CONTRACTOR shall review P&IDs and Drawings and submit complete installation data, including minor details, to provide proper operation in its proposal.

3. Where an item differs from Specifications, control manufacturer shall submit manufacturer's recommendations subject to ENGINEER's approval.

F. Sequence of Operation for the following equipment (Dewatering Building Occupied

Areas Air Handler):

1. Equipment: 15LAHU976, 15LFV972, 15LFCP950, 15LFV669:

a. Air handling unit is started and stopped by a programmable 7-day, 24-hour time clock located in the Dewatering Building HVAC main control panel

15LFCP950. Smoke detector ASH-982 and freezestat shall shut down the unit on smoke detection or on supply air temperature leaving the unit at less than 40 degrees F and signal alarms at 15LFCP950. An alarm signal from ASH-982 shall also be provided to the building fire alarm panel. A temperature controller located in HVAC main control panel 15LFCP950shall modulate the temperature control valve FV-972 to maintain supply air discharge temperature, measured by TIT-

981, at 55 degrees F. Utilizing a selector relay, the supply air temperature is reset from the zone with the greatest cooling demand by the individual zone temperature sensors. Modulate outside air and return air dampers according to the reset schedule indicated on the Drawings for economizer control. Move outside air damper to the minimum position when the outside air rises above 76 degrees F (adjustable). Individual zone control is by four (4) zone temperature sensors which control the variable volume terminal units and electric heating coils. Upon decreasing room temperature modulate damper to the minimum position. On further decrease in room temperature switch the heat coil to the “on” position. The AHU supply fan air flow is controlled by a static pressure sensor in the supply air ductwork which modulates a bypass damper 15LFV669 between the supply and return ductwork. Configure controls so that on a call for cooling by any of the five temperature transmitters, the chiller will cycle for maintaining zone temperatures.

2. Equipment: 15LCHR971:

a. Chiller 15LCHR971 has internal manufacturer provided controls, and is controlled by a local control panel independently from the HVAC control panel. Chiller controls located within the chiller unit will unload and cycle the compressors based on return chilled water temperature. Chiller is provided with a packaged hydronic system for pumping chilled water to the air handling unit. When the outside air is above 55 degrees F enable the chiller and start the hydronic system.

3. Equipment: 15LAC668 and 15LAHU667:

a. The server room is provided with a backup split conditioning system.

15LAC668 and 15LAHU667 shall be controlled by a dedicated 7-day, 24-hour programmable thermostat located in HVAC main control panel 15LFCP950. On call for cooling, the unit fan shall run continuously and the refrigerant system shall cycle to maintain the room at 78 degrees F.

G. Sequence of Operation for the following equipment (Dewatering Building Occupied

Areas Exhaust Fans):

1. Equipment: 15LFAN987, 15LFAN988, 15LFAN989, 15LFAN973, and

15LFCP950:

a. 15LFAN987 shall be interlocked with 15LAHU971 through HVAC main control panel 15LFCP950. When 15LAHU971 runs, this fan is energized to run.

b. 15LFAN988 and 15LFAN989 shall be energized from the room light switch. Fans shall shutdown when the lights are off or after a 30 minute adjustable time delay.

c. 15LFAN973 shall be energized with a switch from the fume hood.

H. Sequence of Operation for the following equipment (Dewatering Building Electrical

Rooms):

1. Equipment: 15LAC951, 15LAC955, FV-952, FV-954, FV-956, FV-958 and

15LFCP950:

a. 15LAC951 and 15LAC955 shall each be controlled by dedicated 7-day, 24- hour programmable thermostats TSHL-959 and TSHL-961 located in the respective Electrical Room. Modulate outside air and return air dampers (internal to units) according to the following reset schedule for economizer control. Move outside air damper to the minimum position when the outside air rises above 76 degrees F (adjustable). The units shall cycle to maintain the rooms at 90 degrees F. Duct smoke detectors ASH-953 and ASH-957 shall shut down their respective AC unit on smoke detection and signal an alarm at the Dewatering Building HVAC main control panel 15LFCP950. Alarm signals from ASH-953 and ASH-957 shall also be provided to the building fire alarm panel. High room temperature sensors/transmitters TE/TIT-960 and TE/TIT-962 in each respective Electrical Room shall provide temperature indication to plant PLC. Low flow switches FSL-963 and FSL-964 on supply duct of each unit shall signal an alarm at 15LFCP950 on detection of low flow. Electrical and Switchgear Rooms ventilation fans must always be “on”. Thermostats shall control only the temperature, and not the fans. These rooms must have positive pressure with respect to ground level.

b. Motorized control damper FV-952, and FV-956 shall be normally open. FV-

954 and FV-958 shall be provided with a switch in the HVAC main control panel to remotely open and close the dampers if one AC unit is out of service. Dampers shall be provided with position switches and provide open/close signals to

15LFCP950. If FV-952 or FV-956 is closed, the respective air conditioning unit

shall not start and an alarm shall be signaled at 15LFCP950. FV-956 shall also be interlocked with the fire alarm system. On a signal from the fire alarm system, damper shall close and 15LAC955 shall shut down and signal an alarm at15LFCP950.

c. Reset Schedule:

Mixed Air Temp, Degrees F	Return Air Temp, Degrees F
55	76
60	74
65	72

I. Sequence of Operation for the following equipment (Dewatering Building Centrifuge

Room, Basement, and Tunnel 32):

1. Equipment: 15LAHU965, 15LAHU968, and 15LFCP950:

a. 15LAHU965 and 15LAHU968 supply and exhaust fans shall run continuously. Duct smoke detectors ASH-966 and ASH-969 on the supply duct from each unit shall shut down the respective unit on smoke detection and signal alarms at the Dewatering Building HVAC main control panel 15LFCP950. Alarm signals from ASH-966 and ASH-969 shall also be provided to the building fire alarm panel. Flow sensors FSL-967 and FSL-970 on the supply duct of each unit shall signal an alarm at 15LFCP950 on detection of low flow (66,640 cfm and

57,890 cfm respectively). Each air handling unit is supplied with a set of 3 duty and 1 standby for each set of supply and return/exhaust fans. If a duty fan fails, the standby fan shall automatically be energized and a fail alarm for the failed fan shall be signaled at 15LCP950. Provide selector switches (4 each) at 15LCP950 to select the standby fan at each set of supply and return/exhaust fans at each air handling unit.

b. Tunnel exhaust fan 15LFAN994 shall run continuously. Low flow sensor

FSL-995 on the exhaust duct upstream of the fan shall signal an alarm at

15LFCP950 on detection of low flow (465 cfm).

J. Sequence of Operation for the following equipment (Dewatering Building Battery

Room):

1. Equipment: 15LAC657, 15LFAN652, 15LFAN655, 15LAHU653, and

15LFCP950:

a. 15LAC657 and 15LAHU653 shall be controlled by a dedicated 7-day, 24- hour programmable thermostat located in HVAC main control panel 15LFCP950. On call for cooling, the unit fan shall run continuously and the refrigerant system shall cycle to maintain the room at 78 degrees F.

b. 15LFAN652 shall be interlocked with 15LFAN655. Both fans run continuously. Low flow sensor FSL-665 on supply air duct and low flow sensor FSL-656 on exhaust duct shall signal an alarm at the HVAC main control panel

15LFCP950 on low flow detection (100 cfm).

K. Sequence of Operation for the following equipment (Dewatering Building Elevator

Machine Room):

1. Equipment: 15LAC660 and 15LAHU650:

a. 15LAC660 and 15LAHU650 shall be controlled by a dedicated 7-day, 24- hour programmable thermostat located in HVAC main control panel 15LFCP950. On call for cooling, the unit fan shall run continuously and the refrigerant system shall cycle to maintain the room at 78 degrees F.

L. Sequence of Operation for the following equipment (Tunnel 29):

1. Equipment: 15LFAN974:

a. 15LFAN974 shall run continuously. Low flow sensor FSL-975 mounted on the duct upstream of the fan shall signal an alarm at plant PLC on low flow detection (1,430 cfm).

M. Sequence of Operation for the following equipment (Valve Vault):

1. Equipment: 15LFAN016:

a. 15LFAN016 shall run continuously. Low flow sensor FSL-012 mounted on the duct upstream of the fan shall signal an alarm at the plant PLC on low flow detection (1,900 cfm).

N. Sequence of Operation for the following equipment (Loadout Facility):

1. Equipment: 15JFAN951, FV-957, and 15JFCP959:

a. 15JFAN951 shall run continuously. Duct smoke detector ASH-953 shall shut down the unit on smoke detection and signal an alarm at the HVAC control panel

15JFCP959. An alarm signal from ASH-953 shall also be provided to the building fire alarm panel. Low flow sensor FSL-952 on the discharge of the unit shall

signal an alarm at 15JFCP959 on detection of low flow (11,000 cfm). 15JFAN951 shall be interlocked with FV-957 and shut down if FV-957 is closed.

O. Sequence of Operation for the following equipment (Loadout Facility):

1. Equipment: 15JFAN954, FV-957, and 15JFCP959:

a. 15JFAN954 shall run continuously. Low flow sensor FSL-955 on the discharge of the unit shall signal an alarm at HVAC control panel 15JFCP959 on detection of low flow.

b. FV-957 shall be provided with a switch at 15JFCP959 to remotely open and close the damper. Damper shall be provided with position switches and provide an “open” or “closed” signal to 15JFCP959.

P. Sequence of Operation for the following equipment (Loadout Facility):

1. Equipment: 15JFAN532, 15JFAN533, 15JFAN539, 15JFAN540, and

15JFCP961:

a. Existing two-speed fans shall run continuously and are energized from the MCC panel. Local “fast” and “slow” jog switches shall be located at the existing fans and at the main HVAC Control Panel 15JFCP961.

Q. Sequence of Operation for the following equipment (Loadout Facility):

1. Equipment: 15JFAN000, 15JFAN521, and 15JFAN546:

a. Existing fan 15JFAN000 shall be energized by new local light switch.

b. Existing fans 15JFAN521 and 15JFAN546 shall be energized by new local switches.

R. Sequence of Operation for the following equipment (Loadout Facility):

1. Equipment: 15JAC525:

a. Existing heat pump 15JAC525 shall be controlled by a new programmable

24-hour, 7-day thermostat TS-525 located in the electrical room.

1.4 SUBMITTALS

A. Shop Drawings:

1. Submittals shall be made in accordance with the General Requirements, Additional General Requirements and as specified herein.

2. Plan drawings showing conduit routing, cable schedule and wiring diagrams showing point to point termination with auxiliary interlocks for each item in each control loop.

3. Information on equipment proposed for use including corrosion protection.

4. Instrument loop diagrams and word description of loop function for each individual unit controlled including auxiliary interlocks in full compliance with ISA S5.4.

a. Show components in system and ensure diagrams are in full compliance with ISA S5.1 (Instrumentation Symbols and Identification) and other related ISA standards.

B. Quality Control Submittals:

1. Secure from equipment manufacturers, detailed and complete control and power wiring diagrams, word descriptions of controls provided as part of the HVAC equipment or equipment interfaced or interlocked thereto, and submit with equipment manufacturer's submittals.

a. Provide the above information to control manufacturer. C. Operation and Maintenance Manuals:

1. See Specification Section 01783, Vendor Equipment Manuals, for requirements for:

a. The mechanics and administration of the submittal process b. The content of Operation and Maintenance Manuals

1.5 PROJECT CONDITIONS

A. Unless stated otherwise, the environment and air streams will include varying concentrations of the following chemical components:

1. HSO4 - Sulfuric acid.

2. NH(3) - Ammonia.

3. Cl(2) - Chlorine.

4. H(2)S - Hydrogen sulfide.

5. HCl - Hydrochloric acid.

6. Condensation.

PART 2 - PRODUCTS

2.1 ACCEPTABLE MANUFACTURERS

A. Subject to compliance with the Contract Documents, the following manufacturers are acceptable:

1. Manufacturer's catalog numbers hereinafter are for reference to type, style, dimension, related items and to establish a standard of quality.

a. Reference to a manufacturer's number hereinafter does not imply full compliance to these Specifications.

2. Instrumentation and control systems:

a. Honeywell

b. Johnson Control Co. c. Or Equal.

2.2 EQUIPMENT A. Dampers:

1. Refer to Specification Section 15890, HVAC: Ductwork. B. Damper Operators:

1. Provide operators of proper size and number to secure true throttling or two- position action as required.

2. Furnish damper operators for installation inside ductwork and attached to frame of damper, or installed outside ductwork and connected to extended shaft as required.

3. Provide operators for outside air, spring-loaded with sufficient power to assure tight closing of dampers on fan shutdown or in the fail safe position indicated by "Sequence of Controls."

4. Electric operators:

a. Provide operators:

1) Fully immersed in oil gear train.

2) Enclosed in closed cast aluminum housing. b. Provide operators in NEMA 4X enclosure.

c. Provide damper operators with integral spring return motor springs to make controls fail safe in position specified under "Sequence of Controls."

d. Provide fully modulating operators from proportional electric controllers.

e. Provide end switches or proportioning controllers permitting simultaneous operation or interlocking with other equipment.

f. Provide separate electrical circuits for damper operators with no more than four (4) operators on a circuit.

5. Coordinate with dampers provided:

a. Provide damper operators that are rated for the required torque.

b. If single damper operator can not meet torque requirement, provide sectional dampers to match operator torque.

6. Use of electric operators shall be limited to small dampers in those applications where it is impractical to provide pneumatic operators and are to be approved by the ENGINEER.

7. Ensure coordination to provide for the installation of tight closing dampers low leakage type (6 cfm per square foot at 4 inches WC pressure across damper) with compatible dampers, damper operators and related controls.

C. Motor-Operated Valves:

1. Valves shall have modulating plugs and contoured disc type inner valve construction to ensure modulation of flow and shut-off features as the application demands.

2. Furnish valves 2 inches and smaller with high grade bronze bodies with screwed ends.

a. Reducers and fittings necessary to install smaller than pipe size valves shall be furnished and installed under applicable piping sections.

3. Furnish valves 2-1/2 inches and larger with iron bodies with flanged ends.

a. Rate valves at a maximum fluid pressure of 125 pounds per inch, and a maximum fluid temperature of 350 degrees F.

b. Valves to be sized in accordance with flow capacity and pressure drop indicated.

Fluid	Inlet Pressure	Differential Pressure
Chilled water	25 psig	5 feet

4. Furnish valves for chilled water with equal percentage modulating plugs and renewable composition discs.

a. Coil valves shall be molded rubber diaphragm type. b. Valves 2 inches and smaller shall be screwed.

c. Valves 2-1/2 inches and larger shall be flanged. d. Valve bodies suitable for 125 psig WP

e. Provide three-way mixing or diverting valves as indicated or as the application demands.

D. Valve Operators:

1. Provide operators of proper size and number to secure true throttling or two- position action as required.

2. Provide electric operators with fully immersed in oil gear train, in tightly closed cast aluminum housing.

a. Provide valve linkage.

3. Schedule:

Valve No.	GPM	Valve C v	Valve Type	Size, IN
15LFV972	47.9	32.6	3-way	1 1/4

E. Electric Control Instruments:

1. Provide stainless steel sensing elements type thermostats with liquid filled, compensated thermal systems so that equally spaced dial graduations are possible over entire range.

a. Make thermal systems field detachable with averaging or plain bulbs as installation conditions dictate.

b. Provide sensing elements minimum of 60 inches in length and suitable for operation from -30 to 300 degrees F.

c. Provide reverse acting on-off type thermostats for controlling ventilating fans.

d. Provide multiple stage thermostats where designated in Paragraph

"Sequence of Operation."

2. Provide transformers for supplying current to control equipment operating at less than 120 V and where required by manufacturer's automatic control system design capable of supplying 125 percent of energy requirements of equipment connected for not less than 1 hour.

a. Enclose transformers in UL listed cabinets with conduit connections.

b. Provide fused disconnect switches on both primary and secondary sides. c. Provide in full compliance with Division 16, Electrical, Specifications.

3. Provide low limit electric thermostats of two-position type with 20-foot bulb and manual reset.

a. Shall be capable of opening thermostat circuit if any 1-foot section of bulb is subjected to a temperature below thermostat setting

b. Each thermostat shall have two (2) circuits, one (1) to shut down fan, and another for alarm.

c. Install all freeze-stats to override starter circuits regardless of position.

d. For corrosive environments provide thermostats with stainless steel sensing elements.

1) Ensure element is installed to sense coldest point should stratification occur.

4. Provide each thermostat with an accurate red-reading thermometer sensing temperature outside of enclosure.

5. Label thermostat with identification tag of HVAC equipment controlled using phenolic nameplate in accordance with Specification Section 10400, Identifying Devices.

F. Industrial Controllers:

1. Provide control instruments, devices, and incidentals of industrial process control quality capable of producing the outlined performances.

2. Electronic (and electric) controller shall have three (3) control mode capabilities of proportional rate (time), and dead band within following minimum performance and application criteria:

a. Setpoint Adjustment: 0 percent to 110 percent of span.

b. Repeatability: Setpoint repeats within +0.1 percent of span.

c. Dead Band: 1 percent of span, standard.

d. Rate: 5 to 30 seconds adjustable.

e. Response Level: 50 milliseconds for a step change of 1 percent of span beyond setpoints.

f. Output: SPDT relay contacts, 5 amps at 117 Vac noninductive.

3. Controller shall be capable of remote setpoint adjustment, permanently mounted in air flow control panel unless otherwise indicated.

4. Provide each controller with instruments (pressure gauges, milliampmeters, voltmeters, etc.) to indicate magnitude of output signal in both medium of signal (psig, mA, volt DC, etc.) and percentage of full output signal.

G. Static Pressure Gauges:

1. Install gauges on control panel for each system.

a. One (1) gauge shall serve each filter while others shall serve as a check on system.

b. Gauges shall be Magnahelic by Dwyer 2000 ASF, Ashcroft, or equal, flush mounted with signal flag for filter gauge.

c. Install static pressure tips as scheduled under control panel indication points. d. Static pressure ranges:

1) Filter (Cartridge): 0 to 2.0 inches WC.

2) Air-Handling and Air Conditioning Systems: 0 to 10.0 inches WC (one

(1) per air-handling unit).

H. Airflow Sensors: See Section 17405, Process Instrumentation and Control. I. HVAC Control Panels (15LFCP950, 15JFCP961):

1. Panels shall conform to the requirements of Section 16442, Control Panels, and shall be floor or wall-mounted and be sized to accommodate electrical switches, protective devices (except electrical switches and devices furnished as an integral part of air handling equipment).

2. Mount indicating controllers or receiver-controllers, three-way air valves, relay, EP and PE switches, switching relays, ammeters and other accessory items on local sub-panels set in vicinity of equipment to be served.

a. Where two (2) similar items of equipment, such as pumps, are installed adjacent to each other a single panel may be used to contain all instruments.

3. Fully compensated capillaries connected to instruments shall be of sufficient length to allow them to be run between equipment and placed in such a position so that they will not obstruct service of equipment or become damaged.

4. Temperatures, pressures, equipment operation, and related items shall be continuously indicated on panels.

5. Miniature milliamp meters for electronic temperature transmission may be used.

6. Mount all relays, PE switches, pressure switches, etc., on rear inside of enclosure.

a. Tag each instrument corresponding to symbols used on control diagrams.

7. Temperatures, pressures, equipment operation, and related items shall be continuously indicated on panels.

8. Points to be monitored are scheduled in the Control Sequences and as shown on

Drawings.

9. Provide 120 V power, control, and monitoring to and from temperature control panel for the following devices:

a. Smoke detectors. b. Flow switches.

c. Temperature control valves. d. Temperature transmitters.

e. Thermostats.

f. Miscellaneous fans, dampers, and valve actuators as shown on Drawings. g. Associated equipment.

10. Provide motor starters for 120V equipment.

11. Provide all wiring and conduit between the local temperature control panel and associated equipment.

12. Local temperature control panel shall be a programmable direct digital control

(DDC) system:

a. Battery backup.

b. Provide adequate I/O modules to perform the control functions shown and specified with 20 percent excess capacity.

PART 3 - EXECUTION

3.1 INSTALLATION

A. Comply with requirements of Specification Section 16120, Conductors and Cables, and Specification Section 16130, Raceway Systems and Pull Boxes.

B. Identification: See Specification Section 10400, Identifying Devices.

C. Connect control devices to perform functions indicated and perform in required sequence.

D. Use remote element temperature transmitters for points of temperature transmitters for points of temperature measurement occurring in air ducts or shafts, or in mechanical piping system.

E. Use remote element pressure transmitters of panel-mounted pressure gauges.

F. Where continuous indication of space temperature is on local control panels, install a thermostat and a temperature transmitter side by side.

1. Pipe continuous indication signal to a receiver on panel.

2. A resistance element or thermocouple signal may be used with continuous indicating meter, calibrated in degrees F.

G. In general, locate thermostats for room control immediately inside door, above light switch, unless shown otherwise.

1. Where light switch is in an entryway to room, locate thermostat on wall within room so it is capable of sensing true space conditions.

2. Prior to installation, coordinate thermostat location with ENGINEER. H. Mount local control panels adjacent to equipment served.

I. Where a temperature indicating gauge is used at the panel, a pressure gauge indicating transmitter signal is not required.

J. Provide appropriate type continuous reading indicator for each controller, transmitter and transducer.

1. Mount in-line or tapped on controller.

2. Mount at local control panel.

K. Gauges with flexible hose terminating with hypodermic needle may be used for checking control system.

1. Do not substitute for in-line gauges.

L. Locate panels so visual observation and adjustment can be accomplished from floor level.