A02 Attachment B - Chiller Specifications-2022-05-25.docx

SECTION 23 64 16.16 (MasterFormat 2016) Water-Cooled Centrifugal Water Chillers

PART 1 - GENERAL

1.01 SECTION INCLUDES

A. Semi-hermetic, water-cooled, direct-drive centrifugal chillers that shall use HFO-514A.

1.02 SUBMITTALS

A. Acceptable refrigerants on which chiller performance is based are HFO-514A and HFO-513A. All proposals for chiller performance must include an AHRI approved selection method for the specified refrigerants.

B. Submit drawings indicating assembled dimensions, operating weight, load distribution, and required service and access clearances.

C. Submit product data indicating options and specialties, electrical requirements, and wiring diagrams and connections. Indicate accessories, valves, strainers, and thermostatic valves required for the complete system.

D. Submit rigging, installation, and startup procedures. Include operations and maintenance data for both the chiller and starter or variable-speed drive. Include location, size, and type of field piping connections.

E. Submit performance data indicating energy input versus cooling load output from 100 to 25 percent of full load with constant entering condenser water temperature.

F. Submit compressor and product data in table form indicating impeller speed (RPM), number of bearings, type of bearings, high speed impeller shaft RPM, sound pressure level per AHRI 575-2008 (dB), number of stages, number of sets of inlet guide vanes, amount of refrigerant charge (lb), and amount of oil required (gal).

1.03 REGULATORY REQUIREMENTS

A. Conform to AHRI Standard 550/590 code for rating and testing of water chillers.

B. Conform to UL 1995 for Safety for Heating and Cooling Equipment.

C. Conform to ANSI/ASME SECTION VIII Boiler and Pressure Vessel Code for construction and testing of centrifugal chillers as applicable.

D. Conform to latest revision of ANSI/ASHRAE STANDARD 15 code for construction and operation of centrifugal chillers.

E. Unit shall bear the AHRI Certification Label for the specific type of water chiller as applicable.

1.04 DELIVERY, STORAGE, HANDLING AND EQUIPMENT ROOM REQUIREMENTS

A. Comply with manufacturer's installation instructions for rigging, chiller loading, local transportation requirements, unloading, storage, and final setting.

B. Protect chiller and controls from physical damage. Leave factory shipping covers in place until installation. The entire unit must be shrink wrapped with an environmentally recyclable material standard. The material shall include an imbedded desiccant to minimize/eliminate internal moisture.

C. The chiller shall ship with a dry nitrogen charge to eliminate potential charge loss during delivery and construction. The refrigerant must be shipped separately from the chiller. The refrigerant monitoring system shall be active at the job site prior to the charging of the chiller.

D. The chiller should ship with a full charge of oil.

E. Equipment Room Requirements

1. Follow minimum standards for refrigeration systems as required by the latest revision of ANSI/ASHRAE Standard 15, paying special attention to requirements for air monitoring, ventilation, self-contained breathing apparatus, and leak detection to assure the safety of chiller plant operating personnel.

2. Install proper outside exhaust of chiller refrigerant relief device(s), discharge header(s), and purge unit(s). Route exhaust to the outside of the building and away from all air intakes in compliance with the latest revision of ANSI/ASHRAE Standard 15.

3. Per ASHRAE Standard 147, medium pressure units with relief valves only shall have rupture discs in series with relief valves to minimize refrigerant leakage.

4. Field-install as required a refrigerant monitor that can be calibrated for appropriate refrigerant(s), capable of detecting concentrations of minimum ppm for low-level leak detection to assure the safety of chiller plant operating personnel.

5. Field-install as required suitable audible and visual alarms that activate well below the Acceptable Exposure Level (AEL) of the specific refrigerant(s) to alert persons inside and outside of the equipment room that a refrigerant leak condition exists.

6. Storage: Per ASHRAE Standard 147, positive pressure units must have a pumpdown capability that isolates the refrigerant charge for storage in a suitable vessel. If pump down capability does not exist, then the charge must be removed during long idle periods.

1.05 WARRANTY

A. Provide a standard unit parts and labor warranty for one year from startup or 18 months from shipment, whichever occurs first.

B. The original equipment purchase shall provide an optional refrigerant warranty for the duration of the 1st year. This warranty will provide for replacement refrigerant, if needed and if the reason for refrigerant loss is found to be a defect in material or workmanship, to restore a unit to the proper refrigerant charge. Replacement parts and labor to add the refrigerant are not covered under this warranty.

C. A quote for a 10-year parts, labor, and refrigerant warranty must be supplied by the manufacturer to provide a comparative value of confidence in reliability. This quote must be of the manufacturer's warranty; third party insurance/warranty quotes are not acceptable. The quoted warranty must cover the following items as a minimum:

1. Refrigerant.

2. Frequency drive if present.

D. Leak Tight Warranty: Provide as part of the chiller scope a refrigerant loss warranty for the lesser of 60 months from initial start-up or 66 months from date of shipment. During this period, manufacturer shall furnish replacement refrigerant which is lost due to a leak in the machine. Once a leak is determined, action must be taken (acceptable to the manufacturer) to eliminate the source of the leak. Replacement parts and labor are not covered under this warranty. If the chiller is placed under a comprehensive service and maintenance agreement from the original equipment manufacturer prior to the expiration of the standard refrigerant loss warranty, the refrigerant loss coverage shall continue as long as an active service and maintenance agreement from the manufacturer remains in effect without interruption. If a 10-Year Parts, Labor and Refrigerant Warranty is purchased from the original equipment manufacturer and if the chiller is placed under a comprehensive service and maintenance agreement from the original equipment manufacturer prior to the expiration of the 10-Year Parts, Labor and Refrigerant Warranty, the refrigerant loss coverage shall continue as long as an active service and maintenance agreement from the manufacturer remains in effect without interruption.

1.06 MAINTENANCE SERVICES

A. All inspections and service of units shall be accomplished by factory trained and authorized servicing technicians.

B. All labor for leak checking the chiller according to the manufacturer's IOM and documentation must be included.

C. Include maintenance items as recommended in manufacturer's operating and maintenance data.

D. Submit copy of service call work orders and summary report to the owner, including description of work performed, operating performance status and noted exceptions.

1.07 VERIFICATION OF CAPACITY AND EFFICIENCY

A. PERFORMANCE TOLERANCES

1. The following allowable tolerances must be followed:

a. The tolerance on allowable capacity must be as defined by AHRI Standard 550/590.

b. The IPLV/NPLV and full load tolerances are as defined by AHRI Standard 550/590, and the tolerances at full load and all part load test points must also be as defined by AHRI Standard 550/590 if applicable.

PART 2 - PRODUCTS

2.01 SUMMARY

A. Description: Factory-assembled and tested water chiller complete with compressor, evaporator, condenser, controls, starter or variable frequency drive, interconnecting unit piping and wiring, indicating accessories, and mounting frame. Performance shall be per specification section 3.03 schedule.

B. The contractor shall furnish and install centrifugal water chillers. The units shall produce the specified tonnage per the scheduled data in accordance with the latest revision of AHRI 550/590. The unit shall bear the AHRI certification label as applicable.

C. Unit shall be painted in accordance with the manufacturer's standard procedures and practices.

2.02 COMPRESSOR AND MOTOR

A. The compressor shall be centrifugal with single or multiple stages.

B. Low or medium pressure refrigerant machines shall be provided when available.

C. Chiller should be able to unload to 25.00 % of design tonnage with constant entering water temperature.

D. Compressor assembly shall be vibration tested at the factory. Vibration shall not exceed 0.15 inches per second at full load design compressor speed as measured on the motor housing. The test data shall be recorded and provided to the customer for approval.

E. The motor shall be hermetic and either suction or liquid refrigerant cooled. Hot gas motor cooling is not acceptable.

F. Motors shall have winding 100 ohm platinum RTDs for temperature sensing on each phase. Thermistors and thermal overloads are not acceptable. These temperatures shall be furnished to the unit control panel for monitoring and alarm.

G. Manufacturers with speed increasing transmissions shall not exceed 10,000 RPM compressor speeds and shall annually inspect the gears and all bearings. A report shall be forwarded to the owner each year over the first five years to confirm completion.

H. If the manufacturer uses electronic (i.e. magnetic) bearings a 10 year warranty on all chiller compressor capacitors must be provided I. The impellers shall be fully shrouded and made of a high strength aluminum alloy. Impellers shall be dynamically balanced and over-speed tested at 1.25 times impeller shaft speed.

2.03 EVAPORATOR (CHILLER BARREL)

A. The evaporator and condenser shall be built in accordance with ANSI/ASHRAE 15-2001 Safety Code for Mechanical Refrigeration and ASME section VIII as applicable.

B. Evaporator tubes shall be internally and externally enhanced with a 1.00" outer diameter. The tubes shall be securely supported at intermediate supports and physically expanded into both ends of the tube sheets.

1. The minimum evaporator tube wall thickness, root-to-root across the entire tube length shall be 0.025". It is unacceptable to provide this thickness at the intermediate supports only.

C. The evaporator water piping connections shall be grooved.

D. The evaporator waterboxes shall be standard non-marine type with connections per the schedule.

E. Supply and return head waterboxes shall be designed for a working pressure of 150 psi and shall be factory hydrostatic pressure tested at 150 percent of the design pressure. Provide drain and vent connections in water boxes.

F. Factory applied insulation is required at the time the chiller is shipped from the factory.

G. Units with multi-stage compressors shall incorporate an interstage flash vessel "economizer". All units with single stage compressors shall have the condensers circuited for liquid subcooling and be provided with a thermometer well to monitor the amount of subcooling.

H. Adjustable or float type refrigerant metering devices and thermal expansion valves shall be inspected and adjusted by the manufacturer at the end of each year for the first five years of operation to assure equivalent reliability and maintenance to a fixed orifice system. A written report shall be forwarded to the owner each year to confirm completion.

2.04 CONDENSER

A. The condenser shall be built in accordance with ANSI/ASHRAE 15-2001 Safety Code for Mechanical Refrigeration and ASME section VIII as applicable.

B. Condenser tubes shall be internally and externally enhanced with a 0.75" outer diameter. The tubes shall be securely supported at intermediate supports and physically expanded into both ends. The condenser tubes must also be removable from both ends to provide easy access for tube changeouts or tube cleaning.

1. The minimum condenser tube wall thickness, root-to-root across the entire tube length shall be 0.028". It is unacceptable to provide this thickness at the intermediate supports only.

C. The condenser water piping connections shall be grooved.

D. The condenser waterboxes shall be standard non-marine type with connections per schedule.

E. Supply and return head waterboxes shall be designed for a working pressure of 150 psi and shall be factory hydrostatic pressure tested at 150 percent of the design pressure. Provide drain and vent connections in water boxes.

2.05 REFRIGERANT

A. Acceptable Refrigerants on which chiller performance is based are low-GWP, next generation refrigerants such as R-513A or R-514A.

B. Refrigeration Transfer: Provide service valves and other factory-installed accessories required to facilitate transfer of refrigerant from the chiller to remote systems.

1. See Section 1.04 for additional details on refrigerant shipment.

C. Refrigerant Flow Control: Fixed orifice plates at the entrance and exit of the economizer shall be used to control refrigerant flow.

D. Low pressure chillers: Chillers that operate at low pressures must have a high efficiency purge system to ensure that any potential non-condensable leakage into the vessel is immediately eliminated. The purge run time shall be monitored by the main unit controller to act as a leak detector if required, and must have the following specifications:

1. The manufacturers of low pressure machines must provide a purge system.

2. The purge efficiency must meet ASHRAE Standard 147-2002.

3. The purge shall be capable of operating when the chiller is idle in accordance with ASHRAE Standard 147-2002.

2.06 ELECTRICAL

A. Chiller shall be installed, wired, and functionally tested at the factory before being shipped.

B. Single point power connection - A control power transformer internal to the motor controller/frequency drive and of sufficient size to power all chiller mounted auxiliary loads shall be supplied. No separate power connection shall be required for chiller mounted equipment. The CPT shall tap from the main power connection.

C. Terminal blocks are numbered to match the wiring diagram must be included.

2.07 CONTROLS

A. The chiller shall be controlled by a unit mounted, stand-alone Direct Digital Control (DDC) system. A dedicated chiller microprocessor control panel is to be supplied with each chiller by the chiller manufacturer.

B. Enclosure shall be unit mounted NEMA 250 Type 1.

C. The chiller manufacturer shall include a pressure, non-mechanical based flow switch that is of the thermal dispersion type for each evaporator and condenser to verify flow through the unit.

D. A color, touch sensitive liquid crystal display (LCD) shall be unit mounted and a minimum of 12.1" diagonal. The display shall be fully adjustable in height and viewing angle. Animated graphical representations of chiller subsystem operation shall be used to enhance the user interface.

E. Display shall consist of a menu driven interface with easy touch screen navigation to organized sub-system reports for compressor, evaporator, condenser, purge and motor information as well as associated diagnostics. The controller shall display all active diagnostics and a minimum of 20 historical diagnostics.

F. The chiller control panel shall provide control of chiller operation and monitoring of chiller modules, sensors, actuators, relays and switches. The chiller control panel shall include controls to safely and efficiently operate the chiller.

G. Control authority must be capable of handling at least four conditions: Off, local manual at the chiller, local automatic at the chiller and automatic control through a remote source.

H. Capability to connect a laptop to service utility with applicable software from manufacturer and obtain enhanced set-up and diagnostics.

I. The front of the chiller control panel shall display the following in clear language, without the use of codes, look-up tables, or gauges:

1. Run time.

2. Number of starts.

3. Current chiller operating mode.

4. Chilled water set point and set point source.

5. Electrical current limit set point and set point source.

6. Entering and leaving evaporator water temperatures.

7. Entering and leaving condenser water temperatures.

8. Saturated evaporator and condenser refrigerant temperatures.

9. Evaporator and condenser refrigerant pressure.

10. Oil tank temperature.

11. Oil tank pressure.

12. Oil pump discharge pressure.

13. Differential oil pressure.

14. Compressor motor current per phase.

15. Compressor motor percent RLA.

16. Compressor motor voltage per phase.

17. kW energy consumption and power factor.

18. Compressor motor winding temperatures per phase.

19. Purge operating mode.

20. Purge operating status.

21. Time until next purge run.

22. Daily pumpout - 24 hours.

23. Average daily pumpout - 7 Days.

24. Purge refrigerant compressor suction temp.

25. Purge liquid temp (chiller condenser saturated refrigerant temperature).

26. Daily pumpout limit/alarm.

J. The chiller control panel shall provide password protection of all setpoints.

K. The controller shall have the ability to display all primary sub-system operational parameters on dedicated trending graphs. The operator must be able to create up to 6 additional custom trend graphs, choosing up to 10 unique parameters for each graph to trend log data parameters simultaneously over an adjustable period and frequency polling.

L. The chiller control panel shall provide individual relay outputs to start/stop the evaporator and condenser water pumps. The condenser water pump relay output can be used to enable the cooling tower temperature controls.

M. The chiller control panel shall provide leaving chilled water temperature reset based upon return water temperature.

N. The chiller control panel shall be capable of displaying system data in I-P or SI units.

O. Safeties - the chiller control panel shall provide the following safeties:

1. Low chilled water temperature.

2. Low evaporator refrigerant temperature or pressure.

3. High condenser refrigerant pressure.

4. Evaporator and condenser water flow status.

5. Low oil pressure.

6. Low oil temperature.

7. High oil temperature.

8. High motor winding temperatures.

9. High motor current.

10. Starter/VFD function faults.

11. Sensor faults.

12. Unit controls operation.

13. The chiller control panel or starter shall incorporate advanced motor protection to safeguard the motor throughout the starting and running cycles from the adverse effects of:

a. Current phase loss.

b. Current phase unbalance.

c. Current phase reversal.

d. Under/Over voltage.

e. Motor current overload.

f. Distribution fault protection with auto restart consisting of three-phase current sensing devices that monitor the status of the current.

g. Starter contactor fault protection.

h. Starter transition failure.

P. The chiller control panel shall provide evaporator freeze protection and low limit control to avoid low evaporator refrigerant temperature trip-outs during critical periods of chiller operation. Whenever this control is in effect, the controller shall indicate that the chiller is in adaptive mode. If the condition exists for more than 30 seconds, a limit warning alarm relay shall energize.

Q. The chiller control panel shall be capable of providing short cycling protection.

R. The chilled water controller of each chiller shall include variable water-flow capability to allow the chiller to respond quickly to accelerating or decelerating water, and have the following features:

1. The variable water-flow compensation capability shall allow control of the leaving chilled water temperature to within +/- 1.0°F (0.6°C) at a water flow rate change of 10% per minute and will stay online at a water flow rate change of 30% per minute.

S. The chiller time to fully load up to 80% shall be no longer than 5 minutes. The manufacturer shall supply documentation to support their ability to do this.

1. If the documentation is not adequate, the manufacturer must demonstrate this in the factory on an AHRI certified loop.

2. See Section 2.13 for more information on restart demonstration.

T. The chiller control panel shall provide hardwire connections for the following binary and analog signals:

1. Compressor Running.

2. Detection by the panel of a fault requiring manual reset.

3. Chiller operation at maximum capacity.

4. Chiller operation in condenser limit mode and thereby requesting condenser water temperature relief.

U. The chiller control panel shall provide an analog [2 - 10VDC] [4 - 20mA] output signal that shall indicate the Compressor Motor Percent RLA.

V. The chiller should have a condenser pressure output signal of [0 - 10VDC] [4 - 20mA] that may be used for head pressure control if required.

W. The chiller control panel shall allow for an analog input for a chilled water setpoint and an electrical current limit set point. These setpoints can be in the form of 4-20 mA or 2-10 Vdc signals from a remote source (i.e. generic building automation system).

X. The chiller controller shall communicate directly to the control panel

2.08 FREQUENCY DRIVES AND STARTERS

A. LOW VOLTAGE VARIABLE FREQUENCY DRIVE (VFD), REMOTE MOUNTED

1. The centrifugal water chiller shall be furnished with an air cooled variable frequency drive (VFD) as shown on the drawings. The VFD shall be remote (free standing) mounted and shipped completely factory assembled, wired and tested.

2. The VFD will be specifically designed to interface with the centrifugal water chiller controls and allow for the operating ranges and specific characteristics of the chiller. The VFD control logic shall optimize chiller efficiency by coordinating compressor motor speed and compressor inlet guide vane position to maintain the chilled water setpoint while avoiding surge. If a surge is detected, VFD surge avoidance logic will make adjustments to move away from and avoid surge at similar conditions in the future.

3. The VFD efficiency shall be 97% or better at full speed and full load. Fundamental displacement power factor shall be a minimum of 0.96 at all loads.

4. The VFD shall be solid state, microprocessor based pulse-width modulated (PWM) design. The VFD shall be voltage and current regulated. Output power devices shall be IGBT transistors.

5. The VFDs shall each be furnished in a Nema 1 metal enclosure having as minimum a short circuit current rating (SCCR) of 100,000 amps per UL 508. It will include three phase input lugs plus a grounding lug for electrical connections, output motor connection via factory installed bus bars and all components properly segregated and completely enclosed in a single metal enclosure.

a. Enclosure shall include a padlockable, door-mounted circuit breaker with shunt trip and AIC rating of 100,000 amps.

b. The entire chiller package shall be UL/CUL listed.

6. The VFD shall be tested to ANSI/UL Standard 508 and shall be listed by a Nationally Recognized Testing Laboratory (NRTL) as designated by OSHA.

7. Compliance to recommendations for harmonic mitigation - The VFD design shall include a DC link reactor on positive and negative rails to minimize power line harmonics and protect the VFD from power line transients.

8. Input shall be nominal 460. V, three phase, 60. Hz AC power, +/- 10 percent of nominal voltage.

9. Motor frequency range 38-60 hertz.

10. The VFD shall include the following features:

a. All control circuit voltages are physically and electrically isolated from power circuit voltage.

b. 150% instantaneous torque available for improved surge control.

c. Soft start, adjustable linear acceleration, coast-to-stop.

d. Insensitivity to incoming power phase sequence.

e. Adjustable current limiting and U.L. approved electronic motor overload protection.

f. Output line-to-line short circuit protection.

g. Line-to-ground short circuit protection.

h. Protection from phase loss at VFD input.

i. Protection from phase reversal/imbalance.

j. Protection from over/under-voltage.

k. Protection from over-temperature.

11. The following VFD status indicators shall be available to facilitate startup and maintenance:

a. Input line voltage.

b. Output/load amps.

c. Fault.

12. Service Conditions:

a. Operating ambient temperature of 14°F - 104°F (-10°C - 40°C).

b. Room ambient up to 95% relative humidity.

c. Elevation to 3300 feet (1000 meters). For every 300 feet (90 meters) above 3300 feet, the rated output current shall be decreased by 4% up to 9900 feet (3000 meters)

PART 3 - EXECUTION

3.01 INSTALLATION

A. Install in accordance with manufacturer's instructions.

B. Provide for connection to electrical service. Include for connection of oil pump if required.

C. Provide for connection of electrical wiring between starter and chiller control panel, oil pump, and purge unit.

D. Furnish and install necessary auxiliary water piping for oil cooling units if required.

E. Arrange piping for easy dismantling to permit tube cleaning.

F. Provide piping from chiller relief device to outdoors. Size as recommended by manufacturer.

3.02 MANUFACTURER'S FIELD SERVICES

A. All Startup, maintenance and monitoring functions shall be performed by a manufacturer's commercial agent to confirm, (in writing), that equipment has been correctly installed and passes specification checklist prior to equipment becoming operational and covered under OEM warranty.

B. The manufacturer shall furnish complete submittal wiring diagrams of the chiller(s) starter(s) and associated components like cooling towers, pumps, interlocks, etc. as applicable for field maintenance and service.

1. STARTUP - Provide all labor and materials to perform the startup. This shall be done in strict accordance with manufacturer's specifications and requirements.

a. Provide a complete log of all operating parameters.

b. Assure actual performance matches with submittals and computerized selection programs for other than submittal conditions.

c. Submit a hard copy of the service report and logs.

2. TRAINING - Provide a minimum of four hours of training that is a combination of classroom and hands on instruction.

3. INSPECTIONS - For the duration of the warranty, during operation, there shall be inspections in 3 month intervals, to perform the following:

a. Check the general operation of the unit.

b. Provide a complete log as in item 2 above.

c. Check operation of the control circuit.

d. Check operation of the lubrication system.

e. Check operation of the motor and starter.

f. Analyze the record data. Compare the data to the original design conditions.

g. Review operating procedures with operating personnel.

h. Do one oil analysis and submit the written report. Change the oil and filter as required in the published manufacturer's literature.

i. Complete all recommended maintenance and tests as documented in the manufacturer's published literature.

j. Provide a written report of completed work, operating log, and indicate any uncorrected deficiencies.

k. At the final inspection (performed within 30 days of warranty expiration), assure that the chillers are functioning correctly and that all warranty items are resolved to the customer's satisfaction.

3.03 SCHEDULE

Evaporator:

Condenser:

Compressor:

Starter:

END OF SECTION