236400 Packaged Water Chillers.doc

Upgrade Chiller Plant @JLM: Project 1

JLM Memorial Veterans Hospital 598-19-101

04-01-11

Construction Documents

2020.12.30

SECTION 23 64 00

PACKAGED WATER CHILLERS

PART 1 ‑ GENERAL

1.1 DESCRIPTION

A. Semi-hermetic, water-cooled, direct-drive centrifugal chillers.

1.2 RELATED WORK

B. Section 00 72 00, GENERAL CONDITIONS.

C. Section 01 00 00, GENERAL REQUIREMENTS.

D. Section 01 33 23, SHOP DRAWINGS, PRODUCT DATA, and SAMPLES.

E. Section 13 05 41, SEISMIC RESTRAINT REQUIREMENTS FOR NON-STRUCTURAL COMPONENTS.

F. Section 23 05 11, COMMON WORK RESULTS FOR HVAC.

G. Section 23 21 23, HYDRONIC PUMPS.

H. Section 23 05 41, NOISE and VIBRATION CONTROL FOR HVAC PIPING and EQUIPMENT.

I. Section 23 21 13, HYDRONIC PIPING.

J. Section 23 31 00, HVAC DUCTS and CASINGS

K. Section 23 05 12, GENERAL MOTOR REQUIREMENTS FOR HVAC.

L. Section 26 29 11, LOW-VOLTAGE MOTOR STARTERS.

M. Section 01 91 00, GENERAL COMMISSIONING REQUIREMENTS

N. Section 23 08 00, COMMISSIONING OF HVAC SYSTEMS: Requirements for commissioning, systems readiness checklists, and training.

1.3 Definition

O. Engineering Control Center (ECC): The centralized control point for the intelligent control network. The ECC comprises of personal computer and connected devices to form a single workstation.

P. BACNET: Building Automation Control Network Protocol, ASHRAE Standard 135.

Q. Ethernet: A trademark for a system for exchanging messages between computers on a local area network using coaxial, fiber optic, or twisted-pair cables.

R. FTT-10: Echelon Transmitter-Free Topology Transceiver.

1.4 QUALITY ASSURANCE

S. Refer to Paragraph, QUALITY ASSURANCE, in Section 23 05 11, COMMON WORK RESULTS FOR HVAC, and comply with the following.

T. Refer to PART 3 herein after and Section 01 00 00, GENERAL REQUIREMENTS for test performance.

U. Comply with AHRI requirements for testing and certification of the chillers.

V. Refer to paragraph, WARRANTY, Section 00 72 00, GENERAL CONDITIONS, except as noted below:

Chiller manufacturer shall provide a whole unit parts, labor and refrigerant warranty for a period of 10 years from start-up. The warranty must be provided by the manufacturer; third party insurance/warranty coverage is not acceptable. The chiller manufacturer shall provide an original factory warranty certificate for each chiller listing the chiller model, serial number, and warranty information as specified. Warranty coverage will by the factory, not local sales offices. A factory employee will provide all warranty and preventive maintenance services. The warranty will cover all items provided by the manufacturer of the chiller including variable frequency drive, refrigerant, motor and starter, shaft seals if present, and heat exchangers.

Warranty shall begin at Start up of the chillers.

W. Refer to OSHA 29 CFR 1910.95(a) and (b) for Occupational Noise Exposure Standard

X. Refer to ASHRAE Standard 15, Safety Standard for Refrigeration System, for refrigerant vapor detectors and monitor.

1.5 APPLICABLE PUBLICATIONS

Y. The publications listed below form a part of this specification to the extent referenced. The publications are referenced in the text by the basic designation only.

Z. Air Conditioning, Heating and Refrigeration Institute (AHRI):

370-01 Sound Rating of Large Outdoor Refrigerating and Air-Conditioning Equipment

495-1999 (R2002) Refrigerant Liquid Receivers

550/590-03 Standard for Water Chilling Packages Using the Vapor Compression Cycle

575-94 Methods for Measuring Machinery Sound within Equipment Space

Units shall bear the AHRI Certification Label

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

ANSI/ASHRASE-15-2007

Safety Standard for Mechanical Refrigeration Systems

GDL 3-1996

Guidelines for Reducing Emission of Halogenated Refrigerants in Refrigeration and Air-Conditioning Equipment and Systems

AB. American Society of Mechanical Engineers (ASME):

ASME Boiler and Pressure Vessel Code, Section VIII, "Pressure Vessels - Division 1"

AC. American Society of Testing Materials (ASTM):

C 534/ C 534M-2008 Preformed, Flexible Elastomeric Cellular Thermal Insulation in Sheet and Tubular Form

C 612-04 Mineral-fiber Block and Board Thermal Insulation

AD. National Electrical Manufacturing Association (NEMA):

250-2008 Enclosures for Electrical Equipment (1000 Volts Maximum)

AE. National Fire Protection Association (NFPA):

70-2008 National Electrical Code AF. Underwriters Laboratories, Inc. (UL):

1995-2005 Heating and Cooling Equipment

1.6 WARRANTY SERVICES

AG. Warranty Services shall be provided to the owner to cover all Warranty Services required for the chiller for 10 years from start up. This Warranty Service, in conjunction with the OEM Warranty, shall result in a 10 year, no cost to owner for service or repair on the chillers. The Service will not be deferred to a local agent/representative but must be provided by an employee of the manufacture. All inspections and service of units shall be accomplished by factory trained and authorized servicing technicians.

AH. Scope of work shall cover:

Four (4) site visits per year to inspect and log all chillers.

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

All items that a manufacturer recommends changing based on a schedule or use in the first 10 years. Including oil, filters, gaskets, bearings, capacitors and any other items that may need to be changed to maintain operational reliability.

Maintain EPA certified refrigerant log for total amount added/removed/lost for each chiller. Service provider shall keep a copy and provide a copy to the owner when requested.

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

Condenser Tube Cleaning for each chiller shall be included once (1) per year during the annual maintenance.

Evaporator Tube Cleaning for each chiller is not required to be included.

1.7 EFFICIENCY REQUIREMENTS

AI. PERFORMANCE TOLERANCES

The following allowable tolerances must be followed:

The tolerance on allowable capacity is as defined by AHRI Standard.

The IPLV/NPLV and full load tolerances must be as defined by AHRI Standard, and the tolerances at full load and all part load test points must also be as defined by AHRI Standard. The tolerances for kW/ton at all points shall be as defined by AHRI Standard.

1.8 SUBMITTALS

AJ. Submit in accordance with Specification Section 01 33 23, SHOP DRAWINGS, PRODUCT DATA, and SAMPLES.

AK. Manufacturer's Literature and Data.

Centrifugal water chillers, including motor starters, control panels, and vibration isolators, and remote condenser data shall include the following:

a. Rated capacity.

b. Pressure drop.

c. Efficiency at full load and part load without applying any tolerance indicated in the AHRI 550/590/Standard. Submit performance data indicating energy input versus cooling load output from 100 to 25 percent of full load with constant entering condenser water temperature.

d. Refrigerant

e. Accessories.

f. Installation instructions.

g. Start up procedures.

h. Wiring diagrams, including factor-installed and field-installed wiring.

i. Sound/Noise data report. Manufacturer shall provide sound ratings. Noise warning labels shall be posted on equipment.

j. Refrigerant vapor detectors and monitors.

k. Assembled dimensions, operating weight, load distribution, and required service and access clearances.

l. 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.

m. 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 575-3009 (dB), number of stages, number of sets of inlet guide vanes, amount of refrigerant charge (lb), and amount of oil required (gal).

AL. Maintenance and operating manuals for each piece of equipment in accordance with Section 01 00 00, GENERAL REQUIREMENTS.

AM. Run test report for all chillers.

AN. Product Certificate: Signed by chiller manufacturer certifying that chillers furnished comply with AHRI requirements. The test report shall include calibrated curves, calibration records, and data sheets for the instrumentation used in factory tests.

AO. Provide seismic restraints for refrigeration equipment to withstand seismic forces.

PART 2 ‑ PRODUCTS

2.1 SUmmary

AP. Description: Factory assembled and tested water chiller complete with compressor, evaporator, condenser, controls, starter or variable speed drive, interconnecting unit piping and wiring, indicating accessories, and mounting frame.

AQ. The contractor shall furnish and install centrifugal water chillers as shown and scheduled in the plans and specifications. 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.

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

2.2 COMPRESSOR AND MOTOR

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

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

AU. Chiller should be able to unload to 10 % of design tonnage with constant entering water temperature. The minimum unloading point shall be demonstrated at the time of the factory performance test. The machine shall be modified to include hot gas bypass if the minimum load cannot be met.

AV. Compressor assembly shall be vibration tested at the factory. Vibration shall not exceed 0.2 inches per second.

AW. The motor shall be hermetic and either suction or liquid refrigerant cooled. Hot gas motor cooling is not acceptable. Open drives are not acceptable due to the potential for refrigerant and oil leakage associated with the mechanical shaft seal and the coupling between an open motor and the compressor.

AX. Motors shall have winding 100 ohm platinum RTD's 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.

AY. 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.

AZ. The chiller manufacturer must provide a 20 year warranty on compressor capacitors per compressor.

BA. 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.

2.3 EVAPORATOR (CHILLER BARREL)

BB. 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.

BC. Evaporator 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 of the tube sheets. The evaporator tubes must also be removable from both ends to provide easy access for tube cleaning. 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.

BD. The evaporator water piping connections shall be grooved.

BE. The waterboxes shall be marine style. Side connections shall be provided such that the water piping of both the entering and leaving sides shall not be disconnected for mechanical cleaning. The water piping connections shall be in a direction perpendicular to the shells to allow full unblocked access to the tubes.

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

BG. Insulation will be 3/4" insulation and cover all low-temperature surfaces to include the evaporator, waterboxes, and suction elbow. Economizer, if applicable, is insulated with 3/8" insulation.

BH. Hinges shall be factory supplied on the both ends of the evaporator to facilitate waterbox removal without external rigging.

BI. 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.

BJ. 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.

BK. All evaporators shall be furnished with an integral inlet mist or liquid eliminator to prevent carryover of liquid refrigerant into the compressor.

2.4 CONDENSER

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

BM. 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. 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.

BN. The condenser water piping connections shall be grooved.

BO. The waterboxes shall be marine style. Side connections of the condenser and evaporator shall be provided such that the water piping of both the entering and leaving sides shall not be disconnected for mechanical cleaning. The water piping connections shall be in a direction perpendicular to the shells to allow full unblocked access to the tubes.

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

BQ. Hinges shall be factory supplied on both ends of the condenser to facilitate waterbox removal without external rigging.

2.5 ReFRIGERANT

BR. Acceptable Refrigerants on which chiller performance is based are HFO-1233zd(E) or any refrigerant with a GDP less than 150.

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

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

BU. Refrigerant Isolation for chillers using 134a. Factory install check or manual isolation valves in the compressor discharge line to the condenser and the refrigerant liquid line leaving the condenser to allow for isolation and storage of the full refrigerant charge in the chiller condenser shell. In addition, provide isolation valve on the suction side of compressor from evaporator to allow for isolation and storage of full refrigerant charge in the chiller evaporator shell.

BV. 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:

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

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

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

2.6 electrical

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

CA. 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.

CB. Terminal blocks with numbered and color coded wiring to match the wiring diagram must be included.

2.7 controls

CC. 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.

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

CE. 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.

CF. 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.

CG. 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.

CH. 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.

CI. 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.

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

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

Run time.

Number of starts.

Current chiller operating mode.

Chilled water set point and set point source.

Electrical current limit set point and set point source.

Entering and leaving evaporator water temperatures.

Entering and leaving condenser water temperatures.

Saturated evaporator and condenser refrigerant temperatures.

Evaporator and condenser refrigerant pressure.

Oil tank temperature.

Oil tank pressure.

Oil pump discharge pressure.

Differential oil pressure.

Compressor motor current per phase.

Compressor motor percent RLA.

Compressor motor voltage per phase.

kW energy consumption and power factor.

Compressor motor winding temperatures per phase.

Purge operating mode.

Purge operating status.

Time until next purge run.

Daily pumpout - 24 hours.

Average daily pumpout - 7 Days.

Purge refrigerant compressor suction temp.

Purge liquid temp (chiller condenser saturated refrigerant temperature).

Daily pumpout limit/alarm.

Bearing oil temperatures.

Discharge temperature (compressor).

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

CM. 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.

CN. 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.

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

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

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

Low chilled water temperature.

Low evaporator refrigerant temperature or pressure.

High condenser refrigerant pressure.

Evaporator and condenser water flow status.

Low oil pressure.

Low oil temperature.

High oil temperature.

High motor winding temperatures.

High motor current.

Starter/AFD function faults.

Sensor faults.

Unit controls operation.

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:

Current phase loss.

Current phase unbalance.

Current phase reversal.

Under/Over voltage.

Motor current overload.

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

Starter contactor fault protection.

Starter transition failure.

AFD/VFD communication-control failure.

CR. Compressor discharge temperature.

CS. High bearing temperatures.

Each of the compressor and motor bearings (including high speed, low speed, and thrust bearings) shall have factory installed, separate temperature sensors installed on the bearing or in the oil return line of each separate bearing.

If any oil temperature reaches or exceeds a set value, the chiller control panel shall shut down the chiller, display the diagnostic, and activate the front panel alarm indicator.

CT. 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.

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

CV. 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:

The variable water-flow compensation capability shall allow control of the leaving chilled water temperature to within +/- 0.5°F (0.3°C) at a water flow rate change of 10% per minute and will stay online at a water flow rate change of

CW. The chiller and controller shall include factory mounted transducers to read the differential evaporator water pressure (psid) and condenser water pressure (psid). The following parameters shall be displayed on the unit control display:

Evaporator differential pressure (psid).

Condenser differential pressure (psid).

Evaporator flow rate (GPM).

Condenser water flow (GPM).

Evaporator capacity (Tons).

CX. The chiller, upon power loss restoration, must be able to start the compressor within XX seconds. 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.

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

See Section 2.13 for more information on restart demonstration.

CY. The chiller control panel shall provide a relay output that shall energize whenever the compressor is running.

CZ. The chiller control panel shall provide an alarm relay output that shall energize whenever a fault requiring manual reset is detected by the panel.

DA. The chiller control panel shall provide a relay output that shall energize whenever the chiller is operating at maximum capacity.

DB. The chiller control panel shall provide a head relief request relay output to indicate that the chiller is in condenser limit mode and thereby requesting condenser water temperature relief.

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

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

DE. 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).

DF. The chiller control panel shall provide an analog output signal that shall indicate the condenser refrigerant pressure or condenser/evaporator differential refrigerant pressure.

DG. The chiller controller must be able to communicate directly to a building automation system using BACnet protocol (MSTP-RS 485).

2.8 frequency drives and starters

DH. LOW VOLTAGE, UNIT MOUNTED, STAR DELTA STARTER

Motor starter shall be a Star-Delta Closed Transition and shall have a NEMA 1A gasketed enclosure. The starter shall be UL 508 approved.

Motor starters shall include incoming line provisions for the number and size cables shown on the drawings. Incoming line lugs shall be copper mechanical type.

Contactors shall be sized properly to the chiller full load currents.

Each motor starter shall include a 4 KVA control power transformer with fused primary and secondary. Control relays shall be provided within the motor starter to interface with the control panel.

If the chiller main processor does not include an advanced motor protection system, the starter shall include an advanced motor protection system incorporating electronic three phase current overloads and current transformers. This electronic motor protection system shall monitor and protect against the following conditions:

Current phase loss.

Current phase unbalance.

Current phase reversal.

Under/Over line voltage.

Motor current overload during startup and running.

Momentary power loss protection with auto restart consisting of three-phase current sensing devices that monitor the status of the current. Restart inhibit is active and looks at motor RTDs to maximize starts/hour.

Starter contactor fault protection.

Starter transition failure.

Distribution fault protection.

The starter shall be able to operate in temperatures up to 104°F.

All field supplied wires, bus bars, and fittings shall be copper only.

The starter enclosure shall have a starter short circuit current rating (SCCR) of 65,000. If the starter enclosure does not have this SCCR rating, then a device shall be provided upstream of the starter to limit the fault current at the starter to be equal or less than the starter short circuit rating of the starter.

The following optional starter features shall be provided:

Circuit Breaker - Starter shall contain a circuit breaker capable of breaking currents up to its interruption capacity of 65,000 amperes (AIC). Operating handle and trip indicator shall be located on the door. This handle shall be capable of being padlocked.

Ammeters - A digital ammeter (3% minimum accuracy) shall be provided. Alternatively the amps (three phases) can be read at the chiller control panel.

Voltmeters - A digital ammeter (3% minimum accuracy) shall be provided. Alternatively, the volts (three phases) can be read at the chiller control panel.

Power Factor Correction Capacitors shall be provided to correct the power factor to 93.5% - 95.5% at full load conditions.

The starter shall offer ground fault protection.

The starter shall offer lightning protection via arrestors and surge capacitors.

DI. LOW VOLTAGE VARIABLE SPEED DRIVE (VSD), UNIT MOUNTED

The centrifugal water chiller shall be furnished with a liquid refrigerant cooled variable speed drive (VSD) as shown on the drawings. The VSD shall be factory mounted on the chiller and shipped completely factory assembled, wired and tested.

The VSD 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 VSD 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, VSD surge avoidance logic will make adjustments to move away from and avoid surge at similar conditions in the future.

The VSD 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.

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

Power semi-conductor and capacitor cooling shall be from a liquid cooled heatsink.

The centrifugal water chiller shall be furnished with a refrigerant cooled variable speed drive (VSD) to minimize maintenance and maximize cooling efficiency. If a water cooling design is used, especially an open loop condenser water design, a cleanable shell and tube heat exchanger must be supplied. Plate and frame heat exchangers are not allowed.

The VSDs shall each be furnished in a NEMA 1 metal enclosure having as minimum a short circuit current rating (SCCR) of 65,000 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.

Enclosure shall include a padlockable, door-mounted circuit breaker with shunt trip and AIC rating of 65,000 amps.

The entire chiller package shall be UL/CUL listed.

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

The VSD design shall include a standard integrated active rectification control system to limit total demand distortion (TDD) in current at the VSD to less than or equal to 5% as measured at the VSD input, in compliance to recommendations stated in IEEE 519-1992.

If optional active or passive filters are used to meet the less than or equal to 5% TDD, then the losses associated with the filter shall be included in the chiller performance on the selection (adjust penalties accordingly).

If a remote mounted filter is used to meet the less than or equal to 5% TDD, then the losses associated with the filter shall be included in the chiller performance on the selection (adjust penalties accordingly). Additionally, the remote filter must be brought in and tested along with the chiller for all applicable tests.

If a remote mounted filter is used and is required to be tested, the contractor is responsible for all associated installation costs of the remote filter for testing.

Input shall be nominal 480 volts, three phase, 60 hertz AC power, ± 10 percent of nominal voltage.

Line frequency 38-60 hertz.

The VSD shall include the following features:

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

150% instantaneous torque available for improved surge control.

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

Insensitivity to incoming power phase sequence.

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

Output line-to-line short circuit protection.

Line-to-ground short circuit protection.

Protection from phase loss at AFD input.

Protection from phase reversal/imbalance.

Protection from over/under-voltage.

Protection from over-temperature.

The following VSD status indicators shall be available to facilitate startup and maintenance:

Output speed in hertz and rpm.

Input line voltage.

Input line kW.

Output/load amps.

Average current in percent RLA.

Load power factor.

Fault.

VSD transistor temperature.

Service Conditions - at full output power:

No external venting or heat exchangers shall be required.

Operating ambient temperature of 32°F - 104°F (0°C - 40°C).

Room ambient up to 95% relative humidity.

Elevation up to 3300 feet (1000 meters). For every 300 feet (90 meters) above 3300 feet, the rated output current shall be decreased by 1%.

2.9 REFRIGERANT monitoring and safety equipment

DJ. General: Provide refrigerant monitoring sensor/alarm system and safety equipment as specified here. Refrigerant sensor and alarm system shall comply with ASHRAE Standard 15. The refrigerant monitoring system will be provided by the chiller manufacturer and shall be interfaced with the DDC control system.

DK. Refrigerant monitor shall continuously display the specific gas (refrigerant used) concentration; shall be capable of indicating, alarming and shutting down equipment; and automatically activating ventilation system. On leak detection by refrigerant sensor(s), the following shall occur:

Activate machinery (chiller) room ventilation.

Activate visual and audio alarm inside and outside of machinery room, with beacon light(s) and horn sounds equipment room and outside equipment room door(s). Shut down combustion process where combustion equipment is employed in the machinery room.

Notify Engineering Control Center (ECC) of the alarm condition.

DL. Refrigerant monitor shall be capable of detecting concentration of 1 part per million (ppm) for low-level detection and for insuring the safety of operators. It shall be supplied factory-calibrated for the apparent refrigerant.

DM. Monitor design and construction shall be compatible with temperature, humidity, barometric pressure, and voltage fluctuations of the machinery room operating environment.

PART 3 – EXECUTION

3.1 examination

DN. Examine roughing-in for concrete equipment bases, anchor-bolt sizes and locations, piping and electrical to verify actual locations and sizes before chiller installation and other conditions that might affect chiller performance, maintenance, and operation. Equipment locations shown on drawings are approximate. Determine exact locations before proceeding with installation.

3.2 Equipment INSTALLATION

DO. Install chiller on concrete base with isolation pads or vibration isolators.

Concrete base is specified in Section 03 30 00, CAST-IN-PLACE CONCRETE

Vibration isolator types and installation requirements are specified in Section 23 05 41, NOISE and VIBRATION CONTROL FOR HVAC PIPING and EQUIPMENT

Anchor chiller to concrete base according to manufacturer’s written instructions and for seismic restraint on vibration isolators.

Charge the chiller with refrigerant, if not factory charged.

Install accessories and any other equipment furnished loose by the manufacturer, including remote starter, remote control panel, and remote flow switches, according to the manufacturer written instructions and electrical requirements.

Chillers shall be installed in a manner as to provide easy access for tube pull and removal of compressor and motors etc.

DP. Install refrigerant monitoring and safety equipment in accordance with ASHRAE Standard 15.

DQ. Install thermometers and gages as recommended by the manufacturer and/or as shown on drawings.

DR. Piping Connections:

Make piping connections to the chiller for chilled water, condenser water, and and other connections as necessary for proper operation and maintenance of the equipment.

Make equipment connections with flanges and couplings for easy removal and replacement of equipment from the equipment room.

Extend vent piping from the relief valve and purge system to the outside.

3.3 STARTUP AND TESTING

DS. Engage manufacturer's factory-trained representative to perform startup and testing service.

DT. Inspect, equipment installation, including field-assembled components, and piping and electrical connections.

DU. After complete installation startup checks, according to the manufacturers written instructions, do the following to demonstrate to the VA that the equipment operate and perform as intended.

Check refrigerant charge is sufficient and chiller has been tested for refrigerant leak.

Check bearing lubrication and oil levels.

Verify proper motor rotation.

Verify pumps associated with chillers are installed and operational.

Verify thermometers and gages are installed.

Verify purge system, if installed, is functional and relief piping is routed outdoor.

Operate chiller for run-in-period in accordance with the manufacturer’s instruction and observe its performance.

Check and record refrigerant pressure, water flow, water temperature, and power consumption of the chiller.

Test and adjust all controls and safeties. Replace or correct all malfunctioning controls, safeties and equipment as soon as possible to avoid any delay in the use of the equipment.

Prepare a written report outlining the results of tests and inspections, and submit it to the VA.

DV. Engage manufacturer’s certified factory trained representative to provide training for 16 hours for the VA maintenance and operational personnel to adjust, operate and maintain equipment.

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