36C26118B0402-003.doc

04-11

SECTION 23 64 00

PACKAGED WATER CHILLERS

PART 1 ‑ GENERAL

1.1 DESCRIPTION

A. Centrifugal water-cooled chillers, complete with accessories.

1.2 RELATED WORK

A.

Section 00 72 00, GENERAL CONDITIONS.

B.

Section 01 00 00, GENERAL REQUIREMENTS.

1.3 Definition

A.

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.

B.

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

C.

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

D.

FTT-10: Echelon Transmitter-Free Topology Transceiver.

1.4 QUALITY ASSURANCE

A.

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

B.

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

C.

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

D.

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

1.5 Applicable publications

A.

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.

Equipment Space

B.

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

ANSI/ASHRASE-15-2007

Safety Standard for Mechanical Refrigeration Systems

C.

National Fire Protection Association (NFPA):

70-2008 National Electrical Code

D.

Underwriters Laboratories, Inc. (UL):

1995-2005 Heating and Cooling Equipment

1.6 SUBMITTALS

A.

Submit in accordance with Specification Section 01 33 23, PRODUCT DATA.

B.

Manufacturer's Literature and Data.

1.

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.

d.

Refrigerant f.

Accessories.

g.

Installation instructions.

h.

Start up procedures.

i.

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

j.

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

C.

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

D.

Run test report for all chillers.

PART 2 ‑ PRODUCTS

A.

Performance: Provide the capacity as shown on the drawings. Part load and full load efficiency ratings of the chiller shall not exceed those shown on the drawings. //If chillers are required to operate at less than 25 percent of full unit rated capacity, specify provision for hot gas by-pass, to operate the unit stable at any stage of capacity reduction.// B.

Capacity of a single water-cooled chiller shall not exceed 1,250 Tons (Standard AHRI Conditions).

C.

Controls: Chiller shall be furnished with unit mounted, stand-alone, microprocessor-based controls in // NEMA 1 // NEMA 12 // enclosure, hinged and lockable, factory wired with a single point power connection and separate control circuit. The control panel provide chiller operation, including monitoring of sensors and actuators, and shall be furnished with light emitting diodes or liquid-crystal display keypad.

1.

Following functions shall display as a minimum:

a.

Date and Time.

b.

Outdoor air temperature.

c.

Operating set point temperature and pressure.

d.

Operating hours.

e.

Operating or alarm status.

f.

Chilled water temperature-entering and leaving.

g.

Condenser water temperature-entering and leaving.

h.

Refrigerant pressure-condenser and evaporator.

i.

Low oil pump pressure.

j.

High oil supply pressure.

k.

Chiller diagnostic codes.

l.

Current limit set point.

m.

Number of compressor starts.

n.

Purge suction temperature, if refrigerant HCFC-123 is used.

o.

Purge elapsed time, if refrigerant HCFC-123 is used.

2.

Control Functions:

a.

Manual or automatic startup and shutdown time schedule.

b.

Control set points for entering and leaving chilled temperatures.

c.

Condenser water temperature.

d.

Current/demand limit.

e.

Motor load limit.

3.

Safety Controls: Following conditions shall shut down the chiller and require manual reset to start:

a.

High condenser pressure.

b.

High oil temperature.

c.

High or low oil pressure.

d.

Loss of flow-condenser or chilled water.

e.

Low chilled water temperature.

f.

Low evaporator refrigerant temperature.

g.

Sensor malfunctions.

h.

Power fault.

i.

Extended compressor surge.

j.

Communication loss between the chiller and its control panel. A signal must be transmitted to Energy Control Center, if provided, for this communication loss and for any abnormal.

4.

The chiller control panel shall provide a relay output to initiate system changeover to free cooling. This relay shall be energized upon initiation of free cooling at the chiller control panel.

5.

Leaving chilled water temperature reset, where specified in the control sequence, shall be based on return water temperature.

6.

Chillers shall be pre-wired to terminal strips for interlocked to other equipment.

7.

Provide contacts for remote start/stop, alarm for abnormal operation or shut down, and for Engineering Control Center (ECC) interface.

8.

Chiller control panel shall reside on the "BACnet network", and provide data using open protocol network variable types and configuration properties, BACnet interworking using ARCNET or MS/TP physical data link layer protocol for communication with building automation control system //.

9.

The chiller control panel shall utilize the following components to automatically take action to prevent unit shutdown due to abnormal operating conditions which will perform as follows.

a.

Low pressure switch that is set at 5 PSIG above the factory low pressure switch that will automatically unload the compressor to help prevent a low evaporator temperature trip. One switch is required for each compressor and indicating light shall also be provided.

b.

In all the above cases, the chiller will continue to run, in an unloaded state and will continue to produce some chilled water in an attempt to meet the cooling load. However, if the chiller reaches the trip-out limits, the chiller controls will take the chiller off line for protection, and a manual reset is required. Once the "near trip" condition is corrected, the chiller will return to normal operation and can then produce full load cooling.

3.3 STARTUP AND TESTING

A.

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

B.

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

C.

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.

1.

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

2.

Check bearing lubrication and oil levels.

3.

Verify proper motor rotation.

4.

Verify pumps associated with chillers are installed and operational.

5.

Verify thermometers and gages are installed.

6.

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

7.

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

8.

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

9.

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.

10.

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

D.

Engage manufacturer’s certified factory trained representative to provide training for // 16 hours // 8 hours // for the VA maintenance and operational personnel to adjust, operate and maintain equipment, including self-contained breathing apparatus.

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