SECTION 236400 - PACKAGED WATER CHILLERS



This master should be used by designers working on Port of Portland construction projects and by designers working for PDX tenants (“Tenants”). Usage notes highlight a few specific editing choices, however the entire section should be evaluated and edited to fit specific project needs.

SECTION 236400 - PACKAGED WATER CHILLERS

GENERAL

1. DESCRIPTION

A. This section describes air-cooled water chillers.

2. RELATED WORK SPECIFIED ELSEWHERE

A. Section 230500, Common Work Results for HVAC

B. Section 230519, Meters and Gauges for HVAC Piping

C. Section 230520, Piping Specialties for HVAC Piping

D. Section 230523, General Duty Valves for HVAC Piping

E. Section 230529, Hangers and Supports for HVAC Piping and Equipment

F. Section 230545, Seismic Restraints for HVAC Piping and Equipment

G. Section 230548, Vibration and Seismic Controls for HVAC Piping and Equipment

H. Section 230553, Identification for HVAC Piping and Equipment

I. Section 230593, Testing, Adjusting, and Balancing

J. Section 230900, Instrumentation and Controls for HVAC

K. Section 232000, HVAC Piping

L. Section 232220, HVAC Pumps

3. REFERENCES

A. ANSI: American National Standards Institute

1. ANSI B15: Safety Code for Mechanical Refrigeration

B. ARI: Air-Conditioning and Refrigeration Institute

1. ARI 550: Performance Rating of Water Chilling Packages Using the Vapor Compression Cycle

C. ASME: American Society of Mechanical Engineers

1. ASME BPVC: Boiler and Pressure Vessel Code for Unfired Vessels

4. SUBMITTALS

A. For systems, equipment, and components specified herein, submit product/material data; certified shop drawings; operation and maintenance data; as-constructed data; installation, start up, and testing manuals; operation and maintenance manuals; and as-constructed drawings.

1. Shop Drawings: Include complete details of construction.

2. Product Data: Include performance data.

3. Provide part load operating characteristics and application part load value calculation (APLV) in accordance with ARI 550.

Use only if Commissioning Section 019100 is included in the project manual.

B. For systems, equipment, and components specified herein, submit commissioning plans and schedules; checkout, startup, operational, functional and final acceptance test plans, procedures, checklists, and reports; systems manuals; and operation and maintenance training plans.

PRODUCTS

1. AIR-COOLED WATER CHILLER

A. Acceptable Manufacturers: Carrier, Trane, York, McQuay, or pre-bid approved equal.

B. Description: Complete packaged reciprocating or rotary air-cooled water chiller, consisting of compressors, air-cooled condensers, refrigerant piping and specialties, and controls all contained on a common frame. Provide a one-piece integral unit. Unit shall be fully charged with refrigerant at factory. Construct in accordance with ANSI B15 Safety Code for Mechanical Refrigeration. Wiring and piping shall be contained within the unit enclosure. All electrical components shall be mounted in a rain-tight enclosure. The exterior sheet metal shall be galvanized steel, with an electrostatically applied baked enamel finish.

C. Compressor: Semi-hermetic reciprocating compressor with multi-step capacity control or rotary compressor with slide valve and discharge muffler. Positive displacement oil pump. Suction and discharge service valve. Electric actuated, cylinder head unloading or slide valve. Removable crankcase opening with crankcase heater in crankcase well.

D. Motor: Continuous duty induction type to match compressor torque curves, cooled by full flow of suction gas and suitable for voltage fluctuation of (10 percent of nameplate voltage. Provide solid state sensor in each motor winding to protect against excess winding temperatures.

E. Evaporator: Shell and tube design with seamless copper tubes expanded into tube sheets and removable heads for mechanical tube cleaning. Test and stamp units in accordance with ASME BPVC: Boiler and Pressure Vessel Code for Unfired Vessels, for refrigerant side working pressure of 225 psig and water side working pressure of 150 psig. Provide water manifold package for single supply and return water connections.

F. Air-Cooled Condensers: Unit circuited to provide subcooling. Condensers constructed of 1/2-inch OD seamless copper tubes with mechanically bonded aluminum fins, leak tested at 150 psig, pressure tested at 450 psig.

G. Condenser Fans and Motors: Provide direct-drive, propeller type condenser fans, with steel wire safety guards and 3-phase, permanently lubricated and inherently protected fan motors with corrosion-resistant fan shaft.

H. Head Pressure Control: Provide head pressure control system. Cycled condenser fans by a combination of discharge pressure and ambient temperature to permit operation to 40ºF outdoor ambient temperature.

I. Refrigerant Circuit Accessories: Provide all required refrigeration accessories, including condenser liquid line valves, combination filter-dryers, solenoid liquid stop valves, liquid line sight glasses, expansion valves and discharge valve on compressors.

J. Insulation: Factory insulate evaporator including heads and cold refrigerant piping and condenser including head with 3/4-inch expanded polyvinyl chloride (K = 0.26) over heaters to protect against freezing.

K. Wiring: Field wiring shall consist of dual point electrical connection to chiller and 115V control interlock wiring to pumps and flow switches. Provide terminals.

L. Control Panel: Unit equipped with control panel utilizing 120-volt, single phase power supply from transformer in starter and containing the following microprocessor based accessories and features:

1. Display of evaporator/condenser refrigerant pressures, oil pressure, return/leaving chilled water temperature, return/leaving condenser water temperatures, evaporator/condenser refrigerant temperatures, compressor discharge temperature, oil temperature.

2. Programming of setpoints shall be through keypad and include leaving chilled water temperature, percent current demand, and remote reset temperature range.

3. Safety controls annunciated through alpha-numeric display and include high/low oil pressure, high/low refrigerant pressure, low chilled water temperature, starter faults, low flow through evaporator /condenser, high oil temperature, high compressor discharge temperature, high motor temperature.

4. Battery back-up for control panel with circuit protection from high voltage and power surge conditions.

5. Choice of control modes from hand/off/auto.

6. Extra contact to annunciate machine failure to remote area and extra contact for safety shutdown from external source.

7. Pilot relays to start chilled water pumps.

8. Time limit control to limit starts to one in 30 minutes.

M. Capacity Control: Electronic thermostat and controller to modulate capacity of machine to maintain constant ((0.5ºF) chilled water supply temperature. Chilled water temperature setpoint shall be remotely adjustable from building control system. Coordinate requirements with Section 230900, Instrumentation and Controls for HVAC. Machine shall modulate to within 20 percent capacity without using hot gas bypass in accordance with ARI 550 requirements.

N. Starter:

1. Provide unit-mounted starter cabinet with combination starter and circuit breakers.

2. Provide protection devices including 3-leg overload protection high temperature safety protection with indicating light and reset button, over and under voltage protection.

3. Provide indicator lights on starter panel including control power on, chiller start, chiller run, overload current.

O. Refrigerants: Use R-410A, R-407, R-134a, or pre-bid approved equal. Chillers using other refrigerants will not be accepted unless prior approval received. No HCFC’s are acceptable.

P. Performance: Certify performance in accordance with ARI 550. Performance shall be based on 0.00025 fouling factors for evaporator.

EXECUTION

1. INSTALLATION

A. General: Install in accordance with the manufacturer’s instructions.

B. Prior to installation, coordinate chiller control interface and verify that intended installation (controls, piping, etc.) complies with the manufacturer’s recommendations.

C. Pipe Connections: Arrange connections to chiller to prevent pipe weight or stresses from being transferred to chiller and to provide easy access for tube cleaning.

Choose one of the following two articles. Use Commissioning if Section 019100 is included in the project manual; otherwise use Testing.

2. COMMISSIONING

A. Commission systems, equipment, and components specified herein.

1. Comply with the manufacturer’s instructions for startup.

2. Provide startup under the direct supervision of the manufacturer’s representative with factory trained personnel.

3. Except where initial chiller operation clearly shows the performance meets or exceeds the requirements, field test chillers to show compliance. Tests shall be performed by the manufacturer’s representative in the presence of the Port.

3. TESTING

A. Check out, start up, and test systems, equipment, and components specified herein.

1. Comply with the manufacturer’s instructions for startup.

2. Provide startup under the direct supervision of the manufacturer’s representative with factory trained personnel.

3. Except where initial chiller operation clearly shows the performance meets or exceeds the requirements, field test chillers to show compliance. Tests shall be performed by the manufacturer’s representative in the presence of the Port.

END OF SECTION 236400

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download