Cooling System Upgrade Rotary - Screw Section 15620 Ralph Pickard

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Cooling System Upgrade Rotary - Screw Section 15620 Ralph Pickard Powered By Docstoc
					Cooling System Upgrade                   Rotary - Screw                         Section 15620
Ralph Pickard Bell Library               Water Chillers                         Page 1
Mount Allison University                                                        February 2010
Sackville, NB                                                                   Quotation # LIBR-10-01


PART 1 - GENERAL

1.1 References               .1   CSA B52-05 Mechanical Refrigeration Code.

                             .2   ASHRAE 90-1.

1.2 Submittals               .1   Submit shop drawings in accordance with Section 01340 – Shop
                                  Drawings, Product Data and Mock-ups.

                             .2   Submit drawings indicating components, assembly, dimensions,
                                  weights and loadings, required clearances, and location and size of
                                  field connections. Indicate equipment, piping and connections, valves
                                  and strainers.

                             .3   Submit product data indicating rated capacities, weights, specialties
                                  and accessories, electrical requirements and wiring diagrams.

                             .4   Submit manufacturer's installation instructions.

                             .5   Submit performance data on full and part load operating loads.

1.3 Operation and
Maintenance Data             .1   Provide operation and maintenance data for incorporation into manual
                                  specified in Section 01730 – Operation and Maintenance Manuals.

                             .2   Include start-up instructions, operation data, maintenance data,
                                  controls, and accessories. Include trouble-shooting guide.

1.4 Warranty                 .1   Provide a full parts and labour warranty for one year from start-up or
                                  18 months from shipment, whichever occurs first.

PART 2 – PRODUCTS

2.1 Summary                  .1   The contractor shall furnish and start-up and commission a rotary
                                  screw water chiller as herein specified. The units shall be supplied in
                                  accordance with this specification and in accordance with ARI
                                  Standard 550/590-2003. The unit shall be ARI certified as applicable,
                                  ASHRAE 90-1 and C/UL listed. Unit to be registered with N.B.
                                  Safety Code Services if required.

                             .2   Approved manufacturers:
                                  .1     Trane Model RTWD 150 or equal to operate on 208/3/60 for
                                  operation on R134a.

                             .3   Chiller to be delivered with oil and refrigerant charged separate to be
Cooling System Upgrade                      Rotary - Screw                          Section 15620
Ralph Pickard Bell Library                  Water Chillers                          Page 2
Mount Allison University                                                            February 2010
Sackville, NB                                                                       Quotation # LIBR-10-01


                                    installed at time of oil startup by unit supplier.

2.2 Compressor
and Motor      .1            Construct chiller using semi-hermetic helical rotary screw compressors with
                                    independent circuits

                             .2     Provide crankcase heater to evaporate refrigerant returning to
                                    crankcase during shut down. Energize heater when compressor is not
                                    operating.

                             .3     Provide each compressor with isolation valves.

2.3 Evaporator               .1     The evaporator shall be built in accordance with ANSI/ASHRAE 15-
                                    Safety Code for Mechanical Refrigeration. Design, test, and stamp
                                    evaporator refrigerant side for 200 psig (1379 kPa) working pressure
                                    in accordance with ANSI/ASME SEC 8.

                             .2     Evaporator tubes shall be copper, internally enhanced and externally
                                    finned to achieve maximum efficiency. The nominal tube wall
                                    thickness shall be 0.025 inches.

                             .3     Water boxes shall be designed for 150 psig maximum waterside
                                    working pressure and shall be flanged and gasketed for easy removal
                                    and access to the tubes. The water boxes shall have grooved-type
                                    water connections for easy field chilled water and condenser water
                                    connections and have proper orientation as referenced in the scheduled
                                    drawings.

                             .4     Units with multi-stage compressors shall incorporate an interstage
                                    flash vessel economizer in the refrigerant cycle.

                             .5     Factory insulation will be 3/4" insulation Armaflex II or equal
                                    (k=0.28) and cover the evaporator, water boxes and motor housing.
                                    Factory installed foam insulation will be used on the suction line,
                                    liquid level sensor and oil return system assembly.

2.3 Performance              .1     Kw/ton full load less than .65. NPLV (Kw/ton) to be equal to or less
                                    than .58.

                             .2     Unit to provide 150 tons capacity when operation at standard ARI
                                    conditions.

2.4 Electrical               .1     Unit to be supplied with Wye – Delta closed transition starter in
                                    NEMA 1 enclosure. Starter to have 3 phase overload protection.
                                    Starter to be factory mounted and wired.
Cooling System Upgrade                   Rotary - Screw                         Section 15620
Ralph Pickard Bell Library               Water Chillers                         Page 3
Mount Allison University                                                        February 2010
Sackville, NB                                                                   Quotation # LIBR-10-01


2.5 Water Cooled
Condenser                    .1   The water-cooled condenser shall be built in accordance with
                                  ANSI/ASHRAE 15 Safety Code for Mechanical Refrigeration.
                                  Design, test, and stamp condenser refrigerant side for 300 psig (2068
                                  kPa) working pressure in accordance with ANSI/ASME SEC 8.

                             .2   Water-cooled condenser tubes shall be copper, internally enhanced and
                                  externally finned to achieve maximum efficiency. The nominal tube
                                  wall thickness shall be 0.028 inches.

                             .3   Water boxes shall be designed for 150 psig maximum waterside
                                  working pressure and shall be flanged and gasketed for easy removal
                                  and access to the tubes. The water boxes shall have grooved-type
                                  water connections for easy field chilled water and condenser water
                                  connections and have proper orientation as referenced in the scheduled
                                  drawings.

2.6 Refrigerant
Circuit                      .1   All units shall have 2 independent refrigerant circuits, each with a
                                  separate single compressor. If manifolded compressors are provided
                                  on a circuit, then individual compressor warranties must be provided
                                  for each compressor on the circuit.

                             .2   Provide for each refrigerant circuit
                                  .1     Suction service valve
                                  .2     Discharge service valve
                                  .3     Liquid line shutoff valve

2.7 Controls                 .1   The chiller(s) shall be controlled by a microprocessor-based,
                                  proportional and integral controller to show water and refrigerant
                                  temperatures, refrigerant pressures and diagnostics. A dedicated
                                  chiller control panel with a non-coded display is to be supplied with
                                  each chiller by the chiller manufacturer. The controller shall provide
                                  chiller capacity control in response to the leaving chilled water
                                  temperature.

                             .2   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:
                                  .1      High pressure limit that is set 10% lower than factory pressure
                                  switch that will automatically unload the compressor to help prevent a
                                  high pressure condenser control trip. One switch is required for each
                                  compressor and indicating light shall also be provided.
                                  .2      Current limit setpoint that is set to 120% of compressor RLA
                                  that will automatically unload the compressor to help prevent an
Cooling System Upgrade                    Rotary - Screw                        Section 15620
Ralph Pickard Bell Library                Water Chillers                        Page 4
Mount Allison University                                                        February 2010
Sackville, NB                                                                   Quotation # LIBR-10-01


                                   overcurrent trip. One protector is required for each compressor and
                                   indicating light shall also be provided.
                                   .3      Low refrigerant temperature limit that will automatically
                                   unload the compressor to help prevent a low evaporator temperature
                                   trip.

                             .3    The chiller shall provide the following points for system control and
                                   monitoring.


PART 3 – EXECUTION

3.1 Manufacturer’s
Field Services               .1    OEM Startup is performed by factory trained and authorized servicing
                                   technicians confirming equipment has been correctly installed and
                                   passes specification checklist prior to equipment becoming operational
                                   and covered under OEM warranty.
                                   .1      Included OEM Factory Startup:
                                           a.     Rotary Screw/Scroll Chillers

                             .2    The manufacturer shall furnish complete submittal wiring diagrams of
                                   the package unit as applicable for field maintenance and service.



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