SpecsBidItem6.pdf

4-Ton Condensing Unit

Lennox Model # TSAO48-G, or equal

Part 1: General

1.01 Summary

A. Section includes design, performance criteria, refrigerants and all preparation requirements for installation by MWRA staff for air cooled split condensing units.

1.02 References

A. ARI-365 Commercial and Industrial Unitary Air Cooled Condensing Units B. ANSI/ASHRAE 15 Safety Standard for Refrigerated Systems.

1.03 Submittals

A. Submit shop drawings and product data in accordance with the specifications.

B. Submittals shall include the following:

1) Dimensioned drawings with required clearances and location of all field connections;

2) Summary of all auxiliary utility requirements such as electricity, water, compressed air, etc. Summary shall indicate quality and quantity of each required utility.

1.04 Qualifications

A. Qualifications: Equipment manufacturer must specialize in the manufacture of the type of products specified and have five (5) years experience with similar equipment and refrigerant offered;

B. Regulatory requirements: Comply with all applicable codes and standards;

C. Manufacturer must be ISO Registered.

1.05 Delivery and Handling

A. Condensing units shall be delivered to the job site assembled and charged with a holding charge of dry nitrogen;

B. Comply with the manufacturer’s instructions for rigging and handling equipment.

1.06 Warranty

A. The warranty offered by the manufacturer of the refrigeration equipment shall be a standard 12 month period from installation, or 18-months from shipment, whichever occurs first. The warranty shall provide for repair or replacement due to material and workmanship that proves defective within the above named period, excluding refrigerant.

1.07 Maintenance

A. Include instructions for installation, maintenance and service;

B. Maintenance of the units shall be the responsibility of the Massachusetts Water

Resources and performed in strict accordance with the manufacturer’s instructions.

Part 2: Products

2.01 Acceptable Manufacturers

A. McQuay International B. Trane C. Approved equal

2.02 Unit Description

A. Provide and install as shown on the plans factory-assembled, air cooled scroll compressor, R410A condensing units in the size and quantity specified. Each unit shall consist of hermetic scroll compressor air cooled condenser section;

B. The complete unit shall be UL listed.

2.03 Design Requirements

A. General: Provide a complete condensing unit as specified herein and as shown on the drawings. The unit shall be in accordance with the standards referenced in Section 1.02 and any local codes in effect;

B. Performance: Refer to the schedule of performance on the drawings.

2.04 Condensing Section (Scroll)

A. Air Cooled Condenser

1) Exterior panels shall be constructed of pre-coated steel with a 1,000 – hour ASTM B117 salt spray test;

2) The condensing section shall be open on the sides and bottom to provide access and to allow airflow through the coils. Condenser coils shall be constructed with 3/8” copper tubing mechanically bonded to aluminum fins for maximum heat transfer.

All copper connections and condenser coils shall be electro-fin™ coated and factory leak tested with high-pressure air under water;

3) Condenser fans shall be direct- drive, propeller-type designed for low tip speed, vertical air discharge and include service guards. Fan blades shall be constructed of steel and riveted to a steel centered hub. Condenser fan motor shall be direct drive, single phase permanently lubricated “PSC” motors with inherent thermal overload;

4) Unit shall have standard pressure controls that cycle the condenser fan motors to maintain condensing pressures for operation down to 0° F ambient.

B. Scroll Compressors

1) Unit shall have heavy-duty Copeland scroll compressors;

2) Compressors shall be equipped with thermal overload protection;

3) Compressors shall be isolated with resilient rubber isolators to decrease noise transmission;

4) Compressor circuit shall be compete with low pressure control, liquid line shut off valve and manual reset high pressure safety switch.

C. Refrigerant Circuit: Capped connections shall be external to the unit providing for field connection of refrigerant piping.

D. Unit shall have a liquid line and suction line service valve.

2.05 Controls

A. Unit shall be equipped with a 24-V terminal strip for field supplied and installed controls.

2.06 Electrical

A. All wiring shall comply with UL requirements. The unit shall be provided with a factory wired weatherproof control panel. Unit shall have a single point power terminal block for main power connection. A terminal board shall be provided for low voltage control wiring;

B. Unit shall be equipped with low voltage transformers and motor starters.

Part 3: Execution

3.01 Installation

A. Installation by MWRA staff in strict accordance with manufacturer’s requirements, shop drawings and contract documents;

B. Adjust and level unit in alignment on supports;

C. Coordinate electrical installation with electrical contractor;

D. Coordinate controls with control contractor.

3.02 Start-Up

A. Provide installation oversight as required;

B. Provide testing and starting of machine, and instruction to owner in its proper operation and maintenance.