SECTION 15676
AIR COOLED CHILLER
PART 1 - GENERAL
1.01
GENERAL
A.
1.02
SCOPE
A.
1.03
1.04
The Bidding and Contract requirements, Division 1 - General Requirements, section
15010 - General Provisions, and Section 15050 - Basic Materials and Methods, shall
apply to this section.
A complete factory assembled package air-cooled water chiller shall be installed.
QUALITY ASSURANCE
A.
Unit shall be run tested at the factory and start-up and check out shall be done by a
factory certified technician. Pressurized components shall comply with the ASME
code for unfired pressure vessels. Rating and construction shall be in accordance
with ARI Standard 59086, ANSI B9.1 safety code and the National Electrical Code.
B.
Manufacturer shall provide a certification that the equipment has been performance
tested at the factory. Certification shall record the unit capacity in BTU/hour and
kilowatts.
C.
Factory start-up- The manufacturer shall supply complete factory start-up by a
factory approved start-up agent.
D.
Equipment installer shall attend a controls coordination meeting with the
section15900 contractor as described in 15900, 1.03.
SUBMITTALS
A.
Provide shop drawings on this equipment as described in section 15010, 1.04. The
controls coordination meeting described in 15900, 1.03 shall be held before the shop
drawings are submitted.
PART 2 - PRODUCTS
2.01
AIR COOLED CHILLER
The air-cooled chiller shall be of the type and capacity shown in the equipment schedule on
the drawings. The unit shall be manufactured by TRANE. A unit fully equal to that specified
and manufactured by CARRIER or McQUAY is acceptable.
15676-1
11/13
AIR COOLED CHILLER
SECTION 15676
A.
Unit Description - The Air Cooled chiller shall be a factory assembled, piped, wired
and tested unit consisting of a corrosion protected steel casing, an evaporator,
condensers, multiple scroll or screw compressors, control panel, refrigerant piping
and dual refrigeration system all assembled on one base with accessories as
required in this specification or as shown on the drawings. Motor starters shall be
unit mounted. The refrigerant used shall have an ozone depletion potential of less
than .05 and a global warming potential of less than 0.37, (R-134A, R-410A).
B.
Unit Casing - Unit shall be enclosed in a galvanized steel casing, zinc phosphatized,
with an electrostatically applied baked enamel finish, capable of withstanding
Federal Test Method Standard No. 141, Method 6061, 500 hour salt spray test.
C.
Evaporator/Cooler - Shall be shell and tube type with removable heads and shall
have two independent direct-expansion refrigerant circuits. Cooler shall be tested
and stamped in accordance with ASME code for refrigerant side working pressure of
235 psig and a minimum waterside working pressure of 150 psig. Copper tubes
shall be rolled into the tube sheets. Shell shall be covered with 3/4" layer of closedcell foam plastic, vapor insulated.
D.
Condenser
1.
Air cooled condenser coils shall have aluminum fins mechanically bonded to
seamless copper tubes, cleaned, dehydrated, sealed, leak tested at 150 psig
and pressure tested at 450 psig.
2.
Condenser fans shall be propeller type with PVC coated steel wire safety
guards, balanced statically and dynamically, and shall discharge vertically.
3.
Condenser fan motors shall have inherent overcurrent protection.
4.
Provide metal hail guards to protect the condenser coil from damage.
E.
Compressors - Shall be scroll hermetic type with a maximum speed of 3500 rpm, or
rotary screw, serviceable and shall have an automatically reversible oil pump and
operating oil charge. Compressors shall be equipped with suction and discharge
shutoff valves and shall be mounted on individual spring vibration isolators. Each
compressor motor shall be cooled by suction gas passing around the motor windings
and shall be thermally protected with manual restart after thermal or pressure
overload stoppage. Each compressor shall be equipped with an insert type
crankcase heater to control oil dilution during shutdown. Cycles per hour per
compressor shall not exceed six.
F.
Refrigeration Circuit - Each refrigeration circuit shall include: hot gas muffler,
combination moisture indicator and sight glass, replaceable core refrigerant filter
drier, liquid line solenoid valve, expansion valve, suction and discharge pressure
gauges with manual shutoff valves, high side pressure relief device, and charging
valve.
15676-2
11/13
AIR COOLED CHILLER
G.
SECTION 15676
Controls
1.
Unit controls, including microprocessor, shall be factory mounted and wired
in a weatherproof enclosure with hinged access doors for easy access. The
controls shall include automatic lead-lag except where noted, pumpdown at
beginning and end of every circuit cycle, loss-of-charge protection, inherent
low water flow protection, low chilled water temperature safety, low- and
high-suction superheat protection, low oil pressure protection for each circuit,
ground current protection for each compressor, low control voltage to unit,
current limit, field power and control circuit terminal blocks, compressor and
fan motor circuit breakers, ON/OFF switch, replaceable relay board,
individual solid-state compressor protection board, leaving chilled water set
point board, diagnostic digital display module, a microprocessor board and a
temperature reset board. The chiller shall be capable of sending a chill water
pump run request to the building automation system.
2.
Unit control capacity is based upon leaving water temperature and will be
compensated by return water temperature.
3.
Minimum number of capacity control steps shall be as shown in the
equipment schedule.
4.
Provide a definite purpose magnetic contactor for each compressor.
5.
Calibrated circuit breakers shall be factory installed for each compressor,
shall be manual reset and ambient insensitive, and shall open all three
phases should an overload occur on any phase.
6.
Unit primary electrical power supply shall be connected to a single point with
lugs sized for specified conductors.
7.
Control voltage shall be provided by a factory installed integral control
transformer.
8.
Heat tracing for exterior piping shall be provided by a separate 120 volt,
single phase power supply.
9.
Provide a barrel freeze alarm output for connection to the BAS.
H.
Chiller shall be capable of operating at ambient air temperatures down to 0 deg F
without the use of glycol or any other type of antifreeze. Chillers that do not meet
this requirement are not acceptable.
I.
Flow switches- switches for flow conformation shall be provided. Switches shall be
paddle type with stainless steel bellows and paddle. Switches shall be suitable for
outdoor installation.
15676-3
11/13
AIR COOLED CHILLER
SECTION 15676
PART 3 - EXECUTION
3.01
INSTALLATION
A.
Factory Start-up- The manufacturer shall supply complete factory start-up by a
factory approved start-up agent.
B.
Installation - The chiller shall be installed in accordance with the manufacturer's
recommendations.
C.
Install isolation valves on evaporator water inlet and outlet at chiller.
D.
Install thermometers on evaporator water inlet and outlet at chiller.
E.
Isolation - Provide spring isolators as recommended by chiller manufacturer.
F.
Pipe Connections - The machine shall have water boxes or the contractor shall
provide flanged pipe connections in the piping adjacent to the machine to allow
removal of headers for inspection, cleaning or removal of tubes.
G.
Provide an engraved nameplate permanently affixed to the front of the control
cabinet (inside of cabinet for outdoor locations) with the following information.
INSTALLING CONTRACTOR: _______________________________
CONTRACTOR PHONE #
: _______________________________
WARRANTY DATE FROM: __________ TO: ___________________
END OF SECTION
15676-4
11/13