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Guide specifications, Guide specifications -31 – Carrier EVERGREEN 23XRV User Manual

Page 24

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Variable Speed Screw Chiller

HVAC Guide Specifications

Size Range:

300 to 550 Tons (1055 to 1934 kW)
Nominal

Carrier Model Number:

23XRV

Part 1 — General
1.01 SYSTEM DESCRIPTION

A. Microprocessor-controlled liquid chiller shall use a

semi-hermetic screw compressor using refrigerant
HFC-134a only. Chiller refrigerant shall not have a
planned phase out date.

B. If a manufacturer proposes a liquid chiller using

HCFC-123 refrigerant, which has a planned phase
out date, then the manufacturer shall include in the
chiller price:

1. A vapor activated alarm system consisting of all

alarms, sensors, safeties, and ventilation equip-
ment as required by ANSI/ASHRAE Standard
15 Safety Code for Mechanical Refrigeration
(latest edition) with the quotation. System shall
be capable of responding to HCFC-123 levels
of 10 ppm Allowable Exposure Limit (AEL).

2. A free-standing refrigerant storage tank and

pumpout unit shall be provided. The storage
vessels shall be designed per ASME Section VIII
Division 1 code with 300 psig (2068 kPa)
design pressure. Double relief valves per ANSI/
ASHRAE 15, latest edition, shall be provided.
The tank shall include a liquid level gage and
pressure gage. The pumpout unit shall use a
semi-hermetic reciprocating compressor with
water cooled condenser. Condenser water pip-
ing, 3-phase motor power, and 115-volt control
power shall be installed at the jobsite by the
installing contractor.

3. Zero emission purge unit capable of operating

even when the chiller is not operating.

4. Back-up relief valve to rupture disk.
5. Factory-installed chiller pressurizing system to

prevent leakage of noncondensables into the
chiller during shutdown periods.

6. Plant room ventilation.
7. Removal and disposal of refrigerant at the end

of the phase out period.

8. Chillers utilizing a purge unit shall include in the

machine price the costs to perform the follow-
ing regular maintenance procedures:
a. Weekly: Check refrigerant charge.
b. Quarterly: Charge purge unit dehydrator at

least quarterly, more often if necessary.
Clean foul gas strainer. Perform chemical
analysis of oil.

c. Annually: Clean and inspect all valves. Drain

and flush purge shell. Clean orifices.

1.02 QUALITY ASSURANCE

A. Chiller performance shall be rated in accordance

with AHRI Standard 550/590, latest edition.

B. Equipment and installation shall be in compliance

with ANSI/ASHRAE 15 (latest edition).

C. Cooler and condenser refrigerant side shall include

ASME “U” stamp and nameplate certifying compli-
ance with ASME Section VIII, Division 1 code for
unfired pressure vessels.

D. A manufacturer’s data report is required to verify

pressure vessel construction adherence to ASME
vessel construction requirements. Form U-1 as
required per ASME code rules is to be furnished
to the owner. The U-1 Form must be signed by a
qualified inspector, holding a National Board
Commission, certifying that construction conforms
to the latest ASME Code Section VIII, Div. 1 for
pressure vessels. The ASME symbol “U” must also
be stamped on the heat exchanger. Vessels specifi-
cally exempted from the scope of the code must
come with material, test, and construction methods
certification and detailed documents similar to
ASME U-1; further, these must be signed by an offi-
cer of the company.

E. Chiller shall be designed and constructed to meet

UL and UL of Canada requirements and have labels
appropriately affixed.

F. Unit shall be manufactured in a facility registered to

ISO 9001:2000 Manufacturing Quality Standard.

G. Each compressor assembly shall undergo a mechan-

ical run-in test to verify vibration levels, oil pressures,
and temperatures are within acceptable limits. Each
compressor assembly shall be proof tested at a mini-
mum 204 psig (1407 kPa) and leak tested at
185 psig (1276 kPa) with a tracer gas mixture.

H. Entire chiller assembly shall be proof tested at

204 psig (1407 kPa) and leak tested at 185 psig
(1276 kPa) with a tracer gas mixture on the refriger-
ant side. The leak test shall not allow any leaks
greater than 0.5 oz per year of refrigerant. The
water side of each heat exchanger shall be hydro-
statically tested at 1.3 times rated working pressure.

I. Prior to shipment, the chiller automated controls

test shall be executed to check for proper wiring and
ensure correct controls operation.

J. Chillers shall have factory-mounted, factory-wired

and factory-tested unit-mounted variable frequency
drive (VFD). Proper VFD operation shall be con-
firmed prior to shipment.

1.03 DELIVERY, STORAGE AND HANDLING

A. Unit shall be stored and handled in accordance with

manufacturer’s instructions.

B. Unit shall be shipped with all refrigerant piping and

control wiring factory-installed.

C. Unit shall be shipped charged with oil and full

charge of refrigerant HFC-134a or a nitrogen hold-
ing charge as specified on the equipment schedule.

Guide specifications