Carrier 50XT manual Guide Specifications

GUIDE SPECIFICATIONS

SINGLE-PACKAGED HEAT PUMP UNITS

CONSTANT VOLUME APPLICATION

HVAC GUIDE SPECIFICATIONS

SIZE RANGE: 2 TO 5 TONS, NOMINAL (COOLING)

MODEL NUMBER: 50XT

PART I - GENERAL

SYSTEM DESCRIPTION

Outdoor rooftop or ground mounted heat pump unit utilizing a hermetic, 2-stage scroll compressor for heating and cooling duty and optional electric heating. Unit shall discharge supply air ver- tically or horizontally as shown on contract drawings. Outdoor fan/coil section shall have a draw-thru design with vertical dis- charge for minimum sound levels.

QUALITY ASSURANCE

A. Unit shall be rated in accordance with ARI Standards 210/240 and 270.

B. Unit shall be designed in accordance with UL Standard 1995.

C.Unit shall be manufactured in a facility registered to ISO 9001 manufacturing quality standard

D.Unit shall be UL listed and c-UL certified as a total package for safety requirements.

E.Roof curb shall be designed to conform to NRCA Standards.

F.Insulation and adhesives shall meet NFPA 90A requirements for flame spread and smoke generation.

G.Cabinet insulation shall meet ASHRAE Standard 62P.

DELIVERY, STORAGE, AND HANDLING

Unit shall be stored and handled per manufacturer’s recommen- dations.

PART 2- PRODUCTS

EQUIPMENT

A. General:

Factory-assembled, single-piece, heat pump. Contained within the unit enclosure shall be all factory wiring, piping, controls, re- frigerant charge (R-410A), and special features required prior to field start-up.

B.Unit Cabinet:

1.Unit cabinet shall be constructed of phosphated, zinc-coated, prepainted steel capable of withstanding 500 hrs of salt spray.

2.Normal service shall be through a single removable cabinet panel.

3.The unit shall be constructed on a rust proof unit base that has an externally trapped, integrated sloped drain pan.

4.Indoor fan compartment top surface shall be insulated with a

minimum 1/2-in. (13 mm) thick, flexible fiberglass insulation, coated on the air side and retained by adhesive and mechanical means. The indoor wall sections will be insulated with a foil-faced insulation capable of being wiped clean. Aluminum foil-faced fiberglass insulation shall be used in the entire indoor air cavity section.

5.Unit shall have a field-supplied condensate trap.

C.Fans:

1.The indoor fan shall be variable-speed motor and control, as shown on equipment drawings.

2.Fan wheel shall be made from steel, be double-inlet type. It shall have forward-curved blades with a corrosion-resistant finish and shall be dynamically balanced.

3.Outdoor fan shall be of the direct-driven propeller type with aluminum blades, riveted to corrosion-resistant steel spiders. It shall be dynamically balanced, and discharge air vertically.

D.Compressor:

1.Fully hermetic, 2-stage scroll compressors with factory-installed vibration isolation.

2.Scroll compressors shall be standard on all units.

3.Compressor Protection:

Defrost control shall protect compressor by preventing “short cycling.”

E.Coils:

1.Indoor and outdoor coils shall have aluminum plate fins mechanically bonded to seamless copper tubes with all joints brazed.

2.Tube sheet openings shall be bellied to prevent tube wear.

F.Refrigerant Metering Device:

Refrigerant metering device shall be of the single body, fixed orifice feed type (outdoor) and TXV (indoor).

G.Filters:

Filter section shall consist of field-installed, throw-away, 1-in. thick fiberglass filters of commercially available sizes.

H.Controls and Safeties:

1.Unit controls shall be complete with self-contained low voltage control circuit.

2.Units shall incorporate an internal compressor protector that provides reset capability.

3.Unit shall provide high- and low-/loss-of-charge pressure safety protection.

I.Operating Characteristics:

1.Unit shall be capable of starting and running at 125°F (51.6_C) ambient outdoor temperature, exceeding maximum load criteria of ARI Standard 240.

2.Compressor shall be capable of operation down to 55°F (12.7_C) ambient outdoor temperature in cooling and -10°F in heating.

3.Unit shall be capable of low-ambient cooling (below 55_F (12.7_C) ambient outdoor temperature) with low-ambient cooling enabled on the UI.

J.Electrical Requirements:

All unit power wiring shall enter unit cabinet at a single location.

K.Motors:

1.Compressor motors shall be of the refrigerant-cooled type with line-break thermal and current overload protection.

2.All fan motors shall have permanently lubricated bearings and inherent automatic-reset thermal overload protection.

3.Outdoor fan motor shall be totally enclosed.

L.Grille

1.Louvered Grille:

Louvered grille shall be standard on all units.

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