Carrier 50XP - Manual (Page 23)

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GUIDE SPECIFICATIONS
Packaged Electric Cooling Unit
Constant Volume Application
HVAC Guide Specifications
Size Range: 2 to 5 Tons, Nominal Cooling
Model Number: 50XP
Part 1 — General
SYSTEM DESCRIPTION
Outdoor rooftop mounted or ground mounted, electric cooling
unit utilizing a hermetic compressor for cooling duty and
optional electric heating. Unit shall discharge supply air
vertically or horizontally as shown on contract drawings.
Condenser fan/coil section shall have a draw--thru design with
vertical discharge 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
recommendations.
Part 2 — Products
EQUIPMENT
A. General:
Factory--assembled, single--piece, cooling unit. Contained
within the enclosure shall be all factory wiring, piping,
controls, refrigerant charge with R--410A refrigerant, and
special features required prior to field start--up.
B. Unit Cabinet:
1. Unit cabinet shall be constructed of phosphated,
zinc--coated, pre--painted steel capable of with--standing 500
hours in 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. Evaporator 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 evaporator wall sections will be
insulated with a minimum semi--rigid foil--faced board ca-
pable 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 evaporator fan shall be direct--drive variable speed
motor and control, as shown on equipment drawings.
2. Fan wheel shall be made from steel, be double--inlet type
with forward curved blades with corrosion resistant finish.
Fan wheel shall be dynamically balanced.
3. Condenser fan shall be direct drive propeller type with alu-
minum blades riveted to corrosion resistant steel spiders, be
dynamically balanced, and discharge air vertically.
D. Compressor:
1. Fully hermetic compressors with factory--installed vibration
isolation.
2. Scroll compressors shall be standard on all units.
E. Coils:
Evaporator and condenser coils shall have aluminum plate fins
mechanically bonded to seamless copper tubes with all joints
brazed. (Copper/copper and vinyl--coated construction
available as option). Tube sheet openings shall be belled to
prevent tube wear.
F. Refrigerant Components:
Refrigerant expansion device shall be of the TXV
(thermostatic expansion valve) type.
G. Filters:
Filter section shall consist of field--installed, throwaway, 1--in.
(25 mm) thick fiberglass filters of commercially available
sizes.
H. Controls and Safeties:
1. Unit controls shall be complete with a 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_C) ambient outdoor temperature,exceeding maximum
load criteria of ARI Standard 210.
2. Compressor with standard controls shall be capable of op-
eration down to 55_F (13_C) ambient outdoor temperature.
3. Indoor Fan on/off delay profile is selected (for cooling) on
the Easy Select board.
J. Electrical Requirements:
All unit power wiring shall enter the 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. Condenser fan motor shall be totally enclosed.
L. Grille:
1. Louvered Grille:
Louvered grille shall be standard on all units.
50X
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