Filter
Top Products
36
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--stagescrollcompressorfor heating and coolingduty
and optional electric heating. Unitshall 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 fo r safety requirements.
E. Roof curb shall be desig ned 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
theunit enclosureshallbeall factory wiring,piping,controls, re-
frigerantcharge(R--410A),and special featuresrequired prior to
field s tart--up.
B. Unit Cabinet:
1. Unitcabinet 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 unitshall be constructed on arustproof unit base thathas
an externally trapped, integrated sloped drain pan.
4. Indoor fan compartment top surface shall be insulated with a
minimum 1/2--in. ( 13 mm) th ick, flexible fiberglass
insulation,coated on the air side and retained by adhesiveand
mechanical means. The indoorwall sections will be insulated
with a foil--faced insulation capable of being wiped clean.
Aluminum foil--faced fiber glass 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.
Itshall 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. O perating 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:
Allunit power wiring shallenterunitcabinetata singlelocation.
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 bearingsand
inherent automatic--reset thermal overload protection.
3. Outdoor fan motor shall be totally enclosed.
L. Grille
1. Louvered Grille:
Louvered g rille shall be standard on all units.