Bryant DURAPAC 551B - Manual (Page 165)

165
GUIDE SPECIFICATIONS — SIZES 155-300
PACKAGED ROOFTOP ELECTRIC COOLING UNIT WITH
ELECTRIC OR GLYCOL HEAT — CONSTANT VOLUME
APPLICATION
HVAC GUIDE SPECIFICATIONS
SIZE RANGE: 13 to 25 TONS, NOMINAL COOLING,
14 to 80 kW (ELECTRIC HEAT)
123,000 to 405,000 BTUH (GLYCOL HEATING)
BRYANT MODEL NUMBERS: 551A, 558F, 559F
PART 1 — GENERAL
1.01 SYSTEM DESCRIPTION
Unit is an outdoor rooftop mounted, electrically controlled
heating and cooling unit utilizing scroll hermetic compres-
sors for cooling duty. Supply air shall be discharged down-
ward or horizontally (with horizontal supply/return curb
adapter assembly), as shown on contract drawings.
Standard unit shall include a manual outdoor-air inlet.
1.02 QUALITY ASSURANCE
A. Unit shall be rated in accordance with ARI Standards 270
and 360 and all units shall be designed in accordance
with UL Standard 1995.
B. Unit shall be designed to conform to ASHRAE 15.
C. Unit shall be ETL and ETL, Canada tested and certified
in accordance with ANSI Z21.47 Standards as a total
package.
D. Roof curb shall be designed to conform to NRCA
Standards.
E. Insulation and adhesive shall meet NFPA 90A require-
ments for flame spread and smoke generation.
F. Unit casing shall be capable of withstanding 500-hour salt
spray exposure per ASTM B117 (scribed specimen).
G. Unit shall be manufactured in a facility registered to
ISO 9002/BS5750, Part 2.
1.03 DELIVERY, STORAGE, AND HANDLING
Unit shall be stored and handled per manufacturer’s
recommendations.
PART 2 — PRODUCTS
2.01 EQUIPMENT (STANDARD)
A. General:
The unit shall be a factory assembled, single-piece heat-
ing and cooling unit. Contained within the unit enclosure
shall be all factory wiring, piping, controls, refrigerant
charge (R-22), and special features required prior to field
start-up.
B. Unit Cabinet:
1. Constructed of galvanized steel (G90 — 1.8 oz. of
zinc per square foot [550 grams per square meter] of
sheet metal), bonderized and primer-coated on both
sides and coated with a baked polyester thermoset-
ting powdercoating finish on the outer surface.
2. Indoor blower compartment interior surfaces shall be
insulated with a minimum 1 /
2
-in. thick, 1 lb density
fiberglass insulation.
3. Cabinet panels shall be easily removable for servic-
ing. Cabinet panels are minimum 20 gage. Panels
shall have
1 /
2
-in. thick, 1.5-lb. density insulation.
4. Filters shall be accessible through an access panel.
5. Holes shall be provided in the base rails (minimum
12 gage) for rigging shackles to facilitate overhead
rigging.
6. Unit shall contain a sloped drain pan, to prevent
standing water from accumulating. Pan shall be fabri-
cated of hot dipped zinc coated minimum spangle
steel. Zinc coating shall be G90 designation accord-
ing to ASTM Standard A653. Unit shall contain a
factory-installed nonferrous main condensate drain
connection.
C. Fans:
1. Indoor blower (evaporator fan):
a. Fan shall be belt driven. Belt drive shall include
an adjustable pulley. The standard fan drive shall
have a factory-installed low-medium static pres-
sure fan drive. The alternate fan drive option shall
have a factory-installed high static pressure fan
drive.
b. Fan wheel shall be made from steel with a corro-
sion resistant finish. It shall be a dynamically bal-
anced, double-inlet type with forward-curved
blades.
2. Condenser fans shall be of the direct-driven propeller
type, with corrosion-resistant blades riveted to corro-
sion-resistant steel supports. They shall be dynami-
cally balanced and discharge air upwards.
D. Compressor(s):
1. Fully hermetic, scroll type, internally protected.
2. Factory spring-shock mounted and internally spring
mounted for vibration isolation.
3. On electrically and mechanically independent refrig-
erant circuits.
4. All compressors shall have 70 W crankcase heaters.
E. Coils:
1. Standard evaporator and condenser coils shall have
aluminum plate fins mechanically bonded to seam-
less internally grooved copper tubes with all joints
brazed.
2. Coils shall be leak tested at 150 psig (1034 kPa) and
pressure tested at 450 psig (3103 kPa).
3. Optional precoated aluminum-fin coils shall have a
durable epoxy-phenolic coating to provide protection
in mildly corrosive coastal environments. Coating
shall be applied to the aluminum fin stock prior to the
fin stamping process to create an inert barrier
between the aluminum fin and copper tube. Epoxy-
phenolic barrier shall minimize galvanic action
between dissimilar metals.
4. Copper-fin coils shall be constructed of copper fins
mechanically bonded to copper tubes and copper
tube sheets. Galvanized steel tube sheets shall not
be acceptable. A polymer strip shall prevent coil
assembly from contacting the sheet metal coil pan to
minimize potential for galvanic corrosion between coil
and pan. All copper construction shall provide pro-
tection in moderate coastal environments.
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