Bryant COMMERCIAL SINGLE PACKAGE ROOFTOP GAS HEAT/ELECTRIC COOLING 581B User Manual

Page 60

GUIDE SPECIFICATIONS

PACKAGED ROOFTOP COOLING UNIT WITH GAS HEAT —
CONSTANT VOLUME APPLICATION
HVAC GUIDE SPECIFICATIONS

SIZE RANGE: 3 TO 12

TONS, NOMINAL COOLING

72,000 TO 250,000 BTUH,
NOMINAL INPUT HEATING

BRYANT MODEL NUMBER: 581B

PART 1 — GENERAL
1.01 SYSTEM DESCRIPTION

Outdoor rooftop- or slab-mounted, electrically controlled
heating and cooling utilizing a scroll compressor for cool-
ing duty and gas combustion for heating duty. Unit shall
discharge supply air vertically or horizontally as shown on
contract drawings.

1.02 QUALITY ASSURANCE

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

240 or 360 and 270.

B. Unit shall be designed to conform to ASHRAE 15, latest

revision, and in accordance with UL 1995.

C. Unit shall be UL tested and certified in accordance with

ANSI Z21.47 Standard and UL listed and certified under
Canadian Standards as a total package for safety
requirements.

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 exceeding Federal Test

Method Standard No. 141 (Method 6061) 500-hour Salt
Spray Test.

G. Each 581B unit is subjected to completely automated run

testing on the assembly line. Each unit contains a factory-
supplied printout indicating tested pressures, amperages,
data, and inspectors; providing certification of the unit
status at the time of manufacture.

1.03 DELIVERY, STORAGE, AND HANDLING

Unit(s) shall be stored and handled per manufacturer’s
recommendations.

PART 2 — PRODUCTS
2.01 EQUIPMENT (STANDARD)

A. General:

Factory-assembled, single-piece heating 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. Unit cabinet shall be constructed of galvanized steel,

bonderized and coated with a baked enamel finish
on all externally exposed surfaces, and have primer-
coated interior surfaces on all panels.

2. Evaporator-fan cabinet interior shall be insulated with

a minimum

-in. thick flexible fiberglass insulation

coated on the air side. Aluminum foil-faced fiberglass
insulation shall be used in the heating compartment.

3. Cabinet panels shall be easily removable for

servicing.

4. Holes shall be provided in the base rails for rigging

shackles to facilitate overhead rigging, and forklift
slots shall be provided to facilitate maneuvering.

5. Unit shall have a factory-installed, sloped conden-

sate drain pan made of a non-corrosive material, pro-
viding a minimum

-in. connection with both vertical

and horizontal drains and shall comply with
ASHRAE 62.

6. Unit shall have factory-installed filter access panel to

provide filter access with tool-less removal.

7. Unit shall have standard thru-the-bottom power con-

nection capability.

C. Fans:

1. Indoor blower (evaporator fan) shall be of the

belt-driven, double inlet, forward-curved centrifugal
type. Belt drive shall include an adjustable-pitch
motor pulley.

2. Indoor blower (evaporator fan) shall be made from

steel with a corrosion-resistant finish and shall be
dynamically balanced.

3. Bearings shall be of the sealed, permanently lubri-

cated, ball-bearing type for longer life and lower
maintenance.

4. Condenser fan shall be of the direct-driven propeller

type and shall discharge air vertically upward.

5. Condenser fan shall have aluminum blades riveted to

corrosion-resistant steel spiders and shall be dynam-
ically balanced.

6. Condenser-fan motor shall be totally enclosed.
7. Induced draft blower shall be of the direct-driven, sin-

gle inlet, forward curved, centrifugal type, shall be
made from steel with a corrosion-resistant finish, and
shall be dynamically balanced.

D. Compressor(s):

1. Fully hermetic scroll type, internally protected.
2. Factory rubber-shock mounted and internally spring

mounted for vibration isolation.

3. On independent circuits (sizes 090-150).

E. Coils:

1. Evaporator and condenser coils shall have aluminum

plate fins mechanically bonded to enhanced copper
tubes with all joints brazed.

2. Tube sheet openings shall be belled to prevent tube

wear.

3. Evaporator coil shall be of the face-split design.

F. Heating Section:

1. Induced draft combustion type with energy saving

direct spark ignition system, redundant main gas
valve.

2. The heat exchanger shall be of the tubular section

type constructed of a minimum of 20 gage steel
coated with a nominal 1.2 mil aluminum-silicone alloy
for corrosion resistance.

3. Burners shall be of the in-shot type constructed of

aluminum coated steel.

4. All gas piping shall enter the unit cabinet at a single

location.

5. The Integrated Gas Control (IGC) board shall provide

timed control of evaporator fan functioning and
burner ignition. An LED (light-emitting diode) shall
provide diagnostic information. The LED shall be vis-
ible without removing the control box access panel.

6. IGC board contains anti-cycle protection for gas heat

operation (after 4 continuous cycles on high temper-
ature limit switch and one cycle on the flame rollout
switch).

G. Refrigerant Components:

Refrigerant circuit components shall include:

1. Fixed-orifice type feed system.
2. Refrigerant strainer.
3. Service gage connections on suction, discharge, and

liquid lines.

4. Filter drier.
5. Ability to route gage hoses through unit top cover

(unit sizes 036-072 only).

H. Filter Section:

1. Standard filter section shall consist of factory-

installed low-velocity, throwaway 2-in. thick fiberglass
filters of commercially available sizes.

2. Filter face velocity shall not exceed 300 fpm at nomi-

nal airflows.

3. Filter section shall use only one size filter.
4. Filters shall be accessible through an access panel

with ‘‘no-tool’’ removal.