Bryant 581A User Manual

Bryant

Air Conditioning

COMMERCIAL
SINGLE PACKAGE ROOFTOP
GAS HEATING/ELECTRIC COOLING UNITS

Model 581A

Sizes 155-240

13 to 20 Tons

Model 581A155,180

DESCRIPTION

The 581A gas heating/electric cooling rooftop units are de­signed to deliver optimum performance and reliability in a com­mercial rooftop unit.

The 13 to 20 ton units are one-piece gas heating, electric cool­ing units that are prewired and precharged with R-22 at the fac­tory, making jobsite installation easy. Every unit is factory run­tested prior to shipment to ensure reliable installation.

The 581A units are designed to be field-convertible from vertical
supply/return to horizontal supply/return (using an accessory
horizontal supply curb or adapter), making them easily adapt­able to a wide variety of new construction and replacement ap­plications. For vertical supply/return jobs, ductwork can be
connected directly to the roof curb, allowing ductwork to be
completed before unit is available for installation. All units in­clude easily replaceable internal filters.

The 581A units are available in a range of heating sizes and
voltage options to meet most job requirements. Low-voltage ter­minal blocks make wiring connections quick and simple.

All units are listed with ETL (ETL Testing Laboratory) and ETLC
(ETL Testing Laboratory for Canadian certification). All units are
ARI (Air-Conditioning & Refrigeration Institute) approved and
comply with ASHRAE Standard 62 (American Society of Heat­ing, Refrigeration, and Air Conditioning Engineers).

STANDARD FEATURES

INDUSTRY-LEADING COOLING EERS (Energy Efficiency Ra-

tios) assure minimum operating costs and will qualify for attrac­tive utility rebates in many areas.

SEMI-HERMETIC COMPRESSORS are fully serviceable. They
are highly regarded and preferred by owners and users, and are
offered exclusively on the high-efficiency 13 to 20 ton 581A
units.

Two 06D semi-hermetic compressors on independent refrigera­tion circuits are offered on the 180 and 240 units for 2 steps of
capacity control and redundancy. A single 06D semi-hermetic
compressor with unloading capability is offered on the 155 units.
All compressors have service valves and a full complement of

Model 581A240

safety devices, including high- and low-pressure switches, over­temperature protection, an electronic compressor lockout de­vice, and crankcase heaters.

HIGH STATIC OVERSIZED FAN MOTORS AND VARIABLE­PITCH BELT DRIVES are supplied standard from the factory to

provide up to 2 in. wg of external static pressure at 400 cfm per
ton with wet coils and clean filters installed. A 5 hp motor is pro­vided standard on the 581A180 (15-ton unit), and a 10 hp motor
is standard on the 581A240 (20-ton unit).

EASY INSTALLATION makes these units perfect for vertical
supply and return roof curb mount applications on new con­struction, retrofit, and replacement applications. The unique
industry-leading compact size and weight are favored by de­signers, contractors, owners, and users, and are significant ad­vantages in terms of minimizing required roof structures on new
construction and retrofit jobs.

The new 581Aunitscanbeeasily converted to horizontal supply
and return with the new fan-performance-boosting horizontal
high-static regain adapter (part no. 389210-201 or 389211-201).
These vertical-to-horizontal supply/return adapters are not only
fully factory assembled with a built-in insulated transition duct,
they improve fan performance by as much as 0.6 in. wg of
static.

THE FACTORY-ASSEMBLED PACKAGE is a compact, fully
self-contained electric cooling/gas heating unit that is prewired,
prepiped, and precharged for minimum installation expense.

INTERNAL RETURN-AIR FILTERS are provided. Two-in.
throwaway filters are provided standard on all units, and can be
easily accessed. There is no need to field-fabricate filter racks
or install external filter accessories.

COMPRESSOR PROTECTION is assured. The 581A units
have high- and low-pressure protection external to the compres­sor. These protections prohibit operation under abnormal unit
conditions.

DUAL COMPRESSORS AND DUAL REFRIGERATION CIR­CUITS (180,240 units) are provided. Two compressors, each

on its own independent circuit, provide standby reliability and
high operating efficiency.

POWER, CONTROL, AND GAS CONNECTIONS are made on
the same side of the unit to simplify installation.

Form No. PDS 581A.155.2B

INDUCED-DRAFT COMBUSTION provides the exact amount
of combustion air for the most efficient operation. Induced-draft
combustion also eliminates the flue stack, giving the unit a low
profile appearance. The draw-through design ensures safe op­eration under any conditions.

INTERMITTENT SPARK IGNITION eliminates the standing pi­lot flame that consumes gas when the furnace is shut down. The
pilot is ignited only when the thermostat calls for heat.

TUBULAR U-SHAPED CELL design of the heat exchanger
provides high-efficiency heating operation. The hot gases make
2 passes over the supply-air path to enhance efficiency.

POSITIVE-PRESSURE MECHANICAL FLUE GAS VENTING

is unaffected by adverse wind conditions.
FURNACE SAFETY CONTROLS shut off gas if there is a pilot

outage, combustion-air failure, overheating of heat exchangers,
or flame rollout.

TWO-STAGE HEATING WITH 2 INDEPENDENT GAS CON­TROL SYSTEMS (180,240 units) minimizes heating costs.

These independent gas control systems make single-stage
heating possible if one stage fails.

ADVANCED DESIGN of evaporator and condenser coils pro­vides optimum heat transfer and cooling efficiency. Coils are
computer-designed with advanced heat transfer surfaces, and
are fabricated of copper tubing with aluminum fins.

COMMERCIAL STRENGTH BASE RAILS with built-in rigging
capability allow easy rigging of unit.

WEATHER-RESISTANT CABINET is built for durability in any
climate. The cabinet is made of pre-painted, galvanized steel for
long life and high-quality appearance.

LOW-AMBIENT OPERATION is provided standard. The units
operate in cooling down to 35 F as shipped from the factory.
Low-ambient kits are not required for most applications.

COMPRESSOR VIBRATION ISOLATION MOUNTING on all
units eliminates noise-causing vibration transmission into the
conditioned space.

CRANKCASE HEATERS keep the oil free of refrigerant during
the off cycle for added compressor life and reliability.

STANDARD WARRANTIES include 1 year on parts (no labor),
with an additional 4 years on compressors (155 units) and
heat exchangers (all units). Additional extended warranties are
available.

BELT-DRIVEN EVAPORATOR-FAN MOTORS are standard on
all units and allow adjustment of the available static pressure to
meet the job requirements of even the most demanding
applications.

Manual Outdoor-Air Dampers — Package consists of a
damper which can be set at 25% outdoor air. The package in­cludes a rainhood and birdscreen.

SUGGESTED USE

• To allow a fixed percentage of outdoor air for ventilation under
all conditions.

• The damper may be used on either vertical or horizontal
applications.

NOTE: The 25% manual outdoor-air damper will be factory
installed whenever the factory-installed economizer is not
chosen.

FIELD-INSTALLED ACCESSORY

DESCRIPTION AND USAGE

Roof Curbs (Horizontal and Vertical) — Full-perimeter galva-

nized steel support frame in 14- and 24-in. high designs pro­vides wood nailer to attach roof counter flashing. Insulated
basepans in curb are provided to prevent condensation. Duct­work attaches to rails provided in the roof curb. A gasket is pro­vided to form an air- and watertight seal between unit and curb.
The gasket meets the standards of the NRCA (National Roofing
Contractors’ Association).

SUGGESTED USE:

• Rooftop application for vertical or horizontal discharge.

• Slab-mounted applications when elevation of the unit is
necessary.

Horizontal Adapter — The adapter is prefabricated, factory­assembled with built-in insulated duct, and permits full perim­eter mounting.

SUGGESTED USE:

• Rooftop applications for horizontal discharge where high air
delivery cfms are required.

Two-Position Damper — Package consists of a low-leak
damper assembly for easy installation. The damper will allow ei­ther 0 or 25% outdoor air into the unit any time the evaporator
fan is running. When the evaporator fan is off or when there is a
loss of power, the damper will be closed.

SUGGESTED USE:

• Allows a fixed percentage of outdoor air any time the evapo­rator fan is on, but closes when the evaporator fan is off to
prevent cold backdrafts and wasted energy.

• The damper may be used on either vertical or horizontal air­flow applications.

Economizer — See description listed under Factory-Installed
Options Description and Usage section above.

FACTORY-INSTALLED OPTIONS DESCRIPTION

AND USAGE

Economizer — The economizer will allow a fixed percentage

(between 0 and 100%) outdoor ventilation air into the unit any
time the evaporator fan is running. A dry-bulb thermostat placed
outdoors will bring in 100% outdoor air whenever the tempera­ture of the outdoor air alone will adequately provide cooling. If
the economizer alone cannot provide enough cooling, then si­multaneous economizer and compressor operation will provide
the most economical operation.

SUGGESTED USE:

• To allow a fixed percentage of outdoor air any time the evapo­rator fan is on, or operates in economizer mode if outdoor air
can provide cooling, but closes when the evaporator fan is off
to prevent cold backdrafts and wasted energy.

• To reduce energy usage. Use whenever the number of hours
of operation at below 55 F is significant.

• The damper may be used on either vertical or horizontal
applications.

CONTENTS

Page

Model Description .................................3

Heating Capacities and Efficiencies ...................4

Capacity Ratings ..................................4

Dimensional Drawings ............................5-8

Specifications ...................................9,10

Selection Procedure ..............................11

Gross Cooling Capacities ........................12-14

Air Delivery ....................................15-17

Electrical Data ...................................19

Operating Sequence ..............................20

Typical Wiring Schematic .........................20,21

Typical Installation ................................22

Application Data ................................23,24

Engineers’ Specification Guide ......................25

2

FIELD-INSTALLED ACCESSORY DESCRIPTION AND USAGE (cont)

Thermostats and Subbases — Provide staged cooling and

heating, automatic (or manual) changeover, fan control, and in­dicator light.

SUGGESTED USE:

• To control unit operations.
Enthalpy Control Sensor — Package consists of a solid-state

sensor to be paired with a second enthalpy sensor for differen­tial enthalpy control. This sensor is mounted on the economizer
assembly so that it can sense building return-air temperature.
The 2 sensors will determine which combination of outdoor and
return air will provide the greatest energy savings.

SUGGESTED USE:

• To enhance economizer operation for maximum energy
savings.

NOTE: A single sensor may be used for single-sensor, outdoor­air, enthalpy control if desired.

Time GuardT II Device — Package consists of a control to be
field wired into the unit controls, and provides a 5-minute delay
in compressor operation between cooling cycles.

SUGGESTED USE:

• Prevents compressor short cycling when rapid compressor
cycles may be a problem.

Head Pressure Control Device — Kit consists of an outdoor­air thermostat that permits adequate head pressure control dur­ing cooling operation at low outdoor-ambient temperatures.
Refer to Trade Prices for more details or contact your local
representative.

SUGGESTED USE:

• When cooling at low-ambient outdoor temperatures is
desired.

Low-Ambient Kit — Kit consists of a solid-state control and
condenser coil temperature sensor to modulate the condenser­fan motors in order to maintain condenser-coil head pressure

for proper cooling operation. Refer to Trade Prices for more de­tails or contact your local representative.

SUGGESTED USE:

• Whenever cooling is required at low outdoor ambient tem­peratures (as low as –20 F).

• Low-ambient kit is not usually required when economizer is
used.

Barometric Relief Package — This package is useful when it
is necessary to remove excess pressure from the conditioned
space.

NOTE: Optional economizer is required.
SUGGESTED USE:

• When the job requires the ability to relieve internal building
pressure.

Power Exhaust Package — This package is useful when it is
necessary to remove excess pressure from the conditioned
space.

NOTE: Optional economizer is required.
SUGGESTED USE:

• When the job requires the ability to relieve internal building
pressure and pressure losses through the return-air ductwork
are greater than 0.20 in. wg.

• When the job requires the ability to move large quantities of
air to relieve pressure in the conditioned space.

Winter Start Time Delay Relay — Used in conjunction with ac­cessory low-ambient kit or head pressure control device, per­mits operation in cooling at lower outdoor ambient tempera­tures. See Trade Prices for more details or contact your local
representative.

SUGGESTED USE:

• When job requires the ability to operate in cooling at low
outdoor-ambient temperatures.

LEGEND

ODS — Order Distribution System

MODEL DESCRIPTION

(ODS Model Number)

3

HEATING CAPACITIES AND EFFICIENCIES

UNIT 581A

155 154 —/154,000 123,000 15-45 80 2485
155 231 231,000/115,500 185,000 25-55 80 3057
180 270 270,000/115,500 216,000 15-45 80 4364
240 270 270,000/115,500 216,000 15-45 80 4364
240 485 485,000/242,500 388,000 35-65 80 5427

HEATING INPUT

(Btuh)

Stage 2/Stage 1

OUTPUT CAPACITY

(Btuh)

TEMPERATURE

RISE (F)

STEADY-STATE

EFFICIENCY

(%)

MINIMUM
HEATING

CFM

CAPACITY RATINGS

UNIT 581A

155 13 146,000 13.91 10.5 12.8
180 15 186,000 18.05 10.3 10.5
240 20 234,000 25.29 9.3 9.3

ARI — Air Conditioning and Refrigeration Institute
EER — Energy Efficiency Ratio
IPLV — Integrated Part-Load Values

NOTE:

Rated in accordance with ARI Standards 360-86.
Ratings are net values, reflecting the effects of circulating fan heat.
Ratings are based on:

NOMINAL

TONS

LEGEND

NET COOLING

(Btuh)

TOTAL

kW

EER IPLVCAPACITY

Cooling Standard: 80 F db, 67 F wb indoor entering-air temperature and 95 F db air entering out-

door unit.
IPLV Standard: 80 F db, 67 F wb indoor entering-air temperature and 80 F db outdoor entering-air

temperature.

4

DIMENSIONAL DRAWING — 581A155,180

UNIT

MAXIMUM SHIPPING

581A

WEIGHT

155 154 1920 871
155 231 1940 880
180 270 2310 1048

UNIT
581A

WEIGHT OF CORNER* DIMENSIONS

ABCD X Y Z

Lb Kg Lb Kg Lb Kg Lb Kg Ft-in. mm Ft-in. mm Ft-in. mm

155 154 365 166 360 163 373 169 540 245 3-2 965 3-1
155 231 372 169 363 165 377 171 547 248 3-2 965 3-1
180 270 509 231 506 230 475 216 519 235 3-7

3

⁄81102 3-43⁄81035 1- 8 508

*Weights are for unit only and do not include options or crating.

NOTES:

1. Dimensions in ( ) are in millimeters.

2. Center of gravity.

3. Direction of airflow.

4. Ductwork to be attached to accessory roof curb only.

5. Minimum clearance:
a. Rear: 78-09 (2134) for coil removal. This dimension can be reduced to

48-09 (1219) if conditions permit coil removal from the top.
b. Left side: 48-09 (1219) for proper condenser coil airflow.
c. Front: 48-09 (1219) for control box access.
d. Rightside: 48-09 (1219) for proper operation of damper and power ex-

haust (if so equipped).
e. Top: 68-09 (1829) to assure proper condenser fan operation.
f. Local codes or jurisdiction may prevail.

6. With the exception of clearance for the condenser coil and the damper/
power exhaust as stated in Note No. 5, a removable fence or barricade
requires no clearance.

7. Dimensions are from outside of corner post. Allow 08­side for top cover drip edge.

3

⁄8949 1-10 559

1

⁄4946 1-10 559

5

⁄169 (8) on each

5

DIMENSIONAL DRAWING — 581A240

UNIT
581A

ABCD A B C D E

Lb Kg Lb Kg Lb Kg Lb Kg Ft-in. mm Ft-in. mm Ft-in. mm Ft-in. mm Ft-in. mm

240 270 523 237 541 245 574 260 596 270 3-4 1016 3-7 1092 0-3 76 6-11
240 485 465 211 486 220 725 329 737 334 4-2 1270 3-5 1041 0-4

CORNER WEIGHT* DIMENSIONS

1

⁄2114 8- 71⁄42623 3-35⁄81006

*Weights are for unit only and do not include options or crating.

UNIT
581A

240 270 2514 1140
240 485 2793 1267

1

⁄22121 1-713⁄16504

MAXIMUM SHIPPING

WEIGHT

Lb Kg

NOTES:

1. Dimensions in ( ) are in millimeters.

2. Center of gravity.

3. Direction of airflow.

4. Ductwork to be attached to accessory roof curb only.

5. Minimum clearance:
a. Rear: 7809 (2134) for coil removal. This dimension

can be reduced to 4809 (1219) if conditions permit
coil removal from the top.

b. 4809 (1219) to combustible surfaces, all four sides

(includes between units).

c. Left side: 4809 (1219) for proper condenser coil

airflow.
d. Front: 4809 (1219) for control box access.
e. Right side: 4809 (1219) for proper operation of

damper and power exhaust (if so equipped).
f. Top: 6809 (1829) to assure proper condenser fan

operation.
g. Bottom: 149 (356) to combustible surfaces (whennot

using curb).
h. Control box side: 3809 (914) to ungrounded surfaces

(non-combustible).
i. Control box side: 3869 (1067) to block or concrete

walls, or other grounded surfaces.
j. Local codes or jurisdiction may prevail.

6. With the exception of clearance for the condenser coil
and the damper/power exhaust as stated in Note No. 5,
a removable fence or barricade requires no clearance.

7. Dimensions are from outside of corner post. Allow

5

⁄169 (8) on each side for top cover drip edge.

08-

6

DIMENSIONAL DRAWING — HORIZONTAL AND VERTICAL ROOF CURBS AND HORIZONTAL ADAPTER

NOTE: To prevent the hazard of stagnant water build-up in the drain pan

of the indoor-air section, unit can only be pitched as shown.

ACCESSORY

PACKAGE

NO.

308450-201

308450-202

308450-203

389210-201

389171-201*

389171-202*

389171-203*

389211-201*

CURB

HEIGHT

18-29 Standard Curb — 58-7

(355) 149 High (1703) (503)

28-09

(610)

28-09

(610)

18-119

(584)

18-29 Standard Curb — 78-2

(355) 149 High (2205) (1006)

28-09

(610)

28-09

(610)

18-119

(584)

DESCRIPTION ‘‘A’’ ‘‘B’’ ‘‘C’’ ‘‘D’’ ‘‘E’’

Standard Curb for

High Installation

Horizontal Supply and 58-7

Pre-Assembled, High-Static,

Horizontal Adapter

Standard Curb

High Installation

Horizontal Supply 78-2

Pre-Assembled, High-Static,

Horizontal Adapter

*For 581A240 high-heat applications.

COMPR SECT. — Compressor Section

LEGEND

NOTES:

1. Roof curb accessory is shipped unassembled.

2. Insulated panels,

3. Dimensions in ( ) are in millimeters.

1

⁄2-in. thick neoprene-coated, 2 lb density.

4. Direction of airflow.

5. Roof curb: 18 gage steel.

6. Attach all ductwork to roof curb.

7. Field installation of sidewall insulation is mandatory.

1

⁄169 18-713⁄

1

⁄

16

58-7

(1703)

1

⁄

16

(1703)

1

⁄

16

58-7

(1703)

13

⁄169 38-35⁄

13

⁄

16

78-2

(2205)

13

⁄

16

(2205)

13

⁄

16

78-2

(2205)

9

9

9

9

9

9

18-713⁄

(503)

18-713⁄

(503)

18-713⁄

(503)

38-35⁄
(1006)

38-35⁄
(1006)

38-35⁄
(1006)

16

9

———

16

9

———Units Requiring

16

9

58-69

(1676)

16

9

68-29

(1880)

8

9

8

9

8

9

58-69

(1676)

8

9

68-29

(1880)

08-21⁄

2

(64)

08-61⁄

4

(159)

———

———for Units Requiring

08-21⁄

2

(64)

08-61⁄

4

(159)

9

18-69

(457)Return Curb

9

18-25⁄

8

9

(371)

9

18-69

(457)and Return Curb

9

18-25⁄

8

9

(371)

7

DIMENSIONAL DRAWING — HORIZONTAL ADAPTER INSTALLATION

NOTES:

1. The 389210-201 and 389211-201 are fully factory-preassembled hori­zontal adapters which include an insulated high-static regain transition
duct to substantially improve fan static performance.

2. Power exhaust and barometric relief accessories cannot be used with
factory pre-assembled, high-static, horizontal adapters.

8