Bryant SINGLE PACKAGE ROOFTOP ELECTRIC COOLING/GAS HEATING UNITS 581A User Manual

Page 15

—15—

NOTE:

When compressors are rotating in the wrong direc-

tion, the unit will have increased noise levels and will not
provide heating and cooling.

After a few minutes of reverse operation, the scroll compres-
sor internal overload protection will open, which will acti-
vate the unit’s lockout and requires a manual reset. Reset is
accomplished by turning the thermostat on and off.

VI. INTERNAL WIRING

Check all electrical connections in unit control boxes; tighten
as required.

VII. CRANKCASE HEATER(S)

Crankcase heater(s) is energized as long as there is power to
the unit and the compressor is not operating.

IMPORTANT:

Unit power must be on for 24 hours prior to

start-up. Otherwise, damage to compressor may result.

VIII. EVAPORATOR FAN

Fan belt and variable pulleys are factory-installed. Remove
tape from the fan pulley. See Tables 3-10 for Fan Perfor-
mance Data. Be sure that fans rotate in the proper direction.
See Table 11 for air quantity limits. See Table 12 for Evapo-
rator Fan Motor Specifications. See Table 13 for static pres-
sure information for accessories and options. See Table 14 for
fan rpm at various motor pulley settings. To alter fan perfor-

mance, see Evaporator Fan Performance Adjustment section
on page 26.

NOTE:

A 3

-in. bolt and threaded plate are included in the

installer’s packet. They can be added to the motor support
channel below the motor mounting plate to aid in raising the
fan motor.

IX. CONDENSER FANS AND MOTORS

Condenser fans and motors are factory set. Refer to Con-
denser-Fan Adjustment section (page 27) as required. Be
sure that fans rotate in the proper direction.

X. RETURN-AIR FILTERS

Check that correct filters are installed in filter tracks (see
Table 1). Do not operate unit without return-air filters.

XI. OUTDOOR-AIR INLET SCREENS

Outdoor-air inlet screens must be in place before operating
unit.

XII. ACCESSORY ECONOMIZER ADJUSTMENT

Remove filter access panel. Check that outdoor-air damper is
closed and return-air damper is open.

Economizer operation and adjustment are described in Base
Unit Operation section on page 24, and in Economizer
Adjustment section on page 28.

Table 3 — Fan Performance — 581A155225 (Low Heat Units with Standard Indoor Fan Motor)

LEGEND

*Standard low-medium static drive range is 834 to 1064 rpm. Alternate

high-static drive range is 1161 to 1426. Other rpms require a field-
supplied drive.

NOTES:
1. Maximum continuous bhp for the standard motor is 3.13. The maxi-

mum continuous watts is 2700. Do not adjust motor rpm such that
motor maximum bhp and/or watts is exceeded at the maximum
operating cfm.

2. Static pressure losses (i.e., economizer) must be added to external

static pressure before entering Fan Performance table.

3. Interpolation is permissible. Do not extrapolate.
4. Fan performance is based on wet coils, clean filters, and

casing losses. See Table 13 for accessory/FIOP static pressure
information.

5. Extensive motor and drive testing on these units ensures that the full

bhp and watts range of the motor can be utilized with confidence.
Using your fan motors up to the watts or bhp rating shown will not
result in nuisance tripping or premature motor failure. Unit warranty
will not be affected.

6. Use of a field-supplied motor may affect wiring size. Contact your

Bryant representative for details.

CFM

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)

0.2

0.4

0.6

0.8

1.0

Rpm

Watts

Bhp

Rpm

Watts

Bhp

Rpm

Watts

Bhp

Rpm

Watts

Bhp

Rpm

Watts

Bhp

3750

753

915

1.05

838

1066

1.23

945

1278

1.47

1044

1500

1.73

1138

1731

1.99

4000

755

991

1.14

865

1198

1.38

968

1414

1.63

1063

1639

1.89

1154

1873

2.15

4250

788

1129

1.30

894

1341

1.54

992

1562

1.80

1084

1791

2.06

1172

2029

2.33

4500

822

1280

1.47

923

1497

1.72

1017

1722

1.98

1106

1956

2.25

1191

2196

2.53

4750

857

1443

1.66

953

1666

1.92

1044

1896

2.18

1130

2133

2.45

1212

2377

2.73

5000

891

1620

1.86

984

1847

2.12

1071

2082

2.39

1154

2323

2.67

1234

2572

2.96

5250

927

1810

2.08

1015

2043

2.35

1099

2282

2.62

1180

2528

2.91

—

5500

962

2014

2.32

1047

2252

2.59

1129

2496

2.87

—

5750

998

2233

2.57

1080

2476

2.85

—

6000

1035

2466

2.84

—

CFM

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)

1.2

1.4

1.6

1.8

2.0

Rpm

Watts

Bhp

Rpm

Watts

Bhp

Rpm

Watts

Bhp

Rpm

Watts

Bhp

Rpm

Watts

Bhp

3750

1226

1971

2.27

1311

2218

2.55

1391

2474

2.85

—

4000

1240

2116

2.43

1322

2366

2.72

1401

2623

3.02

—

4250

1255

2274

2.61

1335

2526

2.91

—

4500

1272

2444

2.81

1350

2700

3.10

—

4750

1291

2628

3.02

—

5000

—

5250

—

5500

—

5750

—

6000

—

Bhp

— Brake Horsepower

FIOP — Factory-Installed Option
Watts — Input Watts to Motor