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Cv unit start-up – Carrier OMNIZONE 50BV020-064 User Manual

Page 31

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when it starts. Also, no cooling will be produced at the

evaporator. If any of these conditions occurs, refer to the

Service section to correct the compressor rotation before

continuing.
INTERNAL WIRING — Check all electrical connections in

unit control boxes; tighten as required.
RETURN-AIR FILTERS — Check that correct filters are

installed in filter tracks (see Tables 3A and 3B). Do not operate

unit without return-air filters.
COMPRESSOR MOUNTING — Compressors are internal-

ly spring mounted. Do not loosen or remove compressor hold-

down bolts.
REFRIGERANT SERVICE PORTS — Each refrigerant system

has a total of 2 Schrader-type service gage ports per circuit. One

port is located on the suction line, and one on the compressor

discharge line. Be sure that caps on the ports are tight.

CV Unit Start-Up

EVAPORATOR FAN — Fan belt and variable pitch motor

pulleys are factory installed. See Tables 13-20

for fan perfor-

mance data. Be sure that fans rotate in the proper direction.

COOLING — Set the space thermostat to OFF position. Turn

on unit power. Set space thermostat to COOL and the fan to

AUTO. Adjust the thermostat temperature setting below room

temperature. Compressor 1 starts on closure of contactor (com-

pressors 1 and 2 on 4-circuit units with 2-stage thermostat).

Adjust the thermostat to an even lower setting until the ther-

mostat energizes Y2 (the second cooling stage). Compressor 2

starts on closure of contactor (compressors 3 and 4 on 4-circuit

units with 2-stage thermostat).

Adjust the thermostat temperature to a setting just below

room temperature. The second stage of cooling should turn off.

Set the thermostat temperature above room temperature. All

compressors and the unit fan should now be off.
HEATING (Heat Pump Units Only) — Follow the same se-

quence as for cooling (above), except set the space thermostat

to HEAT, and instead of adjusting the thermostat below room

temperature, adjust it above. Verify that the compressors turn

on and the unit runs in reverse cycle mode.

Set the thermostat below room temperature and confirm

that the compressors and fan turn off.

Table 13 — Fan Performance — 50BVC,E,Q020

LEGEND

NOTES:

1. Units are available with the following motor and drive combina-

tions: 1.5, 2, 3, 5 HP standard drive; 1.5, 2, 3 HP medium static
drive.
For 1.5, 2, 3 HP standard drives, the drive range is 753 to
952 rpm. For medium static drives, the drive range is 872 to
1071 rpm. For 5 HP standard drives, the drive range is 967 to
1290 rpm.

2. Italics indicates field-supplied drive required.
3.

Do not operate in shaded area.

4. Static pressure losses must be applied to external static pres-

sure before entering the fan performance table.

5. Interpolation is permitted, extrapolation is not.
6. Fan performance is based on filter, unit casing and wet coil

losses.

7. Bhp values are per fan. Watts values are per motor. Unit has

2 supply fans and 2 motors.

AIRFLOW

(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

4500

623

459

0.52

5000

638

545

0.61

5500

655

641

0.72

725

755

0.85

6000

608

641

0.72

676

755

0.85

742

878

0.99

807

1001

1.13

6500

636

755

0.85

699

878

0.99

761

1010

1.14

821

1142

1.29

7000

604

774

0.87

666

906

1.02

726

1029

1.16

784

1170

1.32

841

1311

1.48

7500

634

916

1.03

693

1057

1.19

750

1189

1.34

805

1330

1.50

858

1480

1.67

8000

667

1085

1.22

723

1226

1.38

777

1377

1.55

829

1526

1.72

880

1676

1.89

8500

700

1273

1.43

753

1423

1.60

804

1573

1.77

853

1732

1.95

902

1836

2.13

9000

735

1480

1.67

785

1638

1.84

833

1745

2.02

881

1908

2.21

927

2071

2.40

AIRFLOW

(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

4500

5000

5500

6000

6500

881

1283

1.44

7000

897

1451

1.63

951

1601

1.80

7500

911

1629

1.83

963

1727

2.00

1014

1881

2.18

8000

930

1781

2.07

979

1935

2.24

1028

2098

2.43

1076

2260

2.62

1124

2422

2.81

8500

950

1989

2.31

997

2152

2.50

1043

2323

2.69

1089

2485

2.88

1134

2697

3.09

9000

973

2233

2.59

1018

2404

2.79

1062

2576

2.99

1106

2779

3.18

1149

2960

3.39

Bhp

Brake Horsepower Input to Supply Fan

Watts — Input Power to Supply Fan Motor