Table 9 — Typical Unit Operating Pressures and Temperatures

ENTERING

WATER

 

 

 

COOLING

 

 

 

 

 

HEATING

 

 

WATER

FLOW

Suction

Discharge

Super-

Sub-

Water Temp

Air Temp

Suction

Discharge

Super-

Sub-

Water Temp

Air

TEMP (C)

Pressure

Pressure

heat

cooling

Rise

Drop (C)

Pressure

Pressure

heat

cooling

Temp

(l/s per kW)

(EWT)

 

(kPa)

(kPa)

(C)

(C)

(C)

 

DB

(kPa)

(kPa)

(C)

(C)

Drop (C) DB

Rise (C)

–1

0.027

225-254

269-314

14-22

7-11

12-13

12-14

102-117

499-556

7- 9

1-2

4-5

8-11

0.041

222-251

239-284

14-22

6-10

7-

9

12-14

111-129

514-571

7- 9

1-2

3-4

9-12

 

0.054

219-248

209-254

14-22

6-

9

3-

6

12-14

120-138

529-586

7- 9

1-2

2-3

9-12

10

0.027

225-254

374-463

7-11

6-10

11-13

11-14

150-179

538-628

6- 9

1-3

6-7

13-16

0.041

222-251

359-425

7-11

5-

9

7-

8

11-14

158-185

553-643

6- 9

1-3

4-5

13-17

 

0.054

219-248

344-413

7-11

4-

8

4-

7

11-14

164-194

568-658

6- 9

1-3

3-4

14-17

21

0.027

225-254

535-592

5-

9

4-

8

11-12

11-13

212-245

613-688

8-11

1-3

8-9

16-19

0.041

222-251

502-556

5-

9

4-

7

7-

9

11-13

218-254

628-712

8-11

1-3

5-6

17-21

 

0.054

219-248

472-523

5-

9

4-

7

4-

7

11-13

227-263

643-724

8-11

1-3

3-4

17-21

32

0.027

225-254

685-750

5-

9

4-

8

10-12

9-13

254-284

658-777

10-16

1-3

8-9

18-22

0.041

222-251

652-721

5-

9

4-

7

6-

8

9-13

269-299

673-792

10-16

1-3

6-7

18-23

 

0.054

219-248

622-688

5-

9

4-

7

3-

6

9-13

284-314

688-807

10-16

1-3

4-5

19-23

43

0.027

231-260

837-957

4-

8

6-14

9-11

8-11

 

 

 

 

 

 

0.041

228-257

807-927

4-

8

6-13

5-

7

8-11

 

 

 

 

 

 

 

0.054

225-254

777-897

4-

8

6-12

3-

6

8-11

 

 

 

 

 

 

LEGEND

DB — Dry Bulb

EAT — Entering Air Temperature

NOTES:

1.Based on nominal 54 L/s per kW airflow and 21° C EAT heating and 26.7/ 194° C EAT cooling.

2.Cooling air and water numbers can vary greatly with changes in humidity.

3.Subcooling is based upon the head pressure at compressor service port.

Table 10 — 50RHE Coaxial Water Pressure Drop

UNIT

L/S

 

PRESSURE DROP (kPa)

 

50RHE

0° C

10° C

20° C

 

30° C

 

 

006

0.047

6.0

5.4

5.1

 

4.8

0.071

8.4

7.8

7.2

 

6.9

 

0.095

14.1

13.2

12.0

 

11.7

009

0.071

8.1

7.5

6.9

 

6.6

0.107

12.0

11.1

10.5

 

9.9

 

0.139

23.9

22.4

20.9

 

20.0

012

0.095

19.1

17.9

16.7

 

16.1

0.145

41.3

38.9

36.2

 

34.7

 

0.189

66.1

61.9

57.7

 

55.0

015

0.114

16.7

15.5

14.7

 

14.1

0.164

32.6

30.5

28.7

 

27.2

 

0.221

55.9

52.3

48.7

 

46.3

019

0.142

12.9

12.0

11.1

 

10.8

0.215

23.0

21.5

20.3

 

19.1

 

0.284

45.4

42.5

39.8

 

37.7

024

0.189

13.8

12.6

11.7

 

11.4

0.284

28.7

26.9

25.1

 

23.9

 

0.379

47.8

44.9

41.9

 

39.8

030

0.237

9.9

9.0

8.4

 

8.1

0.347

17.0

15.8

14.7

 

14.1

 

0.473

26.9

25.4

23.6

 

22.4

036

0.284

7.8

7.2

6.9

 

6.6

0.426

15.0

13.8

12.9

 

12.3

 

0.568

23.9

22.4

20.9

 

20.0

042

0.331

9.9

9.3

8.7

 

8.4

0.498

19.7

18.5

17.0

 

16.4

 

0.663

31.1

29.3

27.5

 

26.0

048

0.379

14.1

13.2

12.3

 

11.7

0.568

26.9

25.4

23.6

 

22.4

 

0.757

44.0

41.0

38.3

 

36.5

060

0.473

33.5

31.4

29.3

 

27.8

0.713

58.3

54.4

50.8

 

48.4

 

0.947

88.5

82.8

77.1

 

73.3

Flushing — Once the piping is complete, units require final purging and loop charging. A flush cart pump of at least 1.5 hp (1.12 kW) is needed to achieve adequate flow velocity in the loop to purge air and dirt particles from the loop. Flush the loop in both directions with a high volume of water at a high velocity. Follow the steps below to properly flush the loop:

1.Verify power is off.

2.Fill loop with water from hose through flush cart before using flush cart pump to ensure an even fill. Do not allow the water level in the flush cart tank to drop below the pump inlet line to prevent air from filling the line.

3.Maintain a fluid level in the tank above the return tee to avoid air entering back into the fluid.

4.Shutting off the return valve that connects into the flush cart reservoir will allow 345 kPa surges to help purge air pockets. This maintains the pump at 345 kPa.

5.To purge, keep the pump at 345 kPa until maximum pumping pressure is reached.

6.Open the return valve to send a pressure surge through the loop to purge any air pockets in the piping system.

7.A noticeable drop in fluid level will be seen in the flush cart tank. This is the only indication of air in the loop.

NOTE: If air is purged from the system while using a 254 mm PVC flush tank, the level drop will only be 25 to 51 mm since liquids are incompressible. If the level drops more than this, flushing should continue since air is still being compressed in the loop. If level is less than 25 to 51 mm, reverse the flow.

8.Repeat this procedure until all air is purged.

9.Restore power.

Antifreeze may be added before, during or after the flushing process. However, depending on when it is added in the process, it can be wasted. Refer to the Antifreeze section for more detail.

Loop static pressure will fluctuate with the seasons. Pres- sures will be higher in the winter months than during the warm- er months. This fluctuation is normal and should be considered when charging the system initially. Run the unit in either heat- ing or cooling for several minutes to condition the loop to a homogenous temperature.

When complete, perform a final flush and pressurize the loop to a static pressure of 275 to 345 kPa for winter months or 105 to 135 kPa for summer months.

After pressurization, be sure to remove the plug from the end of the loop pump motor(s) to allow trapped air to be discharged and to ensure the motor housing has been flooded. Be sure the loop flow center provides adequate flow through the unit by checking pressure drop across the heat exchanger. Compare the results to the data in Table 10.

20

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Carrier 50RHE006-060 specifications Typical Unit Operating Pressures and Temperatures, 50RHE Coaxial Water Pressure Drop

50RHE006-060 specifications

The Carrier 50RHE006-060 is a robust commercial rooftop unit designed for efficient heating and cooling in various applications. This model is part of Carrier’s renowned line of HVAC systems, known for their reliability and performance. With a nominal cooling capacity of 5 tons and heating capacity of 6 tons, this unit is suitable for medium-sized commercial spaces such as retail stores, offices, and schools.

One of the standout features of the Carrier 50RHE006-060 is its advanced scroll compressor technology. This type of compressor is recognized for its efficiency and durability, offering quiet operation while minimizing energy consumption. The inclusion of a variable-speed blower motor enhances comfort by providing consistent airflow while also reducing energy costs by adjusting the speed according to the demand.

Another key characteristic is its integrated microprocessor control system, which allows for precise temperature management. This feature not only provides optimal comfort but also ensures energy savings. The system’s controls can be easily integrated with existing building management systems, allowing for seamless operation and monitoring.

The Carrier 50RHE006-060 boasts enhanced insulation properties, which help reduce noise during operation and improve energy efficiency. Its robust design can withstand various weather conditions, making it a reliable choice for rooftop installation. Moreover, it is designed with accessibility in mind, featuring service doors that allow for easy maintenance, reducing downtime and operational costs.

In terms of efficiency, the unit is designed to meet or exceed EPA energy efficiency standards. It utilizes environmentally friendly refrigerants, adhering to regulations aimed at reducing greenhouse gas emissions. Additionally, the design includes a high-efficiency heat exchanger, which maximizes heat transfer and improves overall performance.

The Carrier 50RHE006-060 is also equipped with a dual-stage heat function, allowing it to provide optimal heating for varying weather conditions, ensuring comfort during the colder months. Furthermore, the unit’s design incorporates features such as hot gas bypass for improved dehumidification, making it adaptable to different climates and enhancing indoor air quality.

In summary, the Carrier 50RHE006-060 stands out with its efficient compressor technology, smart control systems, robust construction, and environmentally conscious design. These features make it a top choice for commercial spaces seeking an effective, reliable, and energy-efficient heating and cooling solution.