Flow regulation, Flushing, Antifreeze – Carrier AQUAZONE PSV User Manual

Page 41: Warning

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41

f. Press OK to apply and save to a particular day of

the week.

g. Continue to add the same or different schedule spe-

cific days of the week.
To add exceptions to the schedule:
i. Press Add softkey.
ii. Select exception type from following:

• Date

• Date Range

• Week-N-Day

• Calender Reference

9. Go back to Home Screen.

10. Remove BACview

6

cable from SPT sensor by reversing

the process in Step 1.

11. Perform system test.

Flow Regulation —

Flow regulation can be accom-

plished by two methods. Most water control valves have a flow

adjustment built into the valve. By measuring the pressure drop

through the unit heat exchanger, the flow rate can be deter-

mined. See Table 31. Adjust the water control valve until the

flow of 1.5 to 2 gpm is achieved. Since the pressure constantly

varies, two pressure gages may be needed in some

applications.

Table 31 — 50PSH, PSV, PSD Coaxial

Water Pressure Drop

An alternative method is to install a flow control device.

These devices are typically an orifice of plastic material de-

signed to allow a specified flow rate that are mounted on the

outlet of the water control valve. Occasionally these valves

produce a velocity noise that can be reduced by applying some

back pressure. To accomplish this, slightly close the leaving

isolation valve of the well water setup.

Flushing —

Once the piping is complete, units require final

purging and loop charging. A flush cart pump of at least 1.5 hp

is needed to achieve adequate flow velocity in the loop to purge

air and dirt particles from the loop. Flush the loop in both direc-

tions 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 in order to prevent air from filling the line.

3. Maintain a fluid level in the tank above the return tee in

order to avoid air entering back into the fluid.

4. Shutting off the return valve that connects into the flush

cart reservoir will allow 50 psig surges to help purge air

pockets. This maintains the pump at 50 psig.

5. To purge, keep the pump at 50 psig 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

10 in. PVC flush tank, the level drop will only be 1 to

2 in. 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 1 to

2 in., reverse the flow.

8. Repeat this procedure until all air is purged.

9. Restore power.

Antifreeze may be added before, during, or after the flush-

ing 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

heating 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 40 to 50 psig for winter months or

15 to 20 psig 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 31.

Antifreeze —

In areas where entering loop temperatures

drop below 40 F or where piping will be routed through areas

subject to freezing, antifreeze is needed.

Alcohols and glycols are commonly used as antifreeze

agents. Freeze protection should be maintained to 15 F below

the lowest expected entering loop temperature. For example, if

the lowest expected entering loop temperature is 30 F, the leav-

ing loop temperature would be 22 to 25 F. Therefore, the freeze

protection should be at 15 F (30 F – 15 F = 15 F).

50PSH, PSV, PSD

UNIT SIZE

WATER

FLOW
(GPM)

WATER TEMPERATURE (F)

30 F

50 F

70 F

90 F

Pressure Drop (psi)

006

1.0

0.3

0.3

0.2

0.2

1.5

1.6

1.4

1.2

1.0

2.0

3.0

2.6

2.2

1.8

009

1.4

0.8

0.7

0.6

0.6

2.1

1.5

1.4

1.2

1.1

2.8

2.7

2.4

2.2

1.9

012

1.8

0.6

0.5

0.4

0.3

2.6

2.1

1.9

1.6

1.4

3.5

3.8

3.4

3.0

2.6

018

2.8

0.7

0.5

0.3

0.2

4.1

2.1

1.7

1.4

1.1

5.5

3.5

2.8

2.4

2.0

024

4.0

1.5

1.3

1.1

1.0

6.0

3.1

2.6

2.3

2.1

8.0

5.1

4.3

3.8

3.4

030

4.0

1.5

1.3

1.1

1.0

6.0

3.1

2.6

2.3

2.1

8.0

5.1

4.3

3.8

3.4

036

4.5

1.7

1.3

1.1

0.9

6.8

3.3

3.1

2.9

2.6

9.0

5.7

5.2

4.8

4.4

042

5.5

1.1

0.9

0.8

0.7

8.3

2.2

2.1

2.0

1.8

11.0

3.9

3.6

3.2

3.1

048

6.0

1.3

1.1

1.0

0.9

9.0

2.6

2.5

2.3

2.2

12.0

4.5

4.2

3.8

3.5

060

7.5

0.6

0.4

0.3

0.2

11.3

2.3

2.1

2.0

1.8

15.0

4.8

4.3

3.9

3.5

070

8.3

2.4

2.0

1.7

1.6

12.4

5.2

4.5

4.0

3.8

16.5

8.0

7.0

6.3

6.0

WARNING

To avoid possible injury or death due to electrical shock,

open the power supply disconnect switch and secure it in

an open position before flushing system.

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