Carrier 50PSW036-360 specifications Heat Exchanger Pressure Drop, Unit Size

Table 7 — Heat Exchanger Pressure Drop

UNIT SIZES 036-120

50PSW	L/s		PRESSURE DROP (kPa)
UNIT SIZE		–1 C		10 C	21 C	32 C
		Source/Outdoor Coax
036	0.28	11.7		9.0	6.9	5.5
	0.43	28.3		23.4	19.3	16.5
	0.57	49.0		41.4	35.2	31.0
060	0.47	10.3		9.0	17.2	14.5
	0.71	27.6		23.4	47.6	42.1
	0.95	47.6		42.8	88.3	80.0
120	0.95	11.7		9.7	8.3	6.2
	1.42	30.3		26.2	22.8	18.6
	1.89	52.4		46.9	42.1	34.5
		Load/Outdoor Coax
036	0.28	—		4.1	3.4	2.1
	0.43	—		9.7	9.0	7.6
	0.57	—		18.0	16.5	15.2
060	0.47	—		9.7	9.0	8.3
	0.71	—		24.1	22.1	20.7
	0.95	—		42.8	40.0	37.9
120	0.95	—		11.0	9.7	2.1
	1.42	—		26.2	24.1	22.8
	1.89	—		46.9	44.1	41.1
		UNIT SIZES 180,360
50PSW	L/s		PRESSURE DROP (kPa)
UNIT SIZE		0 C		10 C	20 C	30 C
		Source/Outdoor Coax
180	1.10	4.82		2.76	1.72	0.88
	1.67	17.92		11.72	11.38	9.47
	2.21	32.40		22.75	21.37	19.30
360	2.21	11.03		8.27	7.22	6.29
	3.34	26.88		24.82	23.10	21.29
	4.42	48.95		44.82	41.36	38.47

NOTE: Bold values indicate use of antifreeze is required.

Cleaning and Flushing — Cleaning and flushing of the piping system is the single most important step to ensure proper start-up and continued efficient operation of the system.

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. Install lockout tag.

Follow the instructions below to properly clean and flush the system:

1.Verify electrical power to the unit is disconnected and lockout tag installed.

2.Install the system with the supply hose connected directly to the return riser valve. Use a single length of flexible hose.

3.Open all air vents. Fill the system with the water. DO NOT allow system to overflow. Bleed all air from the system. Pressurize and check the system for leaks and re- pair appropriately.

4.Verify all strainers are in place. Start the pumps, and sys- tematically check each vent to ensure all air is bled from the system.

5.Verify make-up water is available. Adjust make-up water appropriately to replace the air which was bled from the system. Check and adjust the water/air level in the expan- sion tank.

6.Raise the loop temperature to approximately 29.4 C. Open the drain at the lowest point in the system. Adjust the make-up water replacement rate to equal the rate of bleed.

7.Refill the system and add trisodium phosphate in a pro- portion of approximately 0.5 kg per 750 L of water (or other equivalent approved cleaning agent).

CAUTION

To avoid possible damage to a plastic (PVC) piping sys- tem, do not allow temperatures to exceed 43.3 C.

Raise the loop temperature to 37.8 C. Circulate the solu- tion for a minimum of 8 to 24 hours. At the end of this period, shut off the circulating pump and drain the solu- tion. Repeat system cleaning if desired.

8.When the cleaning process is complete, remove the short- circuited hose. Reconnect the hoses to the proper supply, and return the connections to each of the units. Refill the system and bleed off all air.

9.Test the system pH with litmus paper. The system water should be slightly alkaline (pH of 7.5 to 8.5). Add chemi- cals, as appropriate, to maintain acidity levels.

10.When the system is successfully cleaned, flushed, refilled and bled, restore power.

11.Check the main system panels, safety cutouts and alarms. Set the controls to properly maintain loop temperatures.

CAUTION

DO NOT use “Stop Leak” or any similar chemical agent in this system. Addition of these chemicals to the loop water will foul the system and inhibit unit operation.

Antifreeze — In areas where entering loop temperatures drop below 4.4 C 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 8.3° C below the lowest expected entering loop temperature. For example, if the lowest expected entering loop temperature is –1.1 C, the leaving loop temperature would be –5.6 to –3.9 C. Therefore, the freeze protection should be at –9.4 C (–1.1 C – 8.3 C = –9.4 C).

IMPORTANT: All alcohols should be pre-mixed and pumped from a reservoir outside of the building or introduced under water level to prevent alcohols from fuming.

Calculate the total volume of fluid in the piping system. See Table 8. Use the percentage by volume in Table 9 to determine the amount of antifreeze to use. Antifreeze concentration should be checked from a well mixed sample using a hydrome- ter to measure specific gravity.

FREEZE PROTECTION SELECTION — The –1.1 C FP1 factory setting (water) should be used to avoid freeze damage to the unit.

Once antifreeze is selected, the JW3 jumper (FP1) should be clipped on the control to select the low temperature (anti- freeze –12.2 C) set point to avoid nuisance faults.

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