Carrier XRV General Maintenance, Test After Service, Repair, or Major Leak - If, on manually

2. Evacuate the refrigerant gas from the chiller condenser vessel.

a. Access the PUMPDOWN LOCKOUT function accessed from the CVC/ICVC CONTROL TEST table to turn on the chiller water pumps. Turn the chiller water pumps on manually if they are not controlled by the PIC II.

b.

Close pumpout unit valves 3 and 4; open valves 2

and 5.

VALVE

1a

1b

2

3

4

5

8

11

12

13

14

CONDITION

C

C

C

C

C

C

C

c.

Turn on the pumpout condenser water.

d.

Run the pumpout compressor until the chiller

condenser pressure reaches 18 in. Hg vac (40 kPa

abs.). Monitor pressure at the CVC/ICVC and at

refrigerant gages.

e.

Close valve 1b.

f.

Turn off the pumpout compressor.

g.

Close valves 1a, 2, and 5.

VALVE

1a

1b

2

3

4

5

8

11

12

13

14

CONDITION

C

C

C

C

C

C

C

C

C

C

C

h.

Turn off the pumpout condenser water.

i.

Proceed to the PUMPDOWN LOCKOUT test

from the CVC/ICVC CONTROL TEST table to

turn off the chiller water pumps and lock out the

chiller compressor. Turn off the chiller water pumps manually if they are not controlled by the

PIC II.

RETURN CHILLER TO NORMAL OPERATING CONDITIONS

1.	Ensure vessel that was opened has been evacuated.
2.	Access the TERMINATE LOCKOUT function CVC/
	ICVC from the CONTROL TEST table to view vessel
	pressures and turn on chiller water pumps. If the chiller
	water pumps are not controlled by the PIC II, turn them
	on manually.
3.	Open valves 1a, 1b, and 3.
		VALVE		1a	1b	2		3		4	5	8	11	12	13	14
		CONDITION				C				C	C	C	C	C	C	C
4.	Slowly open valve 5, gradually increasing pressure in the
	evacuated vessel to 35 psig (141 kPa). Feed refrigerant
	slowly to prevent tube freeze up.
5.	Leak test to ensure vessel integrity.
6.	Open valve 5 fully.
		VALVE		1a	1b	2		3		4	5	8	11	12	13	14
		CONDITION				C				C		C	C	C	C	C
7.	Open valve 11 to equalize the liquid refrigerant level be-
	tween the vessels.
8.	Close valves 1a, 1b, 3, and 5.
9.	Open isolation valves 12, 13, and 14 (if present).
		VALVE		1a	1b	2		3		4	5	8	11	12	13	14
		CONDITION	C		C	C	C		C		C	C
10.	Proceed to the TERMINATE LOCKOUT screen (access-
	ed from the CONTROL TEST table) to turn off the water
	pumps and enable the chiller compressor for start-up. If

the chiller water pumps are not controlled by the PIC II, turn them off manually.

GENERAL MAINTENANCE

Refrigerant Properties — The standard refrigerant for the 19XR chiller is HFC-134a. At normal atmospheric pres- sure, HFC-134a will boil at –14 F (–25 C) and must, therefore, be kept in pressurized containers or storage tanks. The refriger- ant is practically odorless when mixed with air and is noncom- bustible at atmospheric pressure. Read the Material Safety Data Sheet and the latest ASHRAE Safety Guide for Mechani- cal Refrigeration to learn more about safe handling of this refrigerant.

HFC-134a will dissolve oil and some nonmetallic materi- als, dry the skin, and, in heavy concentrations, may dis- place enough oxygen to cause asphyxiation. When handling this refrigerant, protect the hands and eyes and avoid breathing fumes.

Adding Refrigerant — Follow the procedures de- scribed in Trim Refrigerant Charge section, page 72.

Always use the compressor pumpdown function in the Control Test table to turn on the cooler pump and lock out the compressor when transferring refrigerant. Liquid refrig- erant may flash into a gas and cause possible freeze-up when the chiller pressure is below 30 psig (207 kPa) for HFC-134a.

Removing Refrigerant — If the optional pumpout sys- tem is used, the 19XR refrigerant charge may be transferred to a pumpout storage tank or to the chiller condenser or cooler vessels. Follow the procedures in the Pumpout and Refrigerant Transfer Procedures section when transferring refrigerant from one vessel to another.

Adjusting the Refrigerant Charge — If the addi- tion or removal of refrigerant is required to improve chiller per- formance, follow the procedures given under the Trim Refrig- erant Charge section, page 72.

Refrigerant Leak Testing — Because HFC-134a is above atmospheric pressure at room temperature, leak testing can be performed with refrigerant in the chiller. Use an elec- tronic halide leak detector, soap bubble solution, or ultrasonic leak detector. Ensure that the room is well ventilated and free from concentration of refrigerant to keep false readings to a minimum. Before making any necessary repairs to a leak, transfer all refrigerant from the leaking vessel.

Leak Rate — It is recommended by ASHRAE that chillers be taken off line immediately and repaired if the refrigerant leak rate for the entire chiller is more than 10% of the operating refrigerant charge per year.

In addition, Carrier recommends that leaks totalling less than the above rate but more than a rate of 0.1% of the total charge per year should be repaired during annual maintenance or whenever the refrigerant is transferred for other service work.

Test After Service, Repair, or Major Leak — If

all the refrigerant has been lost or if the chiller has been opened for service, the chiller or the affected vessels must be pressure tested and leak tested. Refer to the Leak Test Chiller section to perform a leak test.

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