Carrier XRV Refrigerator User Manual

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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.

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.

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.

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.

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).

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.

Adding Refrigerant —

Follow the procedures de-

scribed in Trim Refrigerant Charge section, page 72.

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 —

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.