Carrier Essential Maintenance and Control Functions for 19XR Chillers

Check Optional Pumpout System Controls and Compressor — Controls include an on/off switch, a 3-amp fuse, the compressor overloads, an internal thermostat, a compressor contactor, and a refrigerant high pressure cutout. The high pressure cutout is factory set to open at 161 psig (1110 kPa) and reset at 130 psig (896 kPa). Ensure the water- cooled condenser has been connected. Loosen the compressor holddown bolts to allow free spring travel. Open the compres- sor suction and discharge the service valves. Ensure oil is visi- ble in the compressor sight glass. Add oil if necessary.

See the Pumpout and Refrigerant Transfer Procedures and Optional Pumpout System Maintenance sections, pages 67 and 75, for details on the transfer of refrigerant, oil specifications, etc.

Table 9 — Control Test Menu Functions

TESTS TO BE	DEVICES TESTED
PERFORMED
1. CCM Thermistors	Entering Chilled Water
	Evaporator Refrigerant Tempera-
	ture (ICVC only)
	Leaving Chilled Water
	Entering Condenser Water
	Leaving Condenser Water
	Remote Reset Sensor
	Comp Discharge Temp
	Oil Sump Temp
	Comp Motor Winding Temp
	Space Temperature 1
	Space Temperature 2
2. CCM Pressure	Evaporator Pressure
Transducers	Condenser Pressure
	Oil Pump Delta P
	Condenser Water Delta P
	Transducer Voltage Ref
3. Pumps	Chilled Water — Confirm pressure
	Condenser Water — Confirm
	Delta P
4. Discrete Outputs	Oil Heater Relay
	Hot Gas Bypass Relay
	Tower Fan Relay Low
	Tower Fan Relay High
	Alarm Relay
	Shunt Trip Relay
5. Guide Vane Actuator	Open/Close
6. Diffuser Actuator	Open/Close

7.Pumpdown Lockout When using pumpdown/lockout, observe freeze up precautions when removing charge:

	Instructs operator which valves to
	close and when.
	Starts chilled water and condenser
	water pumps and confirms flows.
	Monitors
	Evaporator pressure
	Condenser pressure
	Evaporator temperature during
	pumpout procedures
	Turns pumps off after pumpdown.
	Locks out compressor.
8 Terminate Lockout	Starts pumps and monitors flows.
	Instructs operator which valves to
	open and when.
	Monitors
	Evaporator pressure
	Condenser pressure
	Evaporator temperature during
	charging process
	Terminates compressor lockout.

High Altitude Locations — Because the chiller is ini- tially calibrated at sea level, it is necessary to recalibrate the pressure transducers if the chiller has been moved to a high alti- tude location. See the calibration procedure in the Trouble- shooting Guide section.

Charge Refrigerant into Chiller

The transfer, addition, or removal of refrigerant in spring isolated chillers may place severe stress on external piping if springs have not been blocked in both up and down directions.

Always operate the condenser and chilled water pumps during charging operations to prevent freeze-ups.

The standard 19XR chiller is shipped with the refrigerant already charged in the vessels. However, the 19XR may be or- dered with a nitrogen holding charge of 15 psig (103 kPa). Evacuate the nitrogen from the entire chiller, and charge the chiller from refrigerant cylinders.

CHILLER EQUALIZATION WITHOUT A PUMPOUT UNIT

When equalizing refrigerant pressure on the 19XR chiller after service work or during the initial chiller start-up, do not use the discharge isolation valve to equalize. Either the motor cooling isolation valve or the charging hose (con- nected between the pumpout valves on top of the cooler and condenser) should be used as the equalization valve.

To equalize the pressure differential on a refrigerant isolated 19XR chiller, use the terminate lockout function of the CON- TROL TEST on the SERVICE menu. This helps to turn on pumps and advises the operator on proper procedures.

The following steps describe how to equalize refrigerant pressure in an isolated 19XR chiller without a pumpout unit.

1.Access terminate lockout function on the CONTROL TEST screen.

2.IMPORTANT: Turn on the chilled water and con- denser water pumps to prevent freezing.

3.Slowly open the refrigerant cooling isolation valve. The chiller cooler and condenser pressures will gradually equalize. This process takes approximately 15 minutes.

4.Once the pressures have equalized, the cooler isolation valve, the condenser isolation valve, and the hot gas isola- tion valve may now be opened. Refer to Fig. 29 and 30, for the location of the valves.

Whenever turning the discharge isolation valve, be sure to reattach the valve locking device. This prevents the valve from opening or closing during service work or during chiller operation.

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