Carrier 17 Start Up & Operation Manual

Contents

OPERATING INSTRUCTIONSOperator Duties1. Become familiar with refrigeration machine and relatedequipment before operating the machine.2. Prepare the system for start-up, start and stop the ma-chine, and place the system in a shutdown condition.3. Maintain a log of operating conditions and document anyabnormal readings.4. Inspect the equipment, make routine adjustments, and per-form a control test. Maintain the proper oil and refriger-ant levels.5. Protect the system from damage during shutdownperiods.6. Maintain the set point, time schedules, and other PICfunctions.Prepare the Machine for Start-Up — Follow thesteps described in the Initial Start-Up section, page 58.To Start the Machine1. Start the water pumps, if they are not automatic.2. On the LID default screen, press the LOCAL orCCN softkey to start the system. If the machine is inthe OCCUPIED mode, and the 3- and 15-minute starttimers have expired, the start sequence will start. Followthe procedure described in the Start-Up/Shutdown/Recycle section, page 45.Check the Running System — After the compres-sor starts, the operator should monitor the LID display andobserve the parameters for normal operating conditions:1. The oil reservoir temperature should be above 150 F(66 C) or refrigerant temperature plus 70° F (38° C) dur-ing shutdown, and above 125 F (52 C) during compres-sor operation.2. The bearing oil temperature accessed on the Status01 LIDscreen should be 150 to 200 F (65 to 93 C). If the bearingtemperature reads more than 210 F (99 C) with the oilpump running, stop the machine and determine the causeof the high temperature. Do not restart the machine untilcorrected.3. The oil level should be visible in the lower sight glasswhen the compressor is running.At shutdown, oil level should be halfway in the lowersight glass.4. The oil pressure should be between 18 and 30 psi (124 to207 kPa) differential, as seen on the LID defaultscreen. Typically the reading will be 18 to 25 psi (124 to172 kPa) at initial start-up.5. The moisture indicating sight glass on the refrigerantmotor cooling line (Fig. 8) should indicate refrigerant flowand a dry condition.6. The condenser pressure and temperature varies with themachine design conditions. Typically the pressure will rangebetween 100 and 210 psig (690 to 1450 kPa) with a cor-responding temperature range of 60 to 105 F (15 to41 C). The condenser entering water temperature shouldbe controlled below the specified design entering watertemperature to save on compressor kilowatt require-ments. The leaving condenser water temperature shouldbe at least 20° F (11° C) above leaving chilled watertemperature.7. Cooler pressure and temperature also will vary with thedesign conditions. Typical pressure range will be be-tween 60 and 80 psig (410 and 550 kPa), with tempera-ture ranging between 34 and 45 F (1 and 8 C).8. The compressor may operate at full capacity for a shorttime after the pulldown ramping has ended, even thoughthe building load is small. The active electrical demandsetting can be overridden to limit the compressor IkW, orthe pulldown rate can be decreased to avoid a high de-mand charge for the short period of high demandoperation. Pulldown rate can be based on kW rate or tem-perature rate. It is accessed on the Equipment Configu-ration menu Config screen (Table 2, Example 5).9. On open-drive machines, the oil pump will be energizedonce every 12 hours during shutdown periods to ensurethat the shaft seal is filled with oil.To Stop the Machine1. The occupancy schedule will start and stop the machineautomatically once the time schedule is set up.2. By pressing the Stop button for one second, the alarmlight will blink once to confirm that the button has beenpressed, then the compressor will follow the normal shut-down sequence as described in the Controls section. Themachine will not restart until the CCN or LOCAL soft-key is pressed. The machine is now in the OFF mode.NOTE: If the machine fails to stop, in addition to action thatthe PIC will initiate, the operator should close the guide vanesby overriding the guide vane target to zero to reduce ma-chine load; then by opening the main disconnect. Do not at-tempt to stop the machine by opening an isolating knife switch.High intensity arcing may occur. Do not restart the machineuntil the problem is diagnosed and corrected.After Limited Shutdown — No special preparationsshould be necessary. Follow the regular preliminary checksand starting procedures. Control Power must be maintainedin order to keep oil temperature hot and all control safetiesoperational. The oil pump on open-drive machines will op-erate occasionally to keep the contact seal filled with oil toprevent refrigerant loss.61