Carrier 17 Start Up & Operation Manual

Contents

Table 4 — Capacity OverridesOVERRIDECAPACITYCONTROLFIRST STAGE SETPOINT SECOND STAGESETPOINTOVERRIDETERMINATIONView/Modifyon LID Screen Default Value Configurable Range Value ValueHIGH CONDENSERPRESSURE EquipmentService1 125 psig(862 kPa) 90 to 200 psig(620 to 1379 kPa).OverrideSet Point+ 4 psid (28 kPad),OverrideSet PointHIGH MOTORTEMPERATURE*EquipmentService1.200 F(93.3 C)150 to 200 F(66 to 93 C).OverrideSet Point+10° F (6° C),OverrideSet PointLOW REFRIGERANTTEMPERATURE(Refrigerant OverrideDelta Temperature)EquipmentService1 ,3° F (1.6° C)(Above Trippoint) 2° to 5° F(1° to 3° C)<Trippoint+ OverrideDT –1° F(0.56° C).Trippoint+ OverrideDT +2° F(1.2° C)HIGH COMPRESSORLIFT(Surge Prevention)EquipmentService1Min: T1 — 1.5° F(0.8° C)P1 — 50 psid(345 kPad)Max: T2 — 10° F(5.6° C)P2 — 85 psid(586 kPad)0.5° to 15° F(0.3° to 8.3° C)30 to 170 psid(207 to1172 kPad)0.5° to 15° F(0.3° to 8.3° C)30 to 170 psid(207 to 1172 kPad)NoneWithinLift LimitsPlus Surge/HGBPDeadbandSettingMANUALGUIDE VANETARGETControlAlgorithmMaint01Automatic 0 to 100% None Release ofManualControlMOTOR LOAD —ACTIVEDEMAND LIMIT Status01 100% 40 to 100% >5% ofSet Point2% LowerThanSet PointLEGENDP1 — Minimum Pressure LoadP2 — Maximum Pressure LoadT1 — Minimum Temperature LoadT2 — Maximum Temperature Load*Not available on open drive machines.Oil Sump Temperature Control — The oil sump tem-perature control is regulated by the PIC which uses the oilheater relay when the machine is shut down.As part of the pre-start checks executed by the controls,oil sump temperature is compared against evaporator refrig-erant temperature. If the difference between these 2 tem-peratures is 50 F (27.8 C) or less, the start-up will be delayeduntil the oil temperature is 50 F (27.8 C) or more. Once thistemperature is confirmed, the start-up continues.The oil heater relay is energized whenever the chiller com-pressor is off and the oil sump temperature is less than150 F (65.6 C) or the oil sump temperature is less than thecooler refrigerant temperature plus 70° F (39° C). The oilheater is turned off when the oil sump temperature is either1) more than 160 F (71.1 C); or 2) the oil sump temperatureis more than 155 F (68.3 C) and more than the coolerrefrigerant temperature plus 75° F (41.6° C). The oil heateris always off during start-up or when the compressor isrunning.When a power failure to the PSIO module has occurredfor more than 3 hours (i.e., initial start-up), the compressorguide vane opening will be slowed down to prevent exces-sive oil foaming that may result from refrigerant migrationinto the oil sump during the power failure. The vane openingwill be slowed to a value of 2° F (1.1° C) per minute withtemperature ramp loading.Oil Cooler — The oil must be cooled when the compres-sor is running.EX Compressors: This is accomplished through a small, plate-type heat exchanger. The heat exchanger uses liquid con-denser refrigerant as the cooling liquid. A refrigerant ther-mostatic expansion valve (TXV) regulates refrigerant flowto control oil temperature entering the bearings. There is al-ways a flow of refrigerant bypassing the TXV. The bulb forthe expansion valve is strapped to the oil supply line leavingthe heat exchanger and the valve is set to maintain 110 F(43 C).NOTE: The expansion valve is not adjustable. Oil sump tem-perature may be at a lower temperature.FA Compressors: The oil cooler is a water cooled, tube-in-shell type heat exchanger. A plug valve is manually set tomaintain proper temperatures. Set the valve to maintain145 F (63 C) oil sump temperatures while the compressor isrunning.Remote Start/Stop Controls — A remote device, suchas a timeclock which uses a set of contacts, may be used tostart and stop the machine. However, the device should notbe programmed to start and stop the machine in excess of 2or 3 times every 12 hours. If more than 8 starts in 12 hoursoccur, then an Excessive Starts alarm is displayed, prevent-ing the machine from starting. The operator must reset thealarm at the LID in order to override the starts counter andstart the machine. If Automatic Restart After a Power Fail-ure is not activated when a power failure occurs, and theremote contact is closed, the machine will indicate an alarmbecause of the loss of voltage.The contacts for Remote Start are wired into the starter atterminal strip TB5, terminals 8A and 8B. See the certifieddrawings for further details on contact ratings. The contactsmust be dry (no power).Spare Safety Inputs — Normally closed (NC) digitalinputs for additional field-supplied safeties may be wired tothe spare protective limits input channel in place of the factory-installed jumper. (Wire multiple inputs in series.) The open-ing of any contact will result in a safety shutdown and LIDdisplay. Refer to the certified drawings for safety contactratings.Analog temperature sensors may also be added to the op-tions modules, if installed. These may be programmed to causean alert on the CCN network, but will not shut the machinedown.Spare Alarm Contacts — Two spare sets of alarm con-tacts are provided within the starter. The contact ratings areprovided in the certified drawings. The contacts are locatedon terminal strip TB6, terminals 5A and 5B, and terminals5C and 5D.38