Carrier 17 Start Up & Operation Manual

Contents

PIC System Components — The Product IntegratedControl (PIC) is the control system on the machine. SeeTable 1. The PIC controls the operation of the machine bymonitoring all operating conditions. The PIC can diagnosea problem and let the operator know what the problem is andwhat to check. It promptly positions the guide vanes to main-tain leaving chilled water temperature. It can interface withauxiliary equipment such as pumps and cooling tower fansto turn them on only when required. It continually checks allsafeties to prevent any unsafe operating condition. It alsoregulates the oil heater while the compressor is off, and thehot gas bypass valve, if installed.The PIC can be interfaced with the Carrier ComfortNetwork (CCN) if desired. It can communicate with otherPIC-equipped chillers and other CCN devices.The PIC consists of 3 modules housed inside the 3 majorcomponents. The component names and the control voltagecontained in each component are listed below (also seeTable 1):• control center— all extra low-voltage wiring (24 v or less)• power panel— 115 v control voltage— up to 600 v for oil pump power• starter cabinet— machine power wiring (per job requirement)Table 1 — Major PIC Components andPanel Locations*PIC COMPONENT PANELLOCATIONProcessor Sensor Input/Output Module (PSIO) Control CenterStarter Management Module (SMM) Starter CabinetLocal Interface Device (LID) Control Center6-Pack Relay Board Control Center8-Input Modules (Optional) Control CenterOil Differential Pressure/Power SupplyModule Control CenterOil Heater Contactor (1C) Power PanelOil Pump Contactor (2C) Power PanelHot Gas Bypass Relay (3C) (Optional) Power PanelControl Transformers (T1-T4) Power PanelControl and Oil Heater Voltage Selector (S1) Power PanelTemperature Sensors See Fig. 10Pressure Transducers See Fig. 11*See Fig. 7-13.PROCESSOR MODULE (PSIO) — This module containsall of the operating software needed to control the machine.The open-drive machines use a different software packagewithin the PSIO than the hermetic machines. There are alsocontrol hardware differences between the two types of ma-chines. The 19EX uses 3 pressure transducers and 8 ther-mistors to sense pressures and temperatures. The 17EX uses4 pressure transducers and 7 thermistors to sense pressuresand temperatures.These inputs are connected to the PSIO module. The PSIOalso provides outputs to the: guide vane actuator; oil pump;oil heater; hot gas bypass (optional); motor cooling sole-noid; and alarm contact. The PSIO communicates with theLID, the SMM, and the optional 8-input modules for userinterface and starter management.STARTER MANAGEMENT MODULE (SMM) — This mod-ule is located within the starter cabinet. This module ini-tiates PSIO commands for starter functions such as start/stop of the compressor, start/stop of the condenser and chilledwater pumps, start/stop of the tower fan, spare alarm con-tacts, and the shunt trip. The SMM monitors starter inputssuch as flow switches, line voltage, remote start contact, sparesafety, condenser high pressure, oil pump interlock, motorcurrent signal, starter 1M and run contacts, and kW trans-ducer input (optional). The SMM contains logic capable ofsafely shutting down the machine if communication withthe PSIO is lost.LOCAL INTERFACE DEVICE (LID) — The LID is mountedto the control center and allows the operator to interface withthe PSIO or other CCN devices. It is the input center for alllocal machine set points, schedules, set-up functions, and op-tions. The LID has a STOP button, an alarm light, 4 buttonsfor logic inputs, and a display. The function of the 4 buttonsor ‘‘softkeys’’ are menu driven and are shown on the displaydirectly above the key.6-PACK RELAY BOARD — This device is a cluster of6 pilot relays located in the control center. It is energized bythe PSIO for the oil pump, oil heater, alarm, optional hot gasbypass relay, and motor cooling solenoid (19EX machines)on auxiliary oil pump (17EX machines).8-INPUT MODULES — One optional module is factory in-stalled in the control center panel when ordered. There canbe up to 2 of these modules per chiller with 8 spare inputseach. They are used whenever chilled water reset, demandreset, or reading a spare sensor is required. The sensors or 4to 20 mA signals are field-installed.The spare temperature sensors must have the sametemperature/resistance curve as the other temperature sen-sors on this unit. These sensors are rated 5,000 ohm at 75 F(25 C).OIL HEATER CONTACTOR (1C) — This contactor is lo-cated in the power panel and operates the heater at 115 v. Itis controlled by the PIC to maintain oil temperature duringmachine shutdown.OIL PUMP CONTACTOR (2C) — This contactor is locatedin the power panel. It operates all 200 to 575-v oilpumps. The PIC energizes the contactor to turn on the oilpump as necessary.HOT GAS BYPASS CONTACTOR RELAY (3C)(Optional) — This relay, located in the power panel, con-trols the opening of the hot gas bypass valve. The PIC en-ergizes the relay during low load, high lift conditions.OIL AUXILIARY RELAY (4C) — This relay, supplied onlywith open-drive machines, opens the oil cooler solenoid valveand interlocks the oil pump with the compressor.CONTROL TRANSFORMERS (T1-T4) — These trans-formers are located in the power panel and convert incom-ing control voltage to either 21 vac power for the PSIO moduleand options modules, or 24 vac power for 3 power panelcontactor relays and a control solenoid valve.CONTROLAND OIL HEATER VOLTAGE SELECTOR (S1)— It is necessary to use 115 v incoming control power in thepower panel. The switch must be set to the 115-v position.OIL DIFFERENTIAL PRESSURE/POWER SUPPLYMODULE — This module, which is located in the controlcenter, provides 5 vdc power for the transducers and LIDbacklight.On open-drive machines, this module outputs the differ-ence between two pressure transducer input signals. The mod-ule subtracts oil supply pressure from transmission sumppressure and outputs the difference as an oil differential pres-sure signal to the PSIO. The PSIO converts this signal todifferential oil pressure. To calibrate this reading, refer tothe Troubleshooting, Checking Pressure Transducers.14