Carrier Ecologic Series 3 Controls, Start-up, Operation, Service, And Troubleshooting

Also see for Ecologic 30GX080 Series: User manual Controls, start-up, operation, service, and troubleshooting

36 thermistors, and up to 10 transducers. A remote enhanceddisplay is available as an accessory.MAJOR SYSTEM COMPONENTSProcessor Module (PSIO-1) — This module is anupgrade to the original PSIO (8088) module, with superiorelectrical noise immunity capability. It contains the operatingsoftware and controls the operation of the machine. It has 12input channels and 6 output channels.The PSIO-1 continuously monitors input/output channel in-formation received from all the modules and controls all outputsignals for all output channels. It also controls the relays on thesix-pack relay board. The processor module also controls theEXD driver module, commanding it to open or close eachEXD in order to maintain the proper cooler level. Informationis transmitted between the processor module, CPM modules,the EXD driver module, and the HSIO-II standard displaymodule through a 3-wire communications bus called COMM3.The remote enhanced display (accessory) is connected to thePSIO-1 module through a 3-wire communications bus, butuses a different communication bus called COMM1. TheCOMM1 bus is also used to communicate to other CCN(Carrier Comfort Network) devices when the unit is installed ina network application.DSIO-HV Relay Module — The DSIO-HV module has4 inputs and 8 outputs and is installed on 30GX units only. Themodule communicates the status of the inputs with the PSIO-1module and operates the oil heater, outdoor fan, and minimumload control outputs.Electronic Expansion Device Module — Theelectronic expansion device module has 4 inputs and 2 outputs.It receives signals from the PSIO-1 module and operates theelectronic expansion devices. The electronic expansion devicemodule also sends the PSIO-1 module the status of its 4 inputchannels.Compressor Protection Module (CPM) — Thecompressor protection module monitors the high pressureswitch status, running current, and motor temperature for eachcompressor. Each CPM controls up to 2 compressors. TheCPM also controls the motor cooling solenoid, oil solenoid,and contactor outputs. A pre-punched configuration header foreach compressor determines the must trip amps setting. EachCPM sends the PSIO-1 each compressor’s motor temperature,relay status, and running current as a percentage of the musttrip amps value. The CPM also communicates any alarm con-ditions as the feedback value.PSIO-2 (8052) Module — This module is used as an in-put/output module only, as there is no unit software loaded inthe module. This module has 12 input channels and 6 outputchannels.Keypad and Display Module (Also CalledHSIO-II) — This device consists of a keypad with 8 functionkeys, 4 operative keys, 12 numeric keys, and a 2-line24-character alphanumeric LCD (liquid crystal display). Keyusage is explained in the Accessing Functions and Subfunc-tions section on page 15.Control (LOR) Switch — Control of the chiller is de-fined by the position of the LOCAL/OFF/REMOTE (LOR)switch. This is a 3-position manual switch that allows the chill-er to be put under the control of its own controls (LOCAL),manually stopped (OFF), or controlled through a set of remotecontacts (REMOTE). This switch is different than the switchthat is used in the Flotronic™ II controls configuration. TheCCN control is enabled through the HSIO-II. The switch al-lows unit operation as shown in Table 1.In the LOCAL position, the chiller is allowed to operate andrespond to the scheduling configuration, CCN configuration,and set point data. In the remote position, the unit operates sim-ilarly to the LOCAL position, except the remote contacts mustbe closed for the unit to operate.Table 1 — Unit Mode from LOR Switchand CCN StateLEGENDNOTE: If the unit is configured for a clock, then the unit is under clock control if it is in anON mode.OPERATION DATAElectronic Expansion Device (EXD) — The micro-processor controls the EXD through the EXD driver module.The EXD will either be an EXV (electronic expansion valve) oran economizer. Inside both these devices is a linear actuator step-per motor.EXV OPERATION — High-pressure liquid refrigerant en-ters the valve through the bottom. A series of calibrated slotsare located inside the orifice assembly. As refrigerant passesthrough the orifice, the pressure drops and the refrigerantchanges to a 2-phase condition (liquid and vapor). To controlrefrigerant flow for different operating conditions, the sleevemoves up and down over the orifice, thereby changing orificesize. The sleeve is moved by a linear stepper motor. The step-per motor moves in increments and is controlled directly by theprocessor module. As the stepper motor rotates, motion istransferred into linear movement by the lead screw. Throughthe stepper motor and lead screw, 1500 discrete steps of motionare obtained. The large number of steps and long stroke resultin very accurate control of refrigerant flow.Each circuit has a liquid level sensor mounted vertically inthe top of the cooler shell. The level sensor consists of a smallelectric resistance heater and 3 thermistors wired in series, po-sitioned at different heights inside the body of the well. Theheater is designed so that the thermistors read approximately200 F (93.3 C) in dry air. As the refrigerant level rises (falls) inthe cooler, the resistance of the closest thermistor(s) will in-crease (decrease) as it is cooled by the rising liquid refrigerant(heated by the heater). This large resistance difference allowsthe control to accurately maintain a specified level.The level sensor monitors the refrigerant liquid level in thecooler and sends this information to the PSIO-1. At initial start-up, the EXV position is at zero. After that, the microprocessorkeeps accurate track of the valve position in order to use this in-formation as input for the other control functions. The proces-sor does this by initializing the EXVs at start-up. The processorsends out enough closing pulses to the valve to move it fromfully open to fully closed, then resets the position counter to ze-ro. From this point on, until the next initialization, the proces-sor counts the total number of open and closed steps it has sentto each valve.SWITCHPOSITION REMOTECONTACTS CCNCONFIGURATION CCNSTATE UNITMODELOCAL NRDISABLE NR LOCAL ONENABLE RUN CCN ONSTOP CCN OFFOFF NR NR NR LOCAL OFFREMOTEOPEN NR NR LOCAL OFFCLOSEDDISABLE NR LOCAL ONENABLE RUN CCN ONSTOP CCN OFFCCN — Carrier Comfort NetworkNR — Input Not Read by Processor