Carrier 48HC 04-28 Controls, Start-up, Operation And Troubleshooting

Also see for /50HC 04-28: Manual

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Carrier 48HC 04-28 Controls, Start-up, Operation And Troubleshooting Manual pdf 67 page image

67determine which one is having the problem. In test mode runthe components individually to determine which is causing theproblem. If the Shut Down on fan failure configuration is set toYes (Configuration →OAU →OAU.F = Yes), the ERV willshutdown with this alarm active. If set to no, the ERV will con-tinue to run as if the alarm did not occur, outside air CFM, ex-haust CFM, or pre-conditions might not be achievable if a mo-tor fails. The two classes of motor status are explained below.Intake and Exhaust Motor StatusIf any one of the ERV’s outside or exhaust motors detects aproblem, it will close its build in normally open alarm contact,which will be seen as 24vac at EXCB J8-3. The EXCB’s D18LED will be turn on and the OAU Motor Failure Alarm pointwill be turned to on (Operating Modes →OAU →ALM.1 =On). This alarm will automatically reset when the motor opensits alarm relay. This alarm is tripped by one of the following:phase loss, locked rotor, thermal overload, communication er-ror, incorrect signal, or a fan failure.Wheel StatusThis alarm will occur when the ERV wheel is turned on and thewheel proxy sensor does not detect wheel motion within the settime. It will open its contact which energizes the normallyclosed rotation monitor relay. This is seen as 24vac at EXCBJ5-3 and causes the alarm. The EXCB’s D12 LED will beturned on and the OAU Motor Failure Alarm point will beturned to on (Operating Modes →OAU →ALM.1 = On).This alarm will automatically reset when motion is detected.Possible causes of this alarm are: the wheel belt breaking orslipping, wheel motor failure, proxy sensor failure or incorrectsetting, or wiring error.T418 OAU LOW CFMThis alarm indicates that the ERV cannot bring in the desiredamount of outside air. The alarm occurs when the actual out-side air CFM (Operating Modes →OAU →A.OA) is less than10% of the commanded outside air CFM (Operating Modes→OAU →C.OA) after 10 minutes. This alarm will not occurin test mode or defrost mode. The Rooftop unit might be ableto help by ramping its indoor fan up. Refer to the base controls,start up, operation, and troubleshooting manual for details. TheOAU Low CFM Alarm point will be turned to on (OperatingModes →OAU →ALM.3 = On). This alarm will automatical-ly reset if the actual CFM is within 10% of the commandedCFM. Possible causes of this are: outside air CFM setpoint settoo high, dirty filter or plugged screen, pressure tubing wrongor disconnected, wrong OA CFM curve programmed, or RTUindoor fan speed running too low.T418 OAU GENERAL ALARMThis alarm is not currently used by the ERV.Check Diagnostic LEDsUse the on board LEDs to assist in troubleshooting the Ener-gyX ® system. The EnergyX Control Board (EXCB) and theUniversal Protocol Converter (UPC) each have LEDs that canhelp in the troubleshooting process. See Tables 25-27.The EXCB has five green LEDs and one red LED. The red LEDis for power indication and the green LEDs are status indicators.The UPC has seven LEDs. There are four communicationLEDs and three status LEDs. The communication LEDs indi-cate if the translator is speaking to the devices on the networkand should reflect communication traffic based on the baudrate set. The higher the baud rate, the LEDs would becomemore solid.* Modbus is a registered trademark of Schneider Electric.Table 25 — EXCB LED IndicatorsLED COLOR DESCRIPTION STATUS IF LIGHTIS LITD9 Red 24vAC board power Board has powerD2 Green Run light Flashing ERV is RunningD12 Green ERV Wheel Status AlarmERV Wheel notrotating when itshould beD14 Green ERV Wheel FrostProtectionERV detects frost onthe wheel andrunning in FrostModeD16 Green ERV Dirty Filter Alarm Dirty FilterD18 Green ERV Blower Status Alarm Fan FailureTable 26 — EXUPC LED IndicatorsLED COLOR DESCRIPTION STATUS IF LIGHT IS LITPower Green Power Indicator Lights when power is beingsupplied to the translator.Rx1 Green Port 1 ReceivingDataLights when the translatorreceives data fromComfortLink MBB via LENRx2 Green Port 2 ReceivingDataLights when the translatorreceives data from theModbus* EXCBTx1 Green Port 1Transmitting DataLights when the translatortransmits data to theComfortLink MBB via LENTx2 Green Port 2Transmitting DataLights when the translatortransmits data to the ModbusEXCBRun Green Run indicator Lights based on translatorhealth. See Table 27.Error Red Internal ErrorindicatorLights based on translatorhealth, See Table 27.Table 27 — EXUPC LED Flash Code DiagnosticsRun LED Status Error LEDStatus ERV Module Status2 flashes per secondOff Normal2 flashes,alternating withRun LED5 minute auto - restart delayafter system error3 flashes then off Module has just beenformatted4 flashes thenpauseTwo or more devices on thisnetwork have the sameARC156 network address1 flash persecond Module is alone on the networkOn Operation halted after frequentsystem errors or controlprograms halted5 flashes per secondOn Operation start - up aborted.Boot is runningOff Firmware transfer in progress.Boot is running7 flashes per second7 flashes persecond,alternating withRun LEDTen second recovery periodafter brownout14 flashes persecond14 flashes persecond,alternating withRun LEDBrownoutAlternating withErrorAlternating withRunRestoring memory fromArchive