Carrier 38APS025 Manual

Also see for 38APD115: Installation instructions

Carrier 38APS025 Manual Manual pdf 136 page image

136Table 62 — Operating ModesSERVICEService Test — The controls system allows for the oper-ation of various components in a Service Test mode. While op-erating in Service Test mode, outputs can be tested and variouscomponents run to confirm proper operation. While operatingcompressors in Service Test mode, the capacity control algo-rithm and all safeties are active. Confirm airflow in the evapo-rator before starting the unit in Service Test.NOTE: Main power must be on for Service Test to function.The Service Test function should be used to verify properoperation of condenser fan(s), compressors, minimum loadvalve solenoid (if installed), and remote alarm relay. To use theService Test mode, the Enable/Off/Remote Contact switchmust be in the OFF position. Use the display keys and ServiceTest Mode and Sub-Mode Directory table in Appendix A toenter the mode and display TEST. Press twice so thatOFF flashes. Enter the password if required. Use either arrowkey to change the TEST value to the ON position and press. Place the Enable/Off/Remote Contact switch in theENABLE position to begin Service Test. Press andthe up or down key to enter the OUTS, CMPA or CMPB sub-mode.Test the condenser fans, liquid line solenoids and alarm re-lay by changing the item values from OFF to ON. These dis-crete outputs are then turned off if there is no keypad activityfor 10 minutes. Use the arrow keys to select the desired per-centage when testing Motormaster® V controller or number ofseconds for the digital unloader solenoid, if equipped. All com-pressor outputs can be turned on, but the control will limit therate by staging one compressor per minute. Minimum loadvalve relays/solenoids, if installed, can be tested with the com-pressors on or off. The relays under the CMPA or CMPB modewill stay on for 10 minutes if there is no keypad activity. Com-pressors will stay on until they are turned off by the operator.The Service Test mode will remain enabled for as long as thereis one or more compressors running. All safeties are monitoredduring this test and will turn a compressor, circuit or the ma-chine off, if required. Any other mode or sub-mode can be ac-cessed, viewed, or changed during the TEST mode. TheMODE item (Run StatusoVIEW) will display NO as long asthe Service mode is enabled. The TEST sub-mode value mustbe changed back to OFF before the unit can be switched to En-able or Remote Control for normal operation.MODE ITEM EXPANSION DESCRIPTION SYSTEM EFFECTD.OIL Digital Oil Recover ModeDigital compressor has been runningbelow standard Maximum A1 UnloadTime (ConfigurationoUNIToMAX.T) formore than 30 minutes. Digital compres-sor will load to 100% for 30 seconds.Digital compressor will load completely.supply air temperature may be lower thanControl Point (Run StatusoVIEWoCTPT).L.OUT OAT Below Lockout TempAmbient temperature is below field config-urable setting, causing mechanical cool-ing to be disabled.Unit is not allowed to start.MD05 Ramp Load Limited Prevents rapid staging of compressors atstart-upMay not be able to supply air at the Con-trol Point (Run StatusoVIEWoCTPT)MD06 Timed Override in Effect Unit is operating outside of normal occu-pied time periodNormal capacity control is enabled.MD09 Slow Change OverrideSupply air temperature is close to andmoving toward the Control Point(Run StatusoVIEWoCTPT)Capacity stage changes are prohibited.Unit may not supply air at the ControlPoint(Run StatusoVIEWoCTPT)MD10 Minutes Off Time Active Unit is prohibited from starting until thetimer has expiredUnit is not allowed to start.MD14 Temperature Reset Unit is operating with a modified set point Unit is operating with a modified set pointunder normal capacity control.MD15 Demand Limited Unit capacity is being limited by aDemand Limit commandUnit may not be able to deliver the desiredsupply air temperature.MD17 Low Temperature CoolingSupply Air Temperature is decreasingfaster than 0.5 F (0.3 C) and the differ-ence between the Supply Air Tempera-ture and Control Point (RunStatusoVIEWoCTPT) exceeds a calcu-lated value.Unit may unload.MD18 High Temperature CoolingSupply Air Temperature and and its rateof change are increasing, and the differ-ence between the Supply Air Tempera-ture and Control Point (RunStatusoVIEWoCTPT) exceeds a calcu-lated value.Unit will automatically load.MD21 High SCT Circuit A Circuit SCT exceeds a calculated limit No additional stages of capacity will beadded. Unit may unload to lower SCT.MD22 High SCT Circuit BMD23 Minimum Comp On Time Compressor has not completed its mini-mum run timeCompressor will remain running. SupplyAir Temperature may be lower than Con-trol Point (Run StatusoVIEWoCTPT).MD25 Low Sound Mode Not supported Not SupportedMDTG Time Guard Active Prevents rapid cycling of a compressorMay allow the unit to overshoot the setpoint or not allow a compressor to start ifrequired.ENTERENTERESCAPE