Carrier 38APS025 Manual

Also see for 38APD115: Installation instructions

Carrier 38APS025 Manual Manual pdf 139 page image

139while the motor continues to run. After the compressor runs forsome time without pumping gas, the motor overload protectorwill open. The longer the compressor runs unloaded, the longerit must cool before the bi-metal disk resets. See Fig. 159 for ap-proximate reset times.To manually reset ASTP, the compressor should be stoppedand allowed to cool. If the compressor is not stopped, the motorwill run until the motor protector trips, which occurs up to 90minutes later. Advanced Scroll Temperature Protection will re-set automatically before the motor protector resets, which maytake up to 2 hours.MOTOR OVERLOAD PROTECTIONCopeland* Compressors Models with Electrical Code TF— Models with a “TF” in the electrical code (i.e.,ZP182KCETFE) have an internal line break motor overloadlocated in the center of the Y of the motor windings. This over-load disconnects all three legs of the motor from power in caseof an over-current or over-temperature condition. The overloadreacts to a combination of motor current and motor windingtemperature. The internal overload protects against singlephasing. Time must be allowed for the motor to cool downbefore the overload will reset. If current monitoring to thecompressor is available, the system controller can take advan-tage of the compressor internal overload operation. The con-troller can lock out the compressor if current draw is notcoincident with contactor energizing, implying that the com-pressor has shut off on its internal overload. This will preventunnecessary compressor cycling on a fault condition until cor-rective action can be taken.Copeland Compressors Models with Electrical Code TW orTEModels with a “TW” or “TE” in the electrical code (i.e.,ZP182KCETWD or ZP182KCETED) have a motor overloadsystem that consists of an external electronic control moduleconnected to a chain of four thermistors embedded in the motorwindings. The module will trip and remain off for a minimumof 30 minutes if the motor temperature exceeds a preset pointto allow the scrolls to cool down after the motor temperaturelimit has been reached. It may take as long as two hours for themotor to cool down before the overload will reset.NOTE: Turning off power to the module will reset it immedi-ately.For this reason, module power must never be switched withthe control circuit voltage.Current sensing boards monitor to the compressor current.The ComfortLink control system takes advantage of the com-pressor overload operation by locking out the compressor ifcurrent draw is not detected. This will prevent unnecessarycompressor cycling on a fault condition until corrective actioncan be taken.Kriwan Motor Protection Module Troubleshooting — Cope-land models with a “TW” in the electrical code (i.e.,ZP182KCETWD), have a motor overload system that consistsof an external Kriwan electronic control module. These havebeen replaced by the CoreSense* communication module formotor protection. This section is included for reference, andcontains instructions for replacing the Kriwan module with theCoreSense module in the field.Follow the steps listed below to troubleshoot the Kriwanmodule in the field. See wiring diagram on terminal box cover,or Fig. 160.CAUTIONThe electronic motor protection module is a safety devicethat must not be bypassed or compressor damage mayresult.Fig. 159 — Recommended Minimum Cool DownTime After Compressor is Stopped01020304050607080901001101200 10 20 30 40 50 60 70 80 90Compressor Unloaded Run Time (Minutes)Recommended Cooling Time(Minutes)NOTE: Times are approximate. Various factors, including high humidity, highambient temperature, and the presence of a sound blanket will increase cool-down times.CAUTIONRestoring the compressor sooner may cause a destructivetemperature build up in the scrolls.WARNINGDo not supply power to unit with compressor coverremoved. Failure to follow this warning can cause a fire,resulting in personal injury or death.WARNINGExercise extreme caution when reading compressor cur-rents when high-voltage power is on. Correct any of theproblems described below before installing and running areplacement compressor. Wear safety glasses and gloveswhen handling refrigerants. Failure to follow this warningcan cause fire, resulting in personal injury or death.CAUTIONDo not manually operate contactors. Serious damage to themachine may result.1 2 3LEGEND1 — Kriwan Motor Protection Module Power2 — Kriwan Control Circuit Connections3 — Motor Thermal SensorFig. 160 — Kriwan Motor Protection Wiring*Trademarks of Emerson Climate Technologies.