Daikin DPS005 Installation And Maintenance Manual

Also see for DPS003: Installation and maintenance manual Manual

Contents

Daikin DPS005 Installation And Maintenance Manual Manual pdf 94 page image

IM 1125-7 • REBEL ROOFTOPS 94 www.DaikinApplied.comC heCk , TesT and sTarT proCeduresC heCk , TesT and sTarT proCeduresEconomizer Start-Up1 Check whether the outdoor air is suitable for free cooling.2 At the keypad, set the cooling setpoint low enough so thecontroller calls for cooling.3 Place the unit into cooling mode through the keypadmenu4 Observe the outdoor air dampers:a If the outdoor enthalpy is low, the control algorithmshould start to modulate the dampers open tomaintain the discharge air setpoint.b If the outdoor enthalpy is high, the dampers shouldmaintain their minimum position.NOTE: It may not be possible to check the economizeroperation in both low and high enthalpy states on thesame day. If this is the case, repeat this procedure onanother day when the opposite outdoor air enthalpyconditions exist.Compressor Start-UpWith the supply fan operational, prepare for compressoroperation1 Verify that the crankcase heaters are operating. Theseshould operate for at least 24 hours before startingthe compressorsPerform the Following Procedure:1 At the keypad, set the cooling setpoint low enough sothat the controller will call for cooling.2 Verify that compressor #1 starts. If the compressor motorhums but does not run, verify that it is phased correctlybetween the inverter board and compressor.3 The compressor should operate continuously while thereis a call for cooling. If the compressor cycles on and offon its low pressure switch, perform the following:a Verify that the circuit is not short of refrigerant.b Check for low airflow across the evaporator coil.c. Check for clogged filters.d Check for restricted ductwork.e Check for very low temperature return air entering theunitf Verify that the liquid line components, expansionvalve, and distributor tubes are feeding theevaporator coil.g. Verify that all air handling section panels are closed.4 Verify that the condenser fans are cycling and rotatingproperly (blowing air upward). When the compressorstarts, at least one condenser fan should also start.Checking SubcoolingFollowing are recommendations for checking subcooling:1 Run unit until it reaches steady state. Close the unitsection doors. Running the unit with its doors open willaffect system operation.2 Subcooling can be read from the MicroTech III unitcontroller.CAUTIONLow ambient temperature hazard Can causecompressor damage Do not attempt to start up andcheck out the refrigeration system when the outdoor airtemperature is below 0°F.NOTICEVenting refrigerant to atmosphere is not allowed permost local laws and/or codes.