Daikin DPS Installation And Maintenance Manual

Also see for DPS: Installation and maintenance manual Installation and maintenance manual Installation manual Installation and maintenance manual

Contents

Daikin DPS Installation And Maintenance Manual Manual pdf 116 page image

heat puMpInverter Compressor Heating State DescriptionsThe Inverter Compressor Heating State determines theoperation of the following devices:• Inverter Compressor• Fixed Speed Compressor (if present)• Outdoor Fan(s)• 4 Way Reversing Valve (4WV)• Outdoor Expansion Valve (EVO)• Indoor Expansion Valve (EVI)• Receiver Solenoid Valve (SVR)• Bypass Solenoid Valve (SVB)Heating OffCompressor heating operation begins in the Off state When inthe Off state, all devices are off or closed The state remainshere until there is a call for heatingPre Start Pressure EqualizationIn the Pre Start Pressure Equalization state the SVB valve isopened to divert hot gas leaving the compressor directly tothe suction line to equalize the pressures in the system beforebeginning compressor operation The outdoor fan is set at 50%speed Operation remains in this state for 90 seconds When inthe Pre Start Pressure Equalization state, all devices are Off orclosed except the outdoor fan(s) and SVB The outdoor fan(s)speed is set to 50%InitializationIn the Initialization state either the Standard Initialization orAlternate Initialization sequence is used in order to managerefrigerant and assure the 4-way valve is switched TheAlternate Initialization sequence is used the first time the unitenters heating after unit power up, or when the compressorshad last operated in cooling, or if it has been a long time sinceheating has operated and it is cold outdoors Otherwise theStandard Initialization Sequence is usedTable 66: Standard Initialization SequenceSee page 86 for more information about what is a compressor “step”.Device Step 1 Step 2 Step 3 Step 4Inverter Compressor & Comp 3 Inverter Compressor Speed=minimumComp 3=OffInverter Compressor Speed=Smaller ofStep 12 or MaximumComp 3=Off ← AInverter Compressor Only Inverter Compressor Speed=minimumIf OAT≤59°F, Inverter CompressorSpeed=Smaller of Step 12 or MaximumIf OAT>59°F, Inverter CompressorSpeed=minimum← AOutdoor Fan Outdoor Fan=100% ← ← ←4 Way Valve (HeatPump) ON ← ← ←Outdoor Coil Expansion Valve (EVO)(HeatPump) EVO=0% ← B ←SVR (HeatPump) Closed ← ← ←SVBNormally OpenClose if either of the following is true:60 seconds elapses from the beginning ofStep 1Discharge superheat>18°F← ← ←Indoor Coil Expansion Valve (EVI) EVI=100% C ← ←Time Duration 10 seconds 5 seconds 5 seconds DA Inverter compressor speed is increased until the 4-way valve is seated (discharge minus suction pressure >57 psi) and aslong as the suction pressure is above 43 psi and Comp 3 remains OFFB The outdoor expansion valve is controlled to keep the suction superheat between 3 6°F and 9 0°FC Standard Initialization lasts a maximum 120 seconds It is completed early anywhere between 10 seconds and 120 secondsif discharge pressure is high (above 384 psi) or when the 4-way valve has been seated for 60 seconds (differential pressureabove 57 psi)OM 1141-3 • MICROTECH UNIT CONTROLLER 116 wwwheat puMp