Desert Aire SelectAire Plus SP Series, Installation And Operation Manual

Page 1: ...ation circuits consist of scroll compressors for high performance and long life Model features passive latent heat enhancement device for high moisture removal capacity SP systems include an exclusive exhaust air heat recovery system and air flow balancing SP s dual refrigeration circuit design allows staging to minimize energy consumption and optimize energy recovery SP SelectAire Plus Series Ene...

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Page 3: ...perly installed and maintained in accordance with the Desert Aire Installation and Operation Manual provided with each unit and or other documentation provided 2 The Start Up Report must be completed and returned to Desert Aire Service for evaluation If no deficiencies are identified a Warranty Validation Letter will be issued that provides all warranty dates and coverage If installation or start ...

Page 4: ...representative is authorized to make any warranty or assume any liability not strictly in accordance with the aforementioned Inquiries regarding warranty matters should be addressed to Desert Aire Corp c o Service Manager N120 W18485 Freistadt Road Germantown WI 53022 PH 262 946 7400 FAX 262 946 7401 E MAIL service desert aire com Additional copies of this manual can be purchased for a nominal fee...

Page 5: ...nstructions If you cannot reach your gas supplier call the fire department Installation must be performed by a qualified installer service agency or gas supplier More safety information is included in the gas furnace manual therefore it must be kept with the appliance for future reference A The included gas fueled furnace s does not have a pilot It is equipped with a direct spark ignition device t...

Page 6: ...gas control knob clockwise to OFF position or switch down for single stage 6 Wait five 5 minutes to clear out any gas Then smell for gas including near the floor If you smell gas STOP Follow B in the safety information above on this label If you don t smell gas go to next step 7 Turn gas control knob counterclockwise to ON position on 2 stage units or flip up to ON for single stage units NOTE DO N...

Page 7: ...EW INLET PRESSURE TAP OUTLET PRESSURE TAP PRESSURE REGULATOR ADJUSTMENT CAPS ATMOSPHERIC PRESSURE REFERENCE PORT WITH INTERNAL VENT LIMITER Honeywell V8944 Gas Valve for 500 000 and 600 000 models Desert Aire SP Manual 2 Stage Gas Valve ...

Page 8: ...id possible death or injury Indicates an imminently hazardous situation which if not avoided will result in death or serious injury Indicates a potentially hazardous situation which if not avoided could result in death or serious injury Indicates a potentially hazardous situation which if not avoided could result in minor or moderate injury Caution used without the safety alert symbol indicates a ...

Page 9: ... 2 8 2 Water Temperature Sensor 31 2 8 3 Installation of Sensors for the SelectAire Plus 32 2 8 3 1 Indoor Static Sensor Installation 32 2 8 3 2 Outdoor Static Sensor 33 2 8 4 Installation of VOC Monitoring Sensor 34 2 9 Auxiliary Heating Control Wiring 35 2 9 1 Auxiliary Heating Dry Contact Closure 35 2 9 2 Auxiliary Heating Proportional Signal 35 2 10 Gas Heater Optional 36 2 10 1 Gas Heater Ins...

Page 10: ...tions if applicable 54 2 16 1 Outdoor Air Hood Assembly if applicable 54 2 16 2 Exhaust Hood Assembly Instructions 54 2 17 Combination Moisture and Liquid Indicator 55 2 18 Crankcase Heaters Heat Tape GFI Outlets and Lighting 56 2 18 1 Crankcase Heaters and Heat Tape 56 2 18 2 GFI Outlets and Lights 56 2 18 2 1 Dedicated 120V AC Powered Lights GFI and Receptacle Standard 56 2 18 2 2 GFI and Lights...

Page 11: ...Water Chemistry 85 5 4 Recommended Controller Settings 85 5 4 1 Controller Set Points 85 5 5 System Operating Modes 85 5 5 1 Basic Sequence 85 5 5 2 Blower Operation 87 5 5 3 Dehumidifier Operation 88 5 5 4 Cooling Operation 88 5 5 5 RecoverAire ER Energy Recovery Operation 88 5 5 6 Damper Operation 88 5 5 6 1 Outdoor Air and Outside Air Bypass Dampers 88 5 5 6 2 Evaporator Bypass and Thru Dampers...

Page 12: ...12 Desert Aire SP Manual ...

Page 13: ...o equipment damage personal injury or death 2 Lifting method and procedure must comply with all local and national codes and regulations 3 The use of safety slings in addition to lifting lugs is required 4 Do not lift the dehumidifier in high winds or above people Desert Aire dehumidifiers are solidly built and can be very heavy Avoid personal injury and damaged equipment by planning the installat...

Page 14: ...14 Desert Aire SP Manual Figure 1 Typical Rigging for the SP Dehumidifier 1 Do not tip the dehumidifier on it s side 2 Avoid dropping the unit down stairways or subjecting it to severe mechanical shock ...

Page 15: ...the condensate trap Install blocks underneath each corner and each lifting lug Figure 2 Dehumidifier with Blocks Installed for Trap Clearance Install outdoor dehumidifiers equipped with an outdoor air intake away from plumbing vents furnace flues or equipment which could contaminate the air supply If the dehumidifier is to be mounted on a roof curb make sure that the curb has been properly mounted...

Page 16: ... AS HIGH AS POSSIBLE IN ROOM INSTALL TURNING VANES IN ALL ELBOWS INSULATED OUTSIDE AIR INTAKE DUCT SIZE FOR CODE REQUIREMENTS MOTOR OPERATED DAMPER WEATHER PROOF INTAKE HOOD REMOTE CONDENSER TEMPERATURE AND HUMIDITY CONTROLS MECHANICAL EXHAUST WITH BACK DRAFT DAMPER WALL OR ROOF MOUNTED NOTE CAPACITY SHOULD NOT EXCEED INTAKE VOLUME ...

Page 17: ...SATE PIPING Figure 4 Typical In Ground Duct Layout You may use galvanized sheet metal ducts for all but underground installations and severely corrosive environments Do not use fiberglass duct boards or acoustic duct liner for air distribution in highly humid applications such as pool room dehumidification If a duct must be installed in an unconditioned area or if you are installing an outdoor air...

Page 18: ... REGISTER VAPOR BARRIER Figure 5 Soffit Duct Layout with Skylight Grille Install return air grilles or louvers as high as possible in the enclosure Normally one centrally located grille will be adequate Avoid under sizing this grille or short circuiting of air with nearby supply registers Select grilles and diffusers for low static pressure loss and proper throw and CFM rating Keep the noise crite...

Page 19: ...factory installed damper and actuator The outdoor air is distributed between the evaporator and the reheat condenser coils The unit controller will energize dry contacts to control any additional outdoor air dampers This controller will also control the internal exhaust fans Figure 6 shows typical ducting for the SelectAire Plus unit configured for indoor installation The outdoor air duct used for...

Page 20: ...ol of field supplied dampers An outdoor SelectAire Plus unit is also provided with an exhaust hood This is shipped loose for field installation See Section 2 16 for installation instructions Figure 7 Outdoor Dehumidifier The outdoor air hoods are equipped standard with a wire mesh bird screen material attached to a rack at the lower face of the hood If needed the rack can be removed from the hood ...

Page 21: ...luded in the rack The rack can be removed in a similar fashion for basic cleaning Particulate such as cottonwood airborne seeds or dust can often be wiped or vacuumed off of the surface of the filter If a more thorough cleaning is warranted the pre filter can be removed from the rack by removing the 1 4 turn fasteners holding the screen to the rack Use Dawn liquid detergent and hose directed water...

Page 22: ...nsate drain line There is a drain pan located under the internal reheat condenser coil that is for purposes of draining the water away during cleaning of the reheat coils For convenience this is piped to the same drain as the condensate If you wish to use the drain pan during cleaning ensure that the cleaning solutions and the contamination to be washed from the coils will not cause any issues for...

Page 23: ...below 6 0 Do not use water with high concentration of sulfur chlorine or sodium chloride A dedicated circulating pump must be used unless the main pump can develop enough head to overcome the combined resistance of the water condenser and the piping connected to it See Section 2 4 2 for the required water flow rate and head pressure for your application Install an air eliminator at any high point ...

Page 24: ...e water circuit of the dehumidifier See Figure 10 for recommended pool water piping Note that this figure is intended to be a general guide only and may not match your installation exactly All piping must meet state and local codes 120V 15A Power Connection Power is required for water heat exchanger when equipped Damage caused by freezing is not covered under warranty Check power and operate regul...

Page 25: ... Connector 4 Piping to Remote Condenser 5 Desert Aire Dehumidifier 6 Filter Rack Assembly with Filters 7 Return Air 8 Vibration Isolators 9 P Trap 10 Base If Required LEGEND 11 Check Valve 12 Ball Valve 13 Flow Meter 14 Main Pool Heater 15 Auxiliary Pump 16 Filter Assembly 17 Main Pool Pump 18 Water Temp Sensor Dry Well 19 Water Inlet 20 Water Outlet ...

Page 26: ...ng is included a factory supplied water temperature sensor and an aqua stat well will be supplied per pool water circuit See Section 2 8 for details on control and sensor location Circuit 70 A 80 A 70 B 80 B Pool Water Flow Rate and Pressure Drop 60 GPM 25 ft W C 70 GPM 25 ft W C 80 GPM 25 ft W C Figure 11 Standard Unit Water Flow Rates for Units Equipped with this Option 2 5 Auxiliary Air Heat Co...

Page 27: ... 12 Remote Condenser Line Size Summary for Units Equipped with this Option Performance rated at return air conditions of 82 F 60 RH 50 Actual Line Length 62 5 Equivalent Line Length at the design air flow rate 2 7 High Voltage Wiring You must follow all local codes when you connect the high voltage wiring to the dehumidifier Attach the wires to the disconnect switch mounted on the electrical panel...

Page 28: ...ected to the pool equipotential bonding grid in the field when required by code This also removes the possibility of differences in potential between metals in the pool water and the water condenser that may accelerate corrosion The bonding lug should be connected to the equipotential grid with 8 AWG or larger solid copper conductor 2 8 Controls and Sensors The standard Desert Aire SP series dehum...

Page 29: ...outlets or solar radiation Cold spots due to a cold wall or drafts from stairwells doors windows or supply register outlets Dead spots such as behind doors or in corners where room air cannot circulate freely A supply air temperature sensor and duct holder is also provided to be installed downstream of any field provided heaters Mount this in the supply duct and seal the penetration Install at lea...

Page 30: ...ature humidity sensor should be installed in the radiation shield This assembly then should be installed outdoors near the dehumidifier when the SP unit is installed indoors The shield is included to prevent additional heat loading from the sun and to prevent direct moisture contact with the sensor With the curved shape and color of the plates air flow is able to move across the sensor to keep rad...

Page 31: ...ensor wires are pre installed to the SP control panel and terminate in a junction box with quick connect wire lever locks The wiring color coding is as follows Junction Box White Green Red Black Sensor Harness White Blue Brown Black 10 Attach the wire harness as shown in Figure 16 below to the T RH 309 Sensor The sensor has a female end and the male wire harness threads onto the T RH 309 Sensor Fi...

Page 32: ...nd operable windows that may cause pressure fluctuations Locate a minimum of 3 above the floor level in the pool area Note that in rooms with extremely high ceilings greater than 30 it is preferable to locate the sensor a minimum of halfway up the wall This is due to building stack effect where the pressure may become higher at the ceiling than at the floor The sensor can be mounted directly to dr...

Page 33: ...essure sensor should be mounted at least 12 inches above surrounding obstacles and a minimum of 24 inches from a wall or Air Handling Unit Do not mount under awnings or other projections within fifteen feet Do not mount near economizers intakes or exhaust fans or barometric dampers Do not mount within 10 of building corners or parapet walls Figure 18 Outdoor Static Pressure Sensor A detailed drawi...

Page 34: ...etermined concentration A sensor will be provided in the unit or shipped loose for field installation depending on the configuration ordered VOC Sensor in the Unit If ordered with Sensor in Unit the sensor is included downstream of the filter rack The level of the VOC in parts per million will immediately be available when the controller is powered on It should be noted that for reasonable accurac...

Page 35: ...ime of order 2 9 1 Auxiliary Heating Dry Contact Closure Desert Aire will provide a dry contact closure to interlock with the building heating system This contact closure is normally used to interlock with a gas or electric duct heater which has its own power supply transformer When the room air temperature drops below the set point the dry contact will close to energize the auxiliary heater See t...

Page 36: ...he contact rating is shown on the electrical schematic Use a transformer and relay to energize loads that are higher than the contact rated current draw or power 2 10 Gas Heater Optional 2 10 1 Gas Heater Installation Safety The Desert Aire dehumidifier may be equipped with an optional Category III gas fired heater to provide air heating during the winter months You must read and understand the fo...

Page 37: ...more than a trace 0 3 grains per 100 cubic ft of hydrogen sulfide gas Check with your gas supplier For initial start up of the furnace after installation it may be necessary to purge the air out of the gas line This should be done by a qualified heating contractor If excessive gas escapes when purging the gas supply at the union allow the area to ventilate for at least 15 minutes before attempting...

Page 38: ...ping from the LP tank to the furnace must follow the recommendations of the gas supplier A readily accessible certified manual shut off valve with a non displaceable rotor member should be installed within six feet of the gas equipment it serves A union or flanged connection shall be provided downstream from the manual valve to permit removal of controls Provide a 1 8 N P T plugged tapping at the ...

Page 39: ...ncreased requirements Refer to National Fuel Gas Code for additional information on line sizing Propane 56 45 38 34 31 28 26 24 23 21 19 17 16 Natural 190 152 130 115 105 96 90 84 79 72 64 59 55 Natural 350 285 245 215 195 180 170 160 150 130 120 110 100 1 2 3 4 1 Propane 116 93 79 70 64 59 55 51 48 44 39 36 34 Propane 214 174 149 131 119 110 104 98 92 79 73 67 61 Capacity of Piping Cubic Feet per...

Page 40: ...ow shown Total input load Btu h on line 75 000 125 000 187 500 250 000 375 000 500 000 lf the length of line between second stage regulator and furnace is this long 25 100 1 2 O D Copper 50 75 10 5 8 O D Copper 20 30 40 50 3 4 Black Pipe 1 Black Pipe 1 Black Pipe 3 4 Black Pipe 3 4 Black Pipe 3 4 Black Pipe 5 8 O D Copper 3 8 O D Copper 3 8 O D Copper 1 2 O D Copper 1 2 O D Copper Figure 22 LP Gas...

Page 41: ...ockwise to decrease pressure Consult the valve manufacturer s literature provided with the heater for more detailed information 2 10 3 Gas Heater Location The following items must be considered when choosing the size and location of the furnace Note that dehumidifiers designed for outdoor use are already equipped with combustion air intakes and venting means Field installed venting is only require...

Page 42: ...exhaust piping to the outdoors Since the design of the system will be unique to each job site this must be properly completed by the design professional responsible for the overall mechanical system design Hazards of Chlorine The presence of chlorine vapors in the combustion air of gasfired heating equipment presents a potential corrosive hazard Chlorine found usually in the form of Freon or degre...

Page 43: ...orizontally vented burner Avoid locating the vent terminal on a wall facing the prevailing winds or wideopen areas When this is not practical choose locations that protect the vent from strong wind such as behind a fence or hedge Note the vent terminal must be located a sufficient distant from bushes shrubs and vegetation so as not to have the flue products restricted or blocked by such vegetation...

Page 44: ...ollar 2 10 4 2 Assembly Instructions Use gloves when handling vent parts To assemble joints of pipes and fittings first make sure that the lock ring is moved upward sufficiently to clear the formed tabs Check the tabs to see that they are projecting slightly outward from the pipe so that the upper section will slide down over the end of the lower section to which it is being joined Look up the wor...

Page 45: ...e above the flashing The storm collar Figure 23d D in Figure 24 must be placed immediately above the roof flashing and sealed with roof cement or RTV silicone to seal the joint between the storm collar and the vent pipe Next install the vent cap Figure 23a A in Figure 24 The cap has a spring clip which engages and locks automatically when the cap is pushed onto the pipe Figure 24 B Vent Fully Asse...

Page 46: ...5a Top Final Single B Vent Installation and Figure 25b Bottom Final Dual B Vent Installation 2 10 8 Gas Heater Condensate Drain When the SelectAire Plus unit is provided with a gas heater trap the condensate connections as shown in Figure 26 Traps for each heater section must be trapped independently The condensate drain may be constructed with Schedule 40 PVC pipe fittings and components All join...

Page 47: ...rpose Condensate drain lines must always be sloped toward the discharge for proper condensate removal For installation where the building drain lines are above the level of the duct furnace drain system a condensate pump may be required Note that the products of combustion can be highly corrosive Ensure that the condensate pump is rated for gas heat flue condensation 2 10 9 Induced Draft Fan An in...

Page 48: ...y water heater Note Do not use the aqua stat mounted on the auxiliary heater for temperature control This can lead to excessive water temperature fluctuation It may also permanently prevent the dehumidifier from heating pool water if the set point of the heater aqua stat is higher than the water heating set point of the dehumidifier 2 12 Smoke Alarm Interlock Desert Aire SP series dehumidifiers ar...

Page 49: ... Hail Guard and Pre Filter Assembly Instructions Optional Hail Guard and Pre Filters are available for use over the packaged condenser coil 2 14 1 Packaged Condenser Hail Guard Hail Guard netting will arrive mounted to the surface of the packaged condenser units The guard netting will be attached with black clips These clips are permanently mounted to the unit and will not need to be removed for m...

Page 50: ...al If the unit has been designed for a sectioned unit installation please follow the instructions below in addition to the standard installation instructions included within the unit 2 15 1 Rigging Instructions Refer to the installation instructions included with the unit for lifting procedure In addition unit sections must be properly braced to ensure safe lifting without damage to the unit The u...

Page 51: ...ded tape to the seam of both mating cabinet sections see Figure 29 Align the provided mounting strips with each section edge and apply pressure to secure the strips to the cabinet sections Use provided drive 8 screws through all holes in each flange Repeat the above steps to install the top flange sections see Figure 30 Figure 30 Top Cabinet Fastening When pulling sections together that contain re...

Page 52: ...gs and copper tubing has been set in place Wrap critical components such as valves with a cool damp rag to reduce possibilities of heat damage Braze the line connections together with Sil Phos 5 brazing alloy once fittings and copper tubing has been set in place Using a cool damp rag wipe the outside of the joint taking care not to get water inside the assembly Continue cooling until assembly is c...

Page 53: ...D Control voltage cables will be tagged and need to be reconnected to their respective terminal blocks for compressor control refrigeration controls damper actuators valves etc Connect cable to the corresponding multi tier terminal block as shown in Figure 31 e g SOL217 Connect wires to corresponding color on the terminal block As an example red wires connect to RED connection Note Green wires ter...

Page 54: ...t up the return hood Below are lists of the necessary tools and parts required for performing the installation 1 Align the exhaust hood with the existing holes and support in place 2 With the 1 4 bit installed in the power driver insert the top 10 screws to the cabinet starting with the far right top screw then far left top screw and then installing the remaining 8 top screws 3 Finalize the instal...

Page 55: ...e safe operating range The colors indicate the following moisture content in PPM Dark Green Less than 75 PPM Chartreuse 75 150 PPM Yellow Over 150 PPM Change the drier when the color is in the caution or wet range The action of the indicator element is completely reversible and will change color whenever the moisture content of the system changes The indicating element may change color rapidly on ...

Page 56: ...ered by the dehumidifier circuit optional using a dedicated transformer 2 18 2 1 Dedicated 120V AC Powered Lights GFI and Receptacle Standard In a standard configuration dehumidifier 120 VAC power will be supplied to the dehumidifier s panel by others A separate terminal is available for this connection It will be necessary to take precautions when powering up and when powering the unit down that ...

Page 57: ... proper phasing of the compressors per Section 2 7 Check for proper phasing of the optional remote condenser power supply The head fan has an EC motor and will not need to be phased however additional fans 2nd 3rd 4th etc should be phased Test the phasing by bumping the blower contactor Verify that the blower rotates in the proper direction If it rotates the wrong direction switch any two of the t...

Page 58: ... identify compressor knife switches Confirm that the compressor is off to prevent the refrigeration from running while you balance the air 3 2 1 Airflow Setup of SelectAire Plus The SelectAire Plus system includes features to help automate the setup and operation of the unit The system is substantially automated and airflow balanced at the factory for the specified airflows and static pressures At...

Page 59: ...ed immediately Figure 37 Dehumidifier Side View Showing Direction of Airflow Supply Airflow Setup 1 Check the condition of the air filters They should be relatively clean during the setup procedure The airflows have been set at the factory based on the information provided at the time of order Check the programmed values against the latest schedule documents 2 With the unit supply fan and exhaust ...

Page 60: ... of order for each mode of operation When setting up the unit the capability for each mode should be confirmed Unoccupied Mode Outdoor Air Setup Units with Low Exhaust Option Only In certain installations that are equipped with a Low Exhaust duct or similar device that exhausts air constantly there may be a desire to introduce some outdoor air during unoccupied mode The SelectAire Plus system allo...

Page 61: ...tes a restriction or damper may need to be placed in the return air duct Consult the factory for further recommendations Exhaust Airflow Setup The unit exhaust airflow rate should be confirmed for each mode that was specified at the time of order to ensure that the duct system static pressure encountered allow for proper flow and zone negative pressurization Ensure all doors and windows to adjacen...

Page 62: ...r and outdoor air are able to be maintained at the proper flow rates The SelectAire Plus system operation will automatically adjust to accommodate normal increase in static pressure drop but excessive filter loading will restrict airflow Filters should be monitored and replaced as required Evaporator Settings and Cool Exhaust Airflow There may be additional display screens for the evaporator and c...

Page 63: ...ween heating and cooling is not expected however It is recommended that as a final check that the unit be released from all overrides offsets and returned to the expected set points Observation of the typical operation under load is an invaluable tool in ensuring that all aspects of the system are working as anticipated Observing the unit control the space for a few cycles is recommended This can ...

Page 64: ...h units that contain POE oils as moisture will be absorbed quickly and cannot be removed with a vacuum Never open the system while under a vacuum Should the system require opening to repair a leak or other service when in a vacuum fill with dry nitrogen to atmospheric pressure before opening Have a Schrader core replacement tool available when servicing the refrigeration system Although rare defec...

Page 65: ...bled out of the lines and check that an air bleed valve has been installed at any high points in the water lines If the circulating pump is not set for continuous operation make sure it properly interlocked with the dehumidifier Temporarily shut off the water flow to the unit to verify that the factory installed water flow proving switch operates correctly Verify that the pool water temperature se...

Page 66: ...ather than pushed further in Be sure to carefully read and follow the manufacturer s recommendations before using any cleaning fluid The use of filter driers in the system piping is recommended along with a sight glass that has a moisture indicator Replace the filter dryer s as needed See Section 2 17 Note Refrigerant conversions are beyond the scope of this manual and should only be performed by ...

Page 67: ...on the prescribed quarterly cycle will void the warranty and may result in reduced efficiency and durability in the environment A routine two step quarterly coil cleaning is required to maintain warranty Step one is to clean the coil with the below approved coil cleaner see approved products list under the Recommended Coil Cleaners section Step two is to use the approved salt chloride remover unde...

Page 68: ...oated coils These cleaners can be very difficult to rinse out of the coil and can accelerate the corrosion attack of the coil High Velocity Water or Compressed Air High velocity water from a pressure washer or compressed air should only be used at a very low pressure 100 psi to prevent fin and or coil damages The force of the water or air jet may bend the fin edges and increase airside pressure dr...

Page 69: ...ium size nozzle spray not a solid stream and not a wide fan but somewhere in the middle Work in sections panels ensuring that all areas are covered and kept wetted Apply the cleaner to unit interior air exiting side of coil surfaces first Work in sections panels moving side to side and from top to bottom Generously soak coils by spraying cleaner directly on and into the fin pack section to be clea...

Page 70: ...llow to dry before rinsing Using pressurized potable water 100 psi rinse the CHLOR RID and dissolved chlorides salts off of the coils continuing to always work in sections panels Starting at the top of the coil begin rinsing the coil form side to side until you reach the bottom Repeat as many times as is necessary to ensure all coil sections panels have been completed and are thoroughly rinsed Rei...

Page 71: ...rical shock and or death Regular inspection and if necessary cleaning is necessary to prevent a blade imbalance due to the ingress of dirt Clean the fans flow area and entire fan with a moist cloth Do not use aggressive paint solvent cleaning agents when cleaning Never use a high pressure cleaner or spray jet to clean Avoid letting water permeate into the motor and the electrical installation Afte...

Page 72: ...return Drain the coil by opening all drain valves and or the drain plug Remove the vent plug to aid the draining process Once the coil has been fully drained the blower can be hooked up Caps installed in the piping on straight runs going to the supply and return connections are ideal points to hook up the blower The air vent and drain plug are not suitable locations for hooking up the blower Cauti...

Page 73: ... opening all drain valves and or the drain plug Remove the vent lug to aid the draining process Close the drain valve s and drain plug Connect the flushing system to the coil A typical system is shown in Figure 40 With the throttling valve closed start the pump and operate until the air vented from the coil Next close the air vent Open the throttling valve about half way and circulate the fluid th...

Page 74: ...t range The action of the indicator element is completely reversible and will change color whenever the moisture content of the system changes see Section 2 17 Other When either acid or wax is the major contaminant involved the cores should be left in the system at least three days to come to equilibrium thereby removing the maximum amount of contaminants The cores will remove their maximum amount...

Page 75: ...d of the tubular screen Fasten finger tight the wing screw to assembly The screw when properly fastened tightens the components in the assembly thereby prohibiting component movement and dirt bypassing around the cores Assemble the end spring on to the wing screw The design of the screw holds the spring in position so that the end plate can be easily installed especially when the shell is mounted ...

Page 76: ...76 Figure 41 Filter Drier Assembly Desert Aire SP Manual ...

Page 77: ... failed Use a voltmeter to trace the low voltage control wiring Determine if voltage is applied to the holding coil of the blower contractor If there is no voltage at the holding coil check the blower overload the control transformer the smoke alarm interlock or the optional voltage monitor relay If the dehumidifier uses a non standard controller or if the blower is cycled by the building manageme...

Page 78: ...y blow the air vertically upward Check the three way heat reclaim valve for proper operation This valve which is installed in the compressor discharge line diverts hot refrigerant vapor to the various condensers on units equipped with optional pool water heating or remote condensers The valve spool may be stuck in the middle of the valve where it blocks the outlets to both condensers You can verif...

Page 79: ...er Check that all service valves and solenoid valves in the liquid line are energized or fully open Verify that there are no restrictions or debris in the liquid line solenoid the filter drier the expansion valve or the distributor Check to see that the system is properly charged and that the liquid line sight glass shows no bubbles The refrigerant on an undercharged system can migrate to the cold...

Page 80: ...for details Make sure that the water filters are not clogged Verify that the water condenser and pool water lines are free of fouling and scaling Check that all service valves and solenoid valves in the liquid line are energized or fully open Verify that there are no restrictions or debris in the liquid line solenoid the filter drier the expansion valve or the distributor Desert Aire SP Manual ...

Page 81: ...ods of liquid refrigerant return There are fewer moving parts in a scroll compressor subject to wear compared to alternative compressor designs Nonetheless there are still many mechanical and electrical parts with close tolerances Replacement of the compressor may be required during the normal service life of the dehumidifier Inspection and Initial Diagnosis Generally the compressor will have two ...

Page 82: ...must be used depending on the results of the test above Any Compressor Service A new filter dryer must be installed when the system has been opened See Section 5 6 for component replacement If there is no acid or particulates indicated the new compressor can be installed and run Proceed to Testing and Final Diagnosis Acid Indicated Install a suction line filter shell and charcoal activated core su...

Page 83: ... during the first hour of operation Compare the reading taken earlier If the pressure differential across the filters is 5 PSI or greater than the initial reading isolate the filters using the valves installed and recover the refrigerant from the filters Replace cores If activated carbon filters were installed in the suction side to remove acid replace with similar cores If a secondary filter was ...

Page 84: ...failure and the proper cleanup of the system must be addressed to avoid repeat compressor damage 5 2 Recommended Duct Design You must use proper duct design to ensure that the dehumidifier operates efficiently and without problems Undersized or restrictive ducts reduce the system airflow which can cause premature compressor failure Use the following diagrams as a guide when you design the duct sys...

Page 85: ...hat the refrigeration circuit is activated only when it is necessary RECOMMENDED SET POINTS Humidity 50 to 60 RH Air Temperature 2 to 4 F above the pool water temperature Never disable a dehumidifier in a pool room application unless the pool has been drained Even when not in use pool water continues to evaporate adding moisture to the air During these periods of high humidity moisture will seep i...

Page 86: ...order to offset any amount of exhaust that may be extracted from this separate system Unoccupied mode is engaged when no other mode is presently engaged Occupied Mode This mode is used when a typical amount of occupancy in the space is to be encountered Occupancy can be commanded with any of the following Internal Occupancy Schedule via an integral seven day programmable time clock a contact closu...

Page 87: ...oor air The amount of outdoor air in each mode may be limited through the controls if desired but the space must be kept at a negative static pressure in order to avoid mold and property damage Note that condensation may occur when cold outdoor air is mixed with warm humid return air inside the dehumidifier During the winter months this moisture can freeze and cause serious damage to the equipment...

Page 88: ... does not satisfy this relative humidity requirement the second sensible circuit Circuit A will come on line to meet the requirement This is called the second stage of dehumidification 5 5 4 Cooling Operation Cooling mode and stages are enabled as the temperature within the space rises In cooling mode Circuit A is the first stage and Circuit B is the second stage If equipped with a co axial pool w...

Page 89: ...at coil will be active most times The unit may occasionally shift to cooling mode on one or both circuits especially during mid day when the solar load is high During the night time hours when the unit is unoccupied and ambient starts to cool the unit will be in dehumidification mode less frequently and auxiliary heating may become active Ambient Condition Hot and Humid Typical Summer Day Unit wil...

Page 90: ...e tubes and the warmth from the tubes is exchanged into the air Electric heaters use the same method but instead of using the combustion process electrically heated elements make contact with the air to warm it Lastly hot water coils use a tube and fin arrangement Supplied hot water is pumped through the tubes The tubes transfer heat to the perpendicular fins and the air passing through absorbs th...

Page 91: ...d off Heaters are sized for extreme conditions typically the 99th percentile heating capacity At many times of the year the heater is essentially oversized Depending on the location of the supply ducts and diffuser configurations the variations may create drafts within the space Also if the air temperature is very low and the heater cycles off the supply air temperature may be lower than the space...

Page 92: ...ry contact will open In addition if the zone is sensed at greater than 85 F at any point the contact will open limiting heater overshoot due to poorly tuned loop 5 5 9 Suction Pressure Operation The low suction pressure alarm and trip protects the SP unit Whenever the suction pressure in either circuit falls below 58 psig the unit compressors will shut off with an alarm indication The compressors ...

Page 93: ...ist in storing charge The low side pressure should be monitored closely while using this procedure to store charge Under no circumstances should a compressor be allowed to run in a vacuum When most of the refrigerant is isolated in the condensers recover remaining charge into separate refrigerant cylinders appropriate for the refrigerant being serviced Carefully track the amount of refrigerant cha...

Page 94: ...repair Note that the dryer will readily absorb moisture from the ambient air and must be open only for as long as required for installation After completion of all repairs pressure test system using nitrogen pressure decay test or nitrogen with tracer gas and appropriate leak detector Evacuation Carefully inspect pump and related equipment before connecting to system Ensuring gaskets are in good c...

Page 95: ...e above 1 000 microns in 10 minutes timeframe If unsuccessful continue evacuation or check for leaks It is anticipated that the system was clean and tight from the original process and refrigerant only is mixed with oil Alternative process should not be considered if there is chance of free water entering the system or the system was open for any significant time Charging Charge should be weighed ...

Page 96: ...em is operating as expected before the unit is returned to normal service Test component replaced and function of the system Many times a separate component in the system may have set a condition that causes a failure of another Thoroughly test systems to ensure repeat failures do not occur 5 7 System Rating Plate The system rating plate is attached near the electrical enclosure of the dehumidifie...

Page 97: ...e that the dehumidifier has been properly integrated with the rest of the equipment on the jobsite Finally he can train the maintenance personnel to operate and service the equipment if necessary A factory start up does not include installation assistance The installing contractor is responsible for ensuring that the system is ready for start up when the Desert Aire representative arrives When the...

Page 98: ...re additional field charging Refer to the charge label affixed to the unit for details Refrigerant added __________lbs if applicable Gas heater lines plumbed and purged Record gas pressure entering the unit ________ wc if applicable Refrigeration line set is clamped and the header supported per the Air Cooled O manual sec 2 3 Pressure transducer and cord sent with the remote condenser installed on...

Page 99: ...________________________ If you are unable to supply any of the required equipment you must contact Desert Aire before returning this document I agree that all of the above has been completed as of _____________ Date If a return trip must be scheduled due to insufficient job site preparation an additional purchase order must be issued to Desert Aire for re scheduling A two week minimum is needed t...

Page 100: ... the unit are noted on this form The model and serial number can be found on the system s rating plate located on or near the electrical compartment service door Failure to complete and return this form will void the unit s warranty These reports are also helpful when trying to correct existing problems Should you need system diagnosis help fax the completed worksheet to Desert Aire s Service Depa...

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Page 107: ...r more legs Compressor drawing higher current than design Continuity 0 resistance between two or more legs 3 phase units Compressor drawing locked rotor current Other describe Runs without pumping Pressures _____ _____ Final Determination of Failure Liquid Floodback Low Superheat Debris Defective Expansion Valve Low Sump Oil Insufficient Motor Cooling Other Describe Diagnostic Corrective Action Su...

Page 108: ...Circuit B Use both sides for tandem set Motor See wiring schematic for details Discharge Pressure PSIG PSIG PSIG PSIG Liquid Line Pressure At access fitting nearest TXV PSIG PSIG PSIG PSIG Suction Pressure At compressor PSIG PSIG PSIG PSIG Liquid Line Temperature At access fitting nearest TXV F F F F Suction Temperature At Compressor F F F F Refrigerant Sight Glass Condition Clear Intermittent Vap...

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Page 110: ...MIZING SOLUTIONS THROUGH SUPERIOR DEHUMIDIFICATION TECHNOLOGY N120 W18485 Freistadt Road Germantown WI 53022 E mail info desert aire com Ph 262 946 7400 Fax 262 946 7401 Website www desert aire com 460 2019 09 ...