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Dedicated Outdoor Air Unit

8

Additional Clearances for  

Packaged DX Units

Packaged DX units require additional clearance 
because they must have unrestricted air movement 
around the condenser coil and condenser fans. Hot air 
is being discharged from the condenser fans during 
operation. Enough clearance must be provided to 
avoid recirculation or coil starvation. When equipped 
with condenser coils, the unit should never be placed 
under an overhang or inside a building. A minimum of 
48 inches above the condenser fans is acceptable, but 
unobstructed is strongly recommended.  

END VIEW OF MAKE-UP AIR UNIT

WITH PACKAGED DX

Minimum 48 inches clearance

Minimum 18 inches 

clearance

Condenser Coil

Condenser Fans

End view of rooftop unit with Packaged DX

Installation

Additional Clearances for  

Air Source Heat Pump

Air-source heat pump units require additional clearance 
because they must have unrestricted air movement 
around the outdoor coil and outdoor fans. Enough 
clearance must be provided to avoid recirculation or 
coil starvation. Air-source heat pump units should 
never be placed under an overhang or inside a building. 
A minimum of 48-inches above the outdoor fans is 
acceptable, but unobstructed is strongly recommended.

IMPORTANT

Air-source heat pumps are equipped with a defrost 
cycle to remove ice from the outdoor coil. During 
defrost cycles, melted water may drip from the bottom 
of the refrigeration section under the outdoor coil. 
In cold climates, proper drainage/heat tape must be 
installed under the outdoor coil to prevent the buildup 
of ice on the roof.

Handling Concerns for 

Packaged DX or Air-Source Heat Pump

Units with PDX or ASHP have a system that is 
pressurized with refrigerant. If damage occurs, the 
refrigerant could leak into the atmosphere or cause 
bodily harm due to the extreme cold nature of 
expanding refrigerant. Use protective equipment such 
as gloves and safety glasses to minimize or prevent 
injury in case of a system leak during installation.

Before Lifting 

Before lifting, be sure that all shipping materials have 
been removed from the unit.

Vestibule

Determine whether or not the unit has a vestibule that 
must be field-attached to the side of the unit. Vestibules 
are shipped assembled but detached from the unit. 
They have lifting lugs on them so they can also be lifted 
by crane, but the installed location of the unit may make 
it preferable to install the vestibule on the unit prior to 
lifting.

Field Power Access

Determine where high voltage and low voltage wiring is 
to be brought into the cabinet. If wiring is to be brought 
into the cabinet through the floor, see Alternate Supply 
Entry Locations in this manual. If unit is to be installed 
on a roof, cut access openings in the roof deck as 
needed.

Содержание VX Series

Страница 1: ...ause bodily harm CAUTION When servicing the unit the internal components may be hot enough to cause pain or injury Allow time for cooling before servicing Only qualified personnel should install and m...

Страница 2: ...Piping Installation 12 Electrical Information 13 Control Center Components 14 Component Operation 15 Optional Component Operation 15 18 Factory Installed Refrigeration System 19 21 Start Up Unit 22 2...

Страница 3: ...f dirt water ice or snow and wipe dry before moving to indoor storage To avoid condensation allow cold parts to reach room temperature Leave coverings loose to permit air circulation and to allow for...

Страница 4: ...ilable on VX VXE 311 and 352 Packaged DX and ASHP units are shipped fully charged with refrigerant and are ready for operation upon arrival Heating There are three different optional heat sources that...

Страница 5: ...ng 311 uses furnace model PVF 200 600 or model HMA 700 800 Housing 352 use furnace model HMA 600 1200 Packaged DX System Any unit may be ordered with a packaged DX system Housing size 112 will include...

Страница 6: ...224 22 27 30 8 300 VXE 352 30 70 99 5 96 263 307 47 NA 10 450 Bottom or Side Side All dimensions are shown in inches Weight is shown in pounds and includes largest supply and exhaust fans PDX with re...

Страница 7: ...Unit Size ACS Access Side CC Control Cabinet End OAI Outdoor Air Intake NA from Unit NA from Condensing Section NA from Piping Vestibule not shown Other Indoor Mounted with IG Furnace Outdoor Mounted...

Страница 8: ...with a defrost cycle to remove ice from the outdoor coil During defrost cycles melted water may drip from the bottom of the refrigeration section under the outdoor coil In cold climates proper draina...

Страница 9: ...openings Guide unit while lowering to align with duct openings Roof curbs fit inside the unit base Make sure the unit is properly seated on the curb and level 5 Install Vestibule If unit was ordered w...

Страница 10: ...an L configuration and the area directly beneath the heat source must not have any openings such as louvers or grates No louvers or grates Installation Typical Unit Installed on Rails Supplied by Oth...

Страница 11: ...rvice and gas supply be brought into the cabinet through the end wall as shown below There are three penetrations into the cabinet that are required one for high voltage supply wiring one for low volt...

Страница 12: ...epted industry standards Pipework should be supported independently of the coils Undue stress should not be applied at the connection to coil headers 2 The condensate drain pipe should be sized adequa...

Страница 13: ...isconnect and must be compatible with the ratings on the nameplate supply power voltage phase and amperage Consult ANSI NFPA 70 and CSA C22 1 for proper conductor sizing Provide the Opening s for the...

Страница 14: ...Outdoor airflow monitor 17 Exhaust airflow monitor 18 Digital scroll controller Optional Indirect Gas Fired Furnace Note In some models two furnaces are installed to provide greater output When two fu...

Страница 15: ...ain room air temp at a desired set point Optional 0 10 VDC by others to VFD Supply fan is modulated by a 0 10 VDC field provided by others Component Operation Exhaust Fan VFD Sequence Optional Buildin...

Страница 16: ...ling mode the following conditions must be true 1 Supply air temperature above minimum low supply temperature limit 35 F 2 Outside air temperature above the cooling ambient lockout 55 F adj To operate...

Страница 17: ...en the system undergoes test and balance Hot Gas Reheat Valve Units equipped with a reheat coil use a three way valve with actuator to control the supply air discharge temperature of the unit during d...

Страница 18: ...l be fully programmed at the factory Optional Component Operation Rotation Sensor The rotation sensor monitors energy wheel rotation If the wheel should stop rotating the sensor will close a set of co...

Страница 19: ...ble and is located on the side of the evaporator coil and can be accessed through the coil access panel 13 Evaporative Coil 14 Low Limit Pressure Switch The switch is installed on the suction line and...

Страница 20: ...Source Heat Pump with Three Way Hot Gas Reheat 4WV Outdoor Coil Indoor Coil Outdoor Airflow Hot Gas Reheat Coil Supply Airflow Compressor PT HRV LPS SG SG EXV FDS HPS SV HCV ACC 4WV Outdoor Coil Indoo...

Страница 21: ...rsing valve to reverse the direction of refrigerant flow switching the unit between heating and cooling mode 12 Electronic Expansion Valve EXV or Thermostatic Expansion Valve TXV An expansion valve is...

Страница 22: ...or Allow 5 minutes between on cycles to prevent compressor damage DX system is charged with refrigerant Start up must be performed by EPA Certified Technician Start Up Unit Every installation requires...

Страница 23: ...ital scroll compressor The variable speed compressor uses internal stator heating Each compressor needs power supplied to it 24 hours prior to start up If start up is scheduled in 24 hours unlock the...

Страница 24: ...Energy Wheel Motor if equipped L1 Amps L2 Amps L3 Amps Condensing Fans PDX only Condensing Fan 1 L1 Amps L2 Amps L3 Amps Condensing Fan 2 L1 Amps L2 Amps L3 Amps Condensing Fan 3 L1 Amps L2 Amps L3 Am...

Страница 25: ...ween 10 and 20 F 0 reheat or should be between 10 and 30 F 100 reheat Deg F Deg F Deg F Deg F Subcooling Models VX VXE 352 Should be between 10 and 15 F 0 reheat or should be between 2 and 10 F 100 re...

Страница 26: ...n Line Temp Deg F Deg F Moisture Indicating Sight Glass Liquid Visible Yes No Yes No Color of Center Dot Purple Pink Purple Pink Heating Superheat Should be between 10 and 20 F Deg F Deg F Subcooling...

Страница 27: ...ntrol center door Vibration Excessive vibration may be experienced during initial start up Left unchecked excessive vibration can cause a multitude of problems including structural and or component fa...

Страница 28: ...ess ENTER 7 Set number of flows and press ENTER 8 Set flow and press ENTER 9 Set flow to actual CFM measured by Test and Balance and press ENTER 10 Wait for calibration before cycling power 11 Proceed...

Страница 29: ...re that you do not have power at the alert signal leads The unit is now ready for operation Setscrew on front of switch must be manually adjusted after the system is in operation Negative pressure con...

Страница 30: ...the factory but are field adjustable The VFD will be fully programmed at the factory Optional Energy Wheel Start Up If selected the energy wheel is installed in the unit s airstream with one half of...

Страница 31: ...e when a clip is open the clip will jam against the bearing support bar and could cause damage Cleaning Maintenance or cleaning of the wheel segments should be done with the segments removed from the...

Страница 32: ...dition is corrected It is located in the main control center Variable Frequency Drive VFD Variable frequency drives have a display screen that will show an alarm condition If a fault such as a voltage...

Страница 33: ...rted windings in motor Replace motor Low airflow cfm Unit damper not fully open Adjust damper linkage or replace damper motor System static pressure too high Improve ductwork to eliminate losses using...

Страница 34: ...and repair Replace fuse after correcting problem Low line voltage Check line voltage If more than 10 from compressor marking correcting is necessary Compressor motor protector open Motor thermal prote...

Страница 35: ...for two hours Recheck for open circuit Improper refrigerant charge Check subcooling Improperly wired Review wiring schematics Loose wiring Check all connections Defective start relay Replace relay Mot...

Страница 36: ...sible air recirculating Clean coil Condenser fan motor defective Check condenser fan motor Too much refrigerant Check subcooling Remove excess refrigerant Non condensable in system Remove non condensa...

Страница 37: ...ings Refrigerant flood back Check thermal expansion valve setting Check for refrigerant overcharge Check crankcase heater operation Reheat flush cycle inadequate Contact factory Not enough capacity or...

Страница 38: ...ntenance session and observations and then establish a maintenance schedule that is appropriate for the installation The following is provided as a guideline Maintenance Frequency Monthly 1 External F...

Страница 39: ...ces only Removing dust and grease buildup on the motor housing assists proper cooling Never wash down the motor with high pressure spray Greasing of motors is only intended when fittings are provided...

Страница 40: ...0x25x2 2 20x25x2 4 20x20 VXE 212 4 25x25x2 4 16x25x2 4 16x25x2 8 16x25 VXE 311 6 20x25x2 7 16x20x2 7 16x20x2 12 16x20 VXE 311 6 25x25x2 8 20x20x2 20x24x2 8 20x20x2 20x24x2 12 16x20 VXE 352 30 40 tons...

Страница 41: ...212 300 14 8 23 3 38 1 44 1 6 6 6 400 6 6 6 500 14 9 23 6 25 2 57 1 6 6 6 B A C D 500MBH 300 400MBH A B C D 200 300MBH 100 150MBH C A B D C A B D COMBUSTION AIR INLET EXHAUST OUTLET IG FURNACE ACCESS...

Страница 42: ...ng Location Model Furnace Size MBH A B C D E F G H I J Inlet Dimensions Outlet Dimensions Length Height Edge Thickness Length Height VX VXE 352 600 6 13 8 17 2 20 5 50 NA NA NA NA NA 21 5 6 1 6 5 5 5...

Страница 43: ...X 112 15I 3775 VX 112 15D 3775 VX 112 15S 3775 VX 112 15A 4300 VX 212 15I 4100 VX 212 15D 4100 VX 212 15S 4100 VX 212 15A 4800 Model Airflow SCFM VX 212 17 5I 4650 VX 212 17 5D 4650 VX 212 17 5S 4650...

Страница 44: ...8th Avenue North Minneapolis MN 55411 Main 612 877 4800 MORE INFORMATION UNIT SCHEMATICS For configuration and connection questions see the schematics that shipped with your unit They can typically be...

Страница 45: ...ause bodily harm CAUTION When servicing the unit the internal components may be hot enough to cause pain or injury Allow time for cooling before servicing Only qualified personnel should install and m...

Страница 46: ...ntenance session and observations and then establish a maintenance schedule that is appropriate for the installation The following is provided as a guideline Maintenance Frequency Monthly 1 External F...

Страница 47: ...ces only Removing dust and grease buildup on the motor housing assists proper cooling Never wash down the motor with high pressure spray Greasing of motors is only intended when fittings are provided...

Страница 48: ...0x25x2 2 20x25x2 4 20x20 VXE 212 4 25x25x2 4 16x25x2 4 16x25x2 8 16x25 VXE 311 6 20x25x2 7 16x20x2 7 16x20x2 12 16x20 VXE 311 6 25x25x2 8 20x20x2 20x24x2 8 20x20x2 20x24x2 12 16x20 VXE 352 30 40 tons...

Страница 49: ...including proper refrigerant charge and repair of minor refrigerant leaks outside the coil At the completion of start up an approved start up record must be submitted to the Unison service department...

Страница 50: ...te of shipment from the Unison factory whichever occurs first The ship date for the units noted above is 5 4 2020 Please refer to the Unison Comfort Technologies terms and conditions of sales for addi...

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